FUNDAMENTALS OF MECHANICAL ENGINEERING.pdf

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Fundamentals of
For Diploma & Bachelor Engineers
MECHANICAL
ENGINEERING
Mr. SAID AL-JABRI
2017

I
CONTENTS
CONTENTS ..................................................................................................................I
CHAPTER 1 .............................................................................................................1
1. ENGINEERING MATERIALS .......................................................................................1
1.1 CLASSIFICATION OF ENGINEERING MATERIALS ......................................................2
1.2 PROPERTIES OF MATERIALS ...................................................................................6
1.3 STRUCTURE OF MATERIALS ...................................................................................9
CHAPTER 2 .............................................................................................................10
2. FLUID POWER...........................................................................................................10
2.1 FLUIDS MECHANICS AND FLUID PROPERTIES ..........................................................11
2.2 PRESSURE AND ITS MEASUREMENT........................................................................12
2.3 LAMINAR AND TURBULENT FLOW..........................................................................13
2.4 FLUID FLOW ANALYSIS ..........................................................................................13
2.5 CONTINUITY AND BERNOULLI'S EQUATION ............................................................14
2.6 FLUID LOSSES IN PIPES ...........................................................................................15
2.7 FLUID POWER SYSTEM ...........................................................................................15
2.8 HYDRAULIC PUMPS & GAS COMPRESSORS .............................................................16
2.9 HYDRAULIC & PNEUMATIC ACTUATORS ................................................................18
2.10 HYDRAULIC & PNEUMATIC VALVES.....................................................................19
2.11 SEALS ..................................................................................................................21
2.12 FILTERS ...............................................................................................................21
2.13 ACCUMULATORS & RESERVOIR ...........................................................................21
2.14 HYDRAULIC FLUIDS .............................................................................................23
2.15 TURBINES ............................................................................................................23
2.16 TUBE AND PIPE REQUIREMENTS ...........................................................................24
CHAPTER 3 .............................................................................................................27
3. HEAT TRANSFER ......................................................................................................27
3.1 CONCEPT OF HEAT .................................................................................................28
3.2 HEAT TRANSFER ....................................................................................................31
CHAPTER 4 .............................................................................................................33
4. MECHANICS OF MACHINE.........................................................................................33
4.1 NEWTON'S LAW – KINEMATICS - KINETICS .............................................................34
4.2 CONCEPTS OF MECHANISMS...................................................................................36
4.3 COMPUTER SIMULATION OF MECHANISMS ............................................................38
4.4 BALANCING OF ROTATING AND RECIPROCATING MASSES ......................................38
4.5 CAMS AND FOLLOWERS .........................................................................................38
4.6 GEARS DRIVES ......................................................................................................40

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4.7 BELT DRIVES .........................................................................................................42
4.8 WIRE ROPES ..........................................................................................................44
4.9 BREAKS ................................................................................................................45
4.10 CLUTCHES ...........................................................................................................46
CHAPTER 5 .............................................................................................................48
5. THERMODYNAMICS .................................................................................................45
5.1 THERMODYNAMICS 1.............................................................................................49
5.2 THERMODYNAMICS 2.............................................................................................50
CHAPTER 6 .............................................................................................................70
6. PHYSICS...................................................................................................................70
6.1 MAGNETISM...........................................................................................................71
6.2 WAVES ..................................................................................................................73
6.3 REFLECTION AND REFRACTION OF LIGHT...............................................................75
6.4 AC CIRCUITS ..........................................................................................................77
6.5 KINETIC THEORY OF GASES....................................................................................80
6.6 MODERN PHYSICS ..................................................................................................82
CHAPTER 7 .............................................................................................................84
7. CHEMISTRY .............................................................................................................84
7.1 CHEMICAL FORMULAE AND EQUATIONS ................................................................85
CHAPTER 8 .............................................................................................................94
8. MATHEMATICS.........................................................................................................94
8.1 FORMULAS ............................................................................................................95

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1.1 Classification of Engineering Materials:
1. Metals
2. Polymers
3. Ceramics
4. Composites
5. Semiconductors
 Properties of metals:
1. They have shiny surface
2. They are good conductor of heat and electricity
3. They are strong material
4. They are ductile- they can easily made into wire
5. They are malleable- they can easily made into different sheet
6. They are formable- they can easily made into different shapes
7. They have high melting points
8. They are heavy
 Metals: Types of metals are Pure metals & alloys
1. Pure metals:
 Metals in clear form or unmixed form.
 They are better conductor of electricity and heat than alloys.
 They are more ductile, malleable and formable than alloys.
 They are soft than alloys.
 Examples of pure metals are Copper, Aluminum, Tin and Tungsten.
a) Copper is used to make automobile radiator sheets, bottoms of cooking,
pipes of heat exchangers, electrical wire cable and motor winding.
Because it is good thermal conductivity,good electrical conductivity,
ductile, malleable, low cost, more availability and easy for manufacturing.
b) Aluminum is used to make soft drink cons, windows frame, food storage
foils. Because it is corrosion resistance, malleable, low cost, more
availability and easy for manufacturing.
c) Tin is used to cover the surface of materials, because it is corrosion
resistance.
d) Tungsten is used for filament in bulbs, because of its high melting point,
corrosion resistance.
2. Alloys:
 Alloys are mixture of two or more metals.
 They are stronger and harder than pure metals.
 Examples of alloys are Steel, Stainless Steel, High Speed steel (HSS), Brass, Cost
Iron, Duralumin and Bell metal.
1) Steel is made by mixing Iron and Carbon. Types of steel:
i. Low carbon steels
 If the percentage of carbon in steels are between 0.05-0.15%
 They are used for structure bars, automobiles bodies, and
furniture.
 They have good strength, ductile, malleable, formable and
easy for welding process.

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ii. Mid steels
 Used and properties same to Low carbon steel.
iii. Medium carbon steels
 They are used to make Shaft, Bolts and Nots. Because they
are more strength compared to low carbon and mid steel.
iv. High carbon steel
 They are used to make springs and ropes. Because they have
more strength compared with low carbon steels, mild steel
and high carbon steels.
v. Ultra-high carbon steels
 If the percentage of carbon in steels are between 1-2%
 They are used to make automobiles axles, workshop
punches, workshop scribers, workshop dividers. Because they
are very strong and hard compared to all other carbon steels.
2) Stainless steel is made by mixing Iron, Carbon, Chromium and Manganese
 It is used to make Vernier caliper, workshop ruler, bearing of
machines, spoons, knives, plates, cups, surgical equipment.
 They are good strength, corrosion resistance, shiny surface,
ductile, malleable, and formable.
3) High Speed steel (HSS) is an alloy of Iron, Carbon, tungsten, Chromium
and vanadium.
 It is used to make cutting tools of various machines and
workshop files.
 It has high hardness, high strength, high toughness, easy for
re-sharping and low cost.
4) Brass is made by mixing Copper and Zinc.
 It is used to make heat exchanger pipes and ship parts.
 It is stronger than Copper, good conductor of heat, malleable,
low cost and corrosion resistance.
5) Cost Iron is made by mixing Iron, more than 2% of Carbon, silicon and
Manganese.
 It is used to make machine tool bases.
 It is easy for casting, easy for cutting, medium hardness,
absorb vibration and low cost.
6) Duralumin is an alloy of Aluminum, Copper, Magnesium and Manganese.
 It is used for making aircraft body, light truck wheels, light
rivets.
 Because it has high strength, light weight, easy for shaping.
7) Bell metal is an alloy of Bronze, Copper and tin.

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 It is used for making of Cannons, because it is easy for
casting, good strength, toughness and hardness and easy for
machining.
 Polymers (Plastics): They are compounds of carbon molecules joined together in long chains.
a) Properties of polymers:
1. They are insulator of heat and electricity
2. They have moderate strength
3. They are corrosion resistance
4. They are light in weight
5. They are they are ductile and malleable
6. They have low melting point
b) Types of polymers:
1. Thermoplastics
2. Thermosetting plastic
3. Elastomers
i. Thermoplastics
 Poly-ethylene (PE), Poly-Vinyl-Chloride (PVC) and Nylon are
the examples of thermoplastics.
 They are used for making of bags(PE), water pipes(PVC),
electric cable insulators(PE), bottles(PE) and low strength
gear for toys(Nylon)
 Because they are soft, flexible, easy for manufacturing, light
weight, they can be recycled and low cost.
ii. Thermosetting plastic
 Bakelite is an example for thermosetting plastic.
 It is used for making of TV covers, phone covers, handles of
cookers and knobs
 Because it has more strength and hardness compared to
thermoplastics.
iii. Elastomers
 These plastics are highly elastic in nature.
 Rubber is an example of elastomer; it is used for making of
automobile tires.
 Because it is highly elastic and absorbs vibrations.
 Ceramics: are metallic and non-metallic oxides, carbides or nitrides.
a) Examples of Ceramics:
1. Aluminum Oxide (Alumina)
2. Silicon Nitride
3. Tungsten Carbide
4. Glass
5. Cement
6. and Sand

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i. Alumina, Silicon Nitride are used for making of grinding machine
wheels and grinding machine belt. Because they are very hard, heat
resistant and can cut easily other engineering materials.
ii. Tungsten Carbide is used for making of cutting tools of machines like
lathe, milling machine etc. Because it is very hard, heat resistant and
can cut easily other engineering materials.
b) Properties of Ceramics:
1. They are very hard compared to other engineering materials.
2. They are brittle materials.
3. They are heat resistant materials (refractory materials).
4. They have high melting point.
5. They are corrosion resistant.
6. They are insulators of heat and electricity.
 Composite Materials: are made by mixing metal and non-metal or by mixing two different non-metals.
a) Different phases of composite materials:
1. Major phase called Matrix
2. And Minor phase called Reinforcement.
b) Examples of composite materials:
1. FBR (Fiber reinforced Plastic)
2. RCC (Reinforced Concrete Cement)
3. C/C composite material (Carbon Fiber Reinforced Carbon).
i. FBR (Fiber reinforced Plastic) is used for making safety helmets,
sports car parts, wind turbines and light weight boats.
ii. RCC (Reinforced Concrete Cement) is made by mixing Steel and
Concrete. It is used for construction of buildings and structures.
iii. C/C composite material (Carbon Fiber Reinforced Carbon) is made
by mixing graphite and carbon fiber. It is used for brake discs of
formula one car. Because it is hard and have good frictional
properties.
 Semiconductors: They are materials with partial electrical conductivity. They are used for making of
Electronics Boards, Diodes, Capacitors and transformers.
a) Examples of semiconductors
1. Silicon
2. Germanium
b) Properties of semiconductors:
1. they are partial conductors of electricity and heat
2. they are brittle
3. they have low strength

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1.2 Properties of Materials
2. Mechanical Properties
3. Electrical Properties
4. Chemical Properties
5. Thermal Properties
6. Physical Properties
 Mechanical Properties Behavior of a material under action of force.
1. Strength
2. Elastic limit
3. Modulus of elasticity
4. Ductility / Brittleness
5. Toughness
6. Hardness
a) Stress- Strain:
i. Stress:
 It is the ratio of force and area.
 Stress = Force/Area, SI Unit N/m2
or Pa
ii. Strain:
 It is the ratio of change in length (Extension) to the original length.
 Strain = Lf – Lo / Lo, No unit
 Percentage Elongation = Strain * 100
iii. Hooke's Law: stress is directly proportional to strain.
stress-strain curve
A. Elastic Limit: the limit that when force is removed, material comes
back to its original shape.
B. Upper yield point: the point at which yielding observed at higher
stress value.
C. Lower yield point: the point at which yielding observed at lowest
stress value.
D. Ultimate tensile strength: the maximum stress that material can
withstand before it breaks.
E. Breaking or Fracture point: the point at which material breaks.
b) Modulus of elasticity (Young's Modulus):
 It is the ratio of stress and strain.
 Modulus of elasticity (E) = Stress/Strain
 If a material has more modulus of elasticity, it has more stiffness.

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c) Ductility:
 When a material deforms more before fracture.
 It is very important property for making of wire.
 Pure metals like Gold, Silver, Copper and Aluminum are examples of ductile
materials.
d) Brittleness:
 When a material deforms less before fracture.
 Brittle materials fail suddenly without warning.
 Ceramics like Glass, Alumina and Silica are examples of brittle materials.
Stress-Strain Curves for Ductile and Brittle Materials
e) Toughness:
 Ability of a material to absorb energy before fracture.
 Ductile materials have more toughness than brittle materials.
 Toughness is measured in Joule.
 Toughness is measured using Charpy and Izod Testing Machine.
Charpy and Izod Testing Machine
f) Hardness:
 It is the resistance to indentation.
 It is measured by force applied divided surface area of indentation (N/m2
)
 Machines used for testing hardness are Brinell hardness tester, Vickers
hardness Tester and Rockwell Hardness Tester.
 Hardest natural material is Diamond.
Hardness Testing

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 Electrical Properties: Behavior of a material under action of force. It is useful for making electrical
products like wire, Motor etc.
1. Electrical Conductivity
2. Electrical Resistively
3. Dielectric Strength
a) Electrical Conductivity:
 It is ability of a material to pass electrical current.
 Conductivity: Silver > Copper > Aluminum
b) Electrical Resistively:
 It is ability of a material to resist the flow of electrical current.
 High electrical resistivity materials are used as Insulator.
 Resistivity: Polymers = Ceramics > Metals
c) Dielectric Strength:
 It is ability of a material to withstand high voltage without breaking.
 Dielectric Strength: Polymers > Ceramics > Metals
 Chemical Properties: Behavior of a material under Chemical Reactions.
1. Important Chemical Properties is Corrosion.
2. Corrosion is Oxidation of materials by react with Oxygen.
3. Methods used to stop corrosion are Painting, Cleaning, electro-plating, galvanization,
cathodic protection and chloride extraction.
4. Corrosion Resistance: Ceramics = Polymers > Metals
 Thermal Properties: Behavior of a material under the action of heat.
1. Co-efficient of linear expansion
2. Specific heat
a) Co-efficient of linear expansion:
 Materials expand when temperature increases.
 High Co-efficient means, material expands more with small temperature.
 Co-efficient of linear expansion: Polymers > Metals > Ceramics
b) Specific heat:
 The amount of heat energy required to rise the temperature of 1 Kg of
substance by 10
.
 Specific heat (C) =
Heat Energy
Mass × Change in Temperature
, SI units- J/Kg.K
 High specific heat means, more heat energy required to rise its temperature.
 Specific heat: Polymers = Ceramics > Metals
 Physical Properties: Behavior of a material under changing the composition.
1. Density
2. Specific Strength
a) Density:
 It is the ratio of Mass and Volume.
 P = m/V , SI unit Kg/m3
 High density materials are heavier compared to low density materials.
b) Specific Strength:
 It is the ratio of strength and density. SI unit Pa/Kg.m-3

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1.3 Structure of Materials
 Structure means arrangement. Structure of materials is arrangement of atoms in materials.
 Classification of engineering materials based on structure:
1. Crystalline Materials: If the atoms arrangement in material is regular order.
 Examples of Crystalline Materials are Pure Metals, Alloys, some Ceramics and
Semiconductors.
2. Partially Crystalline Materials: If the atoms arrangement in material is regular order and
irregular in other areas. Example: Polymers
3. Non-Crystalline (Amorphous) Materials: If the atoms arrangement in material is irregular
order.
 Ex: Wood, Composite materials and some Ceramics.
 Different between the properties of Amorphous and Crystalline Materials:
Amorphous Materials Crystalline Materials
1. They have low strength
2. They are light in light
3. They are brittle
4. They are insulator of heat and
electricity
1. They have high strength
2. They are heavy
3. They are ductile
4. They are conductor of heat and
electricity

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2.1 Fluids Mechanics and Fluid Properties
 Fluid mechanics is the branch of engineering which deals with behavior of fluid at rest & motion
 There are three states of matter: Solid, Liquid and Gas. Liquid and gas are both fluids.
 Difference between Liquids & Gasses
Liquids Gasses
 It is difficult to compress & incompressible.
 It has fixed volume.
 It is easily to compress
 It has no fixed volume; its volume changes with pressure.
 Properties of Fluids:
1. Density:
 It is the mass per unit volume.
 Ρ=
𝑚
𝑉
𝑘𝑔/𝑚3
 ρ𝑤𝑎𝑡𝑒𝑟 = 1000 𝑔/𝑚3
, ρ𝑎𝑖𝑟 = 1.23 𝑘𝑔/𝑚3
, ρ𝑚𝑒𝑟𝑐𝑢𝑟𝑦 = 13546 𝑘𝑔/𝑚3
2. Specific Weight or Weight density:
 It is the weight per unit volume.
 ω=
𝑊
𝑉
𝑁/𝑚3
, 𝑤 = 𝑚𝑔 𝑁
3. Specific Gravity or Relative Density:
 It is the ratio of density of substance to standard density.
 For solids and liquids the standard density is the density of water.
 𝜎 =
𝜌𝑠𝑢𝑏𝑠𝑡𝑎𝑛𝑐𝑒
𝜌𝑤𝑎𝑡𝑒𝑟
𝑘𝑔/𝑚3
, 𝜎𝑤𝑎𝑡𝑒𝑟=1
4. Viscosity:
 It is the resistance of fluid flow.
 Fluid with high viscosity flows more slowly than fluid with a low viscosity.
 Newton's Law of Viscosity: shear stress is directly proportional to the rate of
change of velocity.
 Classification of fluids:
1. Ideal fluid:
 Fluids which have no viscosity and surface tension.
 They are incompressible and not exist in nature.
 Fluids with low viscosity like water and air maybe classify as ideal fluid.
2. Real fluid:
 Fluids which have viscosity & surface tension.
 They are compressible and exist in nature.
3. Newtonian fluid:
 Fluids which follow Newton's law of viscosity like water, air, petrol.
4. Non-Newtonian fluid:
 Fluids which don't follow Newton's law of viscosity like printer ink.

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2.2 Pressure and its measurement
 Pressure: It is the force per unit area. 𝑝 =
𝐹
𝐴
𝑁/𝑚2
or Pa or SI unit bar ( 1 bar=105
𝑁/𝑚2
)
 Pascal's Law for Pressure: Pressure at any point in a fluid is the same in all directions.
 Absolute pressure and Gauge pressure: 𝒑𝒂𝒃𝒔𝒐𝒍𝒖𝒕𝒆=𝑷𝒈𝒂𝒖𝒈𝒆+𝑷𝒂𝒕𝒎𝒐𝒔𝒑𝒉𝒆𝒓𝒊𝒄
The pressure at the surface of fluids is the atmospheric pressure (Patmospheric), Pgauge= ρgh
 Pressure measurement by Manometer:
 Advantages of Manometers:
1. They are very simple
2. No calibration required
 Advantages of Manometers:
1. Slow response
2. Difficult to measure small variation in pressure
3. The density changes ( decreased) when temperature changes (increased
4. For "U" Tube Manometer, two measurements must be taken to get the "h" value
The Simple
(Piezometer) Tube
Manometer
pA=ρgh1 , pB= ρgh2
 The tube is open to the
atmosphere; so the pressure
measured is relative to atmosphere.
 This method can only used for
liquids not for gases and only when
the liquid height is easy to measure.
The "U" Tube
Manometer
PB=Pc
For the left hand arm:
PB=PA+ρgh1
For the right hand arm:
PC=PAtmosphere+ρmangh2
As we measure Pgauge subtract Patm
PB=PC
PA= ρmangh2- ρgh1
This method can use for both liquids
and gases.
Measurement of
Pressure
Difference Using a
"U" Tube
Manometer
PC=PD
PC=PA+ ρgha
PD=PB+ ρg(hb-h)+ ρmangh
PA+ ρgha =PB+ ρg(hb-h)+ ρmangh
The pressure difference:
PA-PB= ρg(hb-ha)+( ρman- ρ) gh
Tilted Manometer
The pressure difference:
P1-P2= ρgz2
=ρg xsinθ

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2.3 Laminar and Turbulent Flow
 Laminar flow: The fluid practices move regular and order in straight lines.
 Re<2000
 It is stable flow
 Low viscosity
 Dye doesn’t mix with water
 Fluid particles move in straight lines
 Turbulent flow: The fluid practices move irregular in jagged lines
 Re>4000
 It is unstable flow
 High velocity
 Dye completely mixes with water
 Fluid particles move irregular in jagged lines
 Most common type of flow
 Transitional flow: The fluid practices move in wave lines.
 2000> Re <4000
 Medium velocity
 Dye partly mixes with water
 Fluid practices move in wave lines
 The Reynolds number: Re=
𝑢𝑑
𝜇
=
𝑖𝑛𝑒𝑟𝑡𝑖𝑎𝑙 𝑓𝑜𝑟𝑐𝑒𝑠
𝑣𝑖𝑠𝑐𝑜𝑢𝑠 𝑓𝑜𝑟𝑐𝑒𝑠
,u=velocity, d=diameter
2.4 Fluid Flow Analysis
 Uniform Flow & Steady Flow
 Uniform flow: If the flow velocity is the same at every point in the fluid.
 Non-uniform Flow: If the flow velocity isn't the same at every point in the fluid.
 Steady Flow: The velocity & pressure at a point don’t change with time.
 Unsteady Flow: The velocity & pressure at a point change with time.
 Compressible & Incompressible Flow
 Compressible flow: The density of fluid changes from point to point. Example: flow of gases.
 Incompressible flow: The density of fluid is constant from point to point. Example: flow of
liquid. All fluids are compressible (their density will change) when pressure changes.
 Dimensional Flow
 One dimensional flow: The fluid flows in one direction only. Example: flow in pipe.
 Two dimensional flow: The fluid flows in two directions (x & y). Example: flow in parallel
pates.
 Three dimensional flow: The fluid flows in three directions. Example: flow in a convergent or
divergent pipe.
 Mass flow rate: It is the mass per unit time. Mass flow rate =
𝑚𝑎𝑠𝑠
𝑡𝑖𝑚𝑒
𝑘𝑔/𝑠
 Volume flow rate (Discharge): It is the volume per unit time. Q=
𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑓𝑙𝑢𝑖𝑑
𝑡𝑖𝑚𝑒
= 𝐴𝑢 𝑚3
/𝑠
A= area, u= velocity

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2.5 Continuity and Bernoulli's Equation
 Continuity Equation: It is a statement of mass conservation (matter cannot be created or destroyed)
Mass entering per unit time = Mass leaving per unit time
A1u1 = A2u2 = Q
 Applications of Continuity Equation:
1. Pipe with a contraction:
Q1 =Q2
A1u1 = A2u2
𝒖𝟐 = [
𝒅𝟏
𝒅𝟐
]𝟐
𝒖𝟏
𝑨 =
𝝅𝒅𝟐
𝟒
2. Pipe with expands or diverges:
Q1 =Q2
A1u1 = A2u2
𝒖𝟏 = [
𝒅𝟐
𝒅𝟏
]𝟐
𝒖𝟐
𝑨 =
𝝅𝒅𝟐
𝟒
3. Pipes coming from a junction:
Q1 =Q2 + Q3
A1u1 = A2u2 + A3u3
𝑨 =
𝝅𝒅𝟐
𝟒
4. Flow from a reservoir:
𝒖𝟏 = 𝟎
𝒖𝟐 = √𝟐𝒈(𝒛𝟏−𝒛𝟐)
𝑨 =
𝝅𝒅𝟐
𝟒
𝑸 = 𝑨𝒖
 Bernoulli's Equation: The sum of pressure head, velocity head and potential head is constant.
𝒑𝟏
𝝆𝒈
+
𝒖𝟏
𝟐
𝟐𝒈
+ 𝒛𝟏 =
𝒑𝟐
𝝆𝒈
+
𝒖𝟐
𝟐
𝟐𝒈
+ 𝒛𝟐
𝒑
𝝆𝒈
+
𝒖𝟐
𝟐𝒈
+ 𝒛 = 𝑯
𝒑
𝝆𝒈
= Pressure head,
𝒖𝟐
𝟐𝒈
= Velocity head, 𝒛 = Potential head, H= Total head
 Applications of Bernoulli's Equation:
1. Venture meter: It is a device used for measuring discharge in a pipe.
𝒑𝟏
𝝆𝒈
+
𝒖𝟏
𝟐
𝟐𝒈
+ 𝒛𝟏 =
𝒑𝟐
𝝆𝒈
+
𝒖𝟐
𝟐
𝟐𝒈
+ 𝒛𝟐
Z1=Z2
Q=A1u1 = A2u2
2. Flow through Orifice: The fluid flow thorough the sharp edged orifice.
(𝒖𝟏 = 𝟎), (𝒑𝟏 = 𝟎), (𝒑𝟐 = 𝟎), (𝒛𝟏 = 𝒉), (𝒛𝟐 = 𝟎)
𝒖𝟐 = √𝟐𝒈𝒉
𝑸 = 𝑨𝒖

15
3. Stagnation Pressure: the fluid goes to the head of blunt body and stops, because at
this point (stagnation point) the velocity is zero. Pressure at stagnation point called
Stagnation Pressure
(𝒛𝟏 = 𝒛𝟐), 𝒂𝒕 𝒑𝒐𝒊𝒏𝒕 𝟐 (𝒖𝟐 = 𝟎)
𝒑𝟏
𝝆𝒈
+
𝒖𝟏
𝟐
𝟐𝒈
+ 𝒛𝟏 =
𝒑𝟐
𝝆𝒈
+
𝒖𝟐
𝟐
𝟐𝒈
+ 𝒛𝟐
𝒑𝟐 = 𝒑𝟏 +
𝟏
𝟐
𝝆𝒖𝟏
𝟐
Stagnation Pressure = Static Pressure + Dynamic Pressure
4. Pilot Tube: Two piezometers, one as normal and one as pilot tube within the pipe
used to measure velocity of flow.
(𝒛𝟏 = 𝒛𝟐), (𝒖𝟐 = 𝟎)
𝒑𝟏
𝝆𝒈
+
𝒖𝟏
𝟐
𝟐𝒈
+ 𝒛𝟏 =
𝒑𝟐
𝝆𝒈
+
𝒖𝟐
𝟐
𝟐𝒈
+ 𝒛𝟐
𝒑𝟐 = 𝒑𝟏 +
𝟏
𝟐
𝝆𝒖𝟏
𝟐
𝝆𝒈𝒉𝟐 = 𝝆𝒈𝒉𝟏 +
𝟏
𝟐
𝝆𝒖𝟏
𝟐
𝒖𝟏 = √𝟐𝒈(𝒉𝟐−𝒉𝟏)
2.6 Fluid Losses in Pipes
 Losses due to friction: These losses depend on:
1. Roughness of the inside surface of the pipe
2. Reynolds number
 Losses due to pipe fittings: These include:
1. Bends
2. Valves
3. Sudden or Gradual Enlargement
4. Sudden or Gradual contraction
5. Exit loss
6. Entry loss ( similar to Sudden contraction )
2.7 Fluid Power System
 Fluid Power: It is deals with the generation, control and transmission of power, using Pressurized fluids
It is used to push, pull, regulate or drive of all the machines of industry.
 Difference between Hydraulics and Pneumatics:
Hydraulics Pneumatics
 The fluid is a liquid such as water, diesel and
petroleum.
 It is used for high pressure applications(4000 kN loads)
 The fluid is a gas such as air.
 It is used for low pressure applications
(30 kN loads)
 Advantages of fluid power:
1. Less loss of power, so more efficiency
2. Large force with great accuracy
3. Linear or rotary force can be multiplied the output power
 Disadvantages of fluid power:
1. Flammable hydraulic fluid may create fire hazards
2. Pneumatic system, such as compressor may create explosive

16
 Fluid power applications:
1. Manufacturing industry: Hydraulic presses, pneumatic hand tools, etc.
2. Automobile industry: Hydraulic brakes, Power steering, etc.
3. Material handling field: Hydraulic lift truck, Hydraulic jacks, Hydraulic elevators, etc.
4. Construction field: Earth moving equipment.
 Basic components of fluid power system:
 Hydraulic pump or air compressor: It converts mechanical power to fluid power.
 Actuator: It converts fluid power to linear or rotary mechanical power.
 Valves: They control direction, pressure and rate of flow.
 Filters: They remove particles pollutions from fluid.
 Tubes, Fittings, Coupling, etc: They link the fluid between components.
 Sealing devices: They help to contain the fluid.
 Accumulators and reservoirs: They store the fluid.
 Instruments such as pressure gauge, flow mater: They are used to monitor the
performance of fluid power system.
 Principle of Hydraulics or (Pascal's Law): When given load over
a smaller area, the force produced on a larger area is higher.
𝒑𝟏 = 𝒑𝟐 →
𝑭𝟏
𝑨𝟏
=
𝑭𝟐
𝑨𝟐
→ 𝑭𝟐 =
𝑭𝟏𝑨𝟐
𝑨𝟏
 Principle of Pneumatics or (Boyle's Law): The pressure of gas is
inversely proportional to its volume, when the temperature is constant.
𝒑 ∝
𝟏
𝑽
→ 𝒑𝟏𝑽𝟏 = 𝒑𝟐𝑽𝟐
2.8 Hydraulic Pumps & Gas Compressors
 Hydraulic Pumps: It is a mechanical device that increases the pressure of a liquid by reducing
its volume. It is the heart of hydraulic system. Symbol
 Gas Compressors: It is a mechanical device that increases the pressure of a gas by reducing
its volume. Symbol
 Classification of (Pumps & Compressors):
1. Non Positive Displacement (Pumps or Compressors) or (Centrifugal Pumps or Compressors):
 Use impeller to force the fluid to the volute casing which convert kinetic energy into
pressure energy.
 They are used for low pressure and high volume applications (up to 40 bar).
 They are used for fluid transportation and circulation etc.
2. Positive displacement (Pumps & Compressors):
 They apply pressure directly to the fluid by reciprocating piston or by rotating member.
 It is used for very high pressure fluids (up to 700 bar).
 They are used for variable viscosity applications.
 Classification of Positive displacement (Pumps & Compressors):
1. Reciprocating (Pumps & Compressors): In this pump or compressor, the chamber is
a stationary cylinder that contains piston or plunger. They are classified as:
i. Piston Pumps, ii. Plunger Pumps, iii. Diaphragm Pumps
2. Rotary (Pumps & Compressors): In this pump or compressor, the chamber moves from inlet to
discharge and back to the inlet. They are classified as:
i. Gear Pumps, ii. Lobe Pumps, iii. Screw Pumps, iv. Vane Pumps

17
Types How do they work Simple pictures
Centrifugal
Pumps
 Liquid forced into impeller from suction
eye.
 Vanes produce kinetic energy to liquid,
liquid rotates and leaves impeller.
 Volute casing converts kinetic energy into
pressure energy.
Centrifugal
Compressor
 Liquid forced into impeller from suction
eye.
 Vanes produce kinetic energy to liquid,
liquid rotates and leaves impeller.
 Diffuser decreases or converts kinetic
energy into pressure energy of gas.
Piston
Pumps &
Compressor
 When the piston moves to the left, it
creates vacuum inside the cylinder.
 Because pressure difference between
atmosphere pressure and cylinder
pressure, the liquid moves from tank to
cylinder by open inlet valve and close outlet
valve.
 When the piston stops, both valves are
closed and when the piston is starting
moves to the right, the pressure increased
and discharge valve open.
Plunger
Pumps &
Compressor
 The plunger moves back and forth by motor
driving.
 Because of pressure difference between
valve.
 When both valves are closed, the plunger
increases the pressure of liquid and then
discharge valve open and high pressure
liquid goes out.
Diaphragm
Pumps &
Compressor
 The diaphragm moves back and forth by
motor driving.
 Because of pressure difference between
valve.
 When both valves are closed, the
diaphragm increases the pressure of liquid
and then discharge valve open and high
pressure liquid goes out.
Gear Pump
&
Compressor
 They have two gears, one is connected to
the driver shaft and other is driven as its
meshes with the driver gear.
 As the gears come out of mesh, they create
expanding volume and low pressure on the
inlet side of the pump. Liquid flows into the
pump because pressure difference.
 Liquid travels around between teeth and
casing; they create compression volume
and high pressure.
 Finally, the gears go into mesh and forces
liquid through discharge under pressure.

18
2.9 Hydraulic & Pneumatic Actuators
 Hydraulic Actuators: They convert hydraulic energy of pump into mechanical power.
 Pneumatic Actuator: They convert pneumatic energy of compressor into mechanical power.
 Classification of Actuators:
1. Linear Actuators:
 They convert fluid energy into linear force and linear motion.
 They are cylinder-piston system which moves back and forth during the operation cycle.
 Types of linear Actuators:
i. Single acting type
ii. Double acting type
2. Semi-Rotary Actuator:
 They convert fluid energy into limited rotation or oscillatory motion.
 They are known as limited rotation motor.
 Types of Semi-Rotary Actuators:
i. Vane type
ii. Piston type
3. Rotary Actuators:
 They convert fluid energy into rotational motion.
 They are known as rotation motor.
 Types of Rotary Actuators:
i. Gear motor
ii. Vane motor
iii. Piston motor
Types of Rotary
Actuators
How do they work Simple pictures Symbols
Single acting type
 It has only one port at one end of the
cylinder.
 The fluid pressure enters from pressure
port and pushes the piston forward.
 When the fluid pressure is cut off, the
piston returns to its position by a spring.
Double acting
type
 It has two ports at both ends of the
cylinder.
 The fluid pressure enters from port 1
and pushes the piston forward.
 The fluid pressure is cut off from port 1
and start flow from port 2 to return
piston to its position.
Gear motor
 It is similar to gear pump & gear
Compressor.
 It is also similar to electric motors but is
run on hydraulic or pneumatic power.
 They have two gears, one is connected
to the driver shaft and other is driven as
its meshes with the driver gear.
 Compressed fluid enters from inlet and
rotates the gears and produced torque.

19
2.10 Hydraulic & Pneumatic Valves
 The pressurized fluid form Pump or Compressor is moved to the actuators using Valves.
 Valves are used to control:
1. Direction of flow
2. Pressure of flow
3. Quantity of flow
4. Stoppage of flow
 Classification of Valves:
1. Direction control valve (D.C. Valves):
 They are used to reverse the direction of actuator, and to start and stop piston
movement.
 Classification of D.C. Valves:
I) Based on construction:
1) Seat or Poppet valve
2) Spool valve or sliding valve
a) Rotary spool valve
b) Sliding spool valve
II) Based on Number of ports:
1) Two way valve (Check valves):
 It has two ports, it is also called non-return valves
 It is used to allow flow in only one direction.
 Poppet & pilot operated are types of check valves.
2) Three way valve
3) Four way valve
III) Based on number of ports & number of valve position:
1) Two way, two position valves (2/2 valves)
2) Three way, two position valves (3/2 valves)
3) Four way, two position valves (4/2 valves)
4) Four way, three position valves (4/3 valves)
IV) Based on the type of power source used:
1) Shuttle valve
V) Based on the mode of actuation of D.C. valves:
2) Manually operated D.C. valves
3) Mechanically operated D.C. valves
4) Solenoid operated D.C. valves
5) Pilot operated D.C. valves
2. Pressure control valve:
 They are used to reducing / increasing pressure, and providing maximum pressure
thereby ensuring safety.
 Classification of pressure control Valves:
I) Pressure relief valve:
1) Direct acting or simple pressure relief valve
2) Pilot operated or compound pressure relief valve
3. Flow control valve:
 They are used to control the speed of actuator by controlling the rate of fluid flow.
 Classification of pressure control Valves:
I) Globe valve
II) Needle valve

20
Type of
Valve
How do they work Simple pictures Symbols
Seat or
Poppet
valve
 It consists of poppet or ball, return spring
and push button.
 When push button is depressed, ball is
pushed out of its seat and fluid flow from
port 1 to port 2
 When push button is released, ball is
returned to its seat by spring and stop flow.
Flow path
Flow shut off
Valve
Push
button
Lever
Pedal
Plunger
Spring
Sliding
spool
valve
 It consists of small piston like spool placed
inside the valve body.
 The spool slides inside the valve body to
open and close the ports.
Pilot
operated
check
valve
 It allows the reverse flow.
 When fluid flow in the normal direction,
the fluid pressure pushed the poppet out
of its seat and fluid flow from port A to
port B.
 To allow the fluid flow in reverse
direction, the pilot pressure pushes the
pilot piston and the poppet down.
Poppet
type
check
valve
Position 1
 When fluid flow in the normal direction,the
fluid pressure pushed the poppet out of its
seat and fluid flow from port in to port out.
Position 2
When flow stop, the poppet returns to its
seat by spring and fluid can't pass in the
reverse direction.
Check valve
or Non-return
valve
The 2/2
D.C.
valve
Position 1
 When push button is depressed, ball is
pushed out of its seat and fluid flow from
port P to port A.
Position 2
 When push button is released, ball is
returned to its seat by spring and stop flow.
2/2 D.C. valve
open
2/2 D.C. valve
open
Shuttle
valve
 It is used when control more than one
power source.
 When the pressure in the right inlet port is
greater than the left port inlet, the shuttle
piston closes the left port.
 When the pressure in the left inlet port is
greater than the right inlet port, the shuttle
piston closes the right port.
4/2 D.C. valve
4/3 D.C. valve
Needle
valve
 It has a Stem that adjusted manually to
control flow rate.
 It has a smaller flow area and higher
pressure than Globe valve.
Simple
pressure
relief
valve
 It is used to prevent rising in the pressure.
 When the pressure exceeds set limit, the
fluid forced the spring to allow fluid to flow
to the tank port.
 Otherwise the valve is closed.

21
2.11 Seals
 Function of Seals:
a) Control of external and internal leakage of fluid.
b) Control of fluid loss
c) Maintenance of system pressure
d) Prevent of pollution entering the system
 Classification of Seals:
1. According to the method of sealing: Positive sealing (prevents leakage) and non-positive
sealing (allows small leakage for lubrication).
2. According to their location in a system: Static seals (used when no movement occurs between
parts) and dynamic seals (used when movement occurs between parts).
3. According to geometric shape of sealing: U-cup ring, Hat ring, T-ring, Quad ring, O-ring, V-ring.
4. According to seal material: Leather seals, Metal seals, Polymers, Elastomers and plastic seals,
Nylon seals etc.
2.12 Filters
 Function of Filters:
a) Remove particles pollutions from fluid.
b) Increase life of system component and fluid.
 Classification of Filters:
1. According to the distance:
i. Surface Filter: It has less thickness and less capacity.
ii. Depth Filter: It has more thickness and more capacity.
2. Full flow filter: All fluid pass through the filter, whether need filtration or not.
3. By-pass filter: Part of fluid passes through the filter, only which need filtration.
 FRL Unit:
 The combination of Filter, Regulator and Lubricator.
 The compressed fluid is first filtered and then pressure regulated and finally lubricated.
2.13 Accumulators & Reservoir
 Accumulators:
 It is a device which stores the potential energy of fluid.
 Types of Accumulator:
1. Gravity or dead weight type
2. Spring loaded type
3. Gas loaded type
i. Non-Separator type
ii. Separator type
a) Piston type
b) Diaphragm type
c) Bag or Bladder type
 Applications of accumulator:
1. Pressure compensation
2. Leakage compensation
3. Emergency source of power

22
 Reservoir:
 It is a device used to store the fluid.
 Functions of Reservoir:
1. Oil storage: It provides sufficient volume to store oil.
2. Heat dissipation from oil: It provides large surface area to dissipate heated oil.
3. Thermal expiation of fluid: It provides extra space to be ready for thermal expansion
of fluid.
4. Separation of various contaminants: It is used Gause baffles to separate contaminants
from oil.
5. Controlling turbulent flow: It is used Baffle plates to control turbulent flow.
Feature of Reservoir
Type of
Accumulator
How do they work Simple pictures
Dead weight
type
 It consists of cylinder housing a piston with packing
inside to prevent leakage.
 The force of gravity of the dead weight is used to
store potential energy.
Spring loaded
type
 It consists of cylinder housing a piston with spring.
 The force of compression spring is used to store
potential energy.
Non-Separator
gas loaded type
 It consists of cylinder having one oil part at the
bottom which contacts with a gas on the top.
 Storage of potential energy is due to compression of
gas.
 The expansion of gas forces the oil out of the
accumulator.
Separator
piston type
 It consists of spherical vessel which has fluid
chamber at the top and separated with air chamber
on the bottom by diaphragm.
 When the oil enters into accumulator, it pushes the
diaphragm and compressed the air.
 This gas pressure is used as the potential energy to
force the oil out when it is required.
Bag or Bladder
type
 It consists of bag or bladder placed inside the
accumulator which has gas and oil which placed
outside the bag.
 When the oil enters into accumulator, it pushes the
bag and compressed the air inside the bag.
 This gas pressure is used as the potential energy to
force the oil out when it is required.

23
2.14 Hydraulic Fluids
 It is used to transmit and control energy in a system.
 Incompressible fluids like oils and water are used in hydraulic systems.
 Function of Hydraulic fluids:
 To transmit power
 To lubricate moving parts
 To seal gaps and cleaning parts
 To dissipate heat causing friction
 To prevent rust and corrosion
 Types of hydraulic fluids:
1. Mineral oils
2. Oil in water
3. Water in oil
4. Water glycol
 Desirable properties of hydraulic fluids:
1. Specific gravity: It is an important property for design of pump, reservoir, piping sizing and for
calculation of pressure at pump inlet.
2. Viscosity: Should have low enough viscosity for lubricate surface and for easy flow ability. Also
having enough viscosity for seal gaps and leakage.
3. Coefficient of thermal expansion: provision in the system design as pipe design, reservoir
design etc.
4. Flammability: Must be non- flammable and should have high flash point and fire point.
5. Gumming tendency: Should have minimum gumming tendency to avoid reduced in flow area.
6. Oxidation tendency: Should have minimum oxidation tendency to avoid changed in oil
characteristics.
7. Corrosion resistance: Should have high corrosion resistance to get longer life of the system.
2.15 Turbines
 Hydro turbine: It converts potential energy of water into mechanical energy or electric energy (AC).
 Classification of Hydro Power Turbines:
1. (Pelton turbine)-(Impulse turbine)-(High head & low quantity of water)-(10 to 35 rpm)
2. (Francis turbine)-(Reaction turbine)-(Medium head & Medium quantity of water)-(60 to
300rpm)
3. (Kaplan turbine)-(Reaction turbine)-(Low head & High quantity of water)-(120 to
1000rpm)
 Wind turbine: It converts kinetic energy of wind into mechanical energy or electric energy (DC).
 Classification of Hydro Power Turbines:
1. Small wind turbines: Less than 12 m in diameter and between 50 W and 50 KW outputs
power.
2. Medium wind turbines: Up to 40 m in diameter and up to 750 KW outputs power.
3. Large wind turbine: : Greater than 40 m in diameter and up to 5 MW outputs power
 Steam turbine: It converts thermal energy of steam into mechanical energy.
 Classification if steam Turbine:
1. Impulse turbine
2. Reaction turbine
3. Combination of Impulse and reaction

24
 Blades of turbine:
1. Fixed blade (nozzle): It converts potential energy of
steam into kinetic energy.
2. Moving blade: It converts that kinetic energy into
mechanical energy.
2.16 Tube and Pipe Requirements
 The piping system in steam power plant is divided into four categories:
1. Steam piping
2. Water piping
3. Blow-off piping
4. Others
 Requirements of steam piping system
1. Maximum reliability
2. Should be of necessary size
3. Withstand high pressure
4. Withstand high temperature and expansion
5. Avoid large number of joints
 Materials for tubes in condenser & feed water heater (FWH)
1. Wrought Iron: used for low and medium pressure range up to 250 psi (17 bar).
2. Alloy Steel: used for high temperature applications.
 Chromium steel pipes used for temperature higher than 525o
C to improves corrosion
resistance.
 Molybdenum steel used for temperature between 400- 525o
C to improves creep
strength.
 Nickel is used to add toughness to the materials.
3. Copper and Brass: used for oil lines, but high in cost. The maximum pressure is limited to
20kg/cm2
.
 Properties of insulation of steam piping
1. Have high insulating efficiency
2. Not affected by moisture
3. Withstand high temperature
4. Have high strength

25
 Types of piping joints: It is used to connect multiple pipes.
1. Threaded Joints: Pipes are connected by screwing with the help
of threads provided for each pipe. One pipe having internal
threads and the other one having external threads. They are
used for Cast iron pipes, copper pipes, PVC and G.I pipes. They
are used in low temperature areas and low pressure flows.
2. Brazed Joints: Jointing pipes using molten filler material at
above 840o
C. They are used for joining copper pipes or copper
alloy pipes. Strength of brazed joint is low compared to other
joints. They are used in moderate range of temperature areas.
3. Soldered Joints: They are similar to brazing but the filler metal
melts at below 840o
C. They are used to joint copper and
copper alloy pipes. They are used for low temperature areas.
They have low strength compared to brazed joints.
4. Welded Joints:
a) Butt Welded Joints: They are used for joining the pipes
that have the same diameter. They are used for large
commercials and industrial piping systems. They have
good strength and they can resist high pressure. They
are expensive and don't opened for maintenance.
b) Socket Welded Joints: They are used when there is a
high chance of leakage in joints. Pipes are connected as
putting one into other and welded around the joint.
They are used when Pipes having different diameters.
They have lower cost than butt welding.
5. Flanged Joints: They are used for high pressure flows and
for large diameter pipes. They are used for plain end pipes
or threaded pipes. Two flange components are connected
by bolts at the pipe joint to prevent leakage. They are made
of cast iron, steel etc. they are having good strength and
resist high pressure. They are also useful for repairing
pipelines and maintenance.

26
6. Compression Joints: When the pipes have plain ends, they
are joined by installing threaded fittings or couplings fittings
at their ends. They can connect pipes of different materials
and different sizes. Compression fittings are available in
different materials and selection of fittings may depend
upon our requirement.
7. Grooved Joints: The pipe ends consist grooved edges which
are connected by elastomer seal and then ductile iron made
grooved couplings are used as lock for elastomer seal. These
grooved couplings are connected by bolts. These joints are
easy to install and economical. They have good resistance
against pressure and they are used in moderate temperature
areas. They are easily removable so, they are easily for
maintenance.

28
3.1 Concept of Heat
 Temperature:
 Temperature is the measure of hotness or coldness of an object.
 A temperature measured in kelvin (K) is called absolute temperature.
 Absolute zero (or 0K) is the temperature at which the pressure of gas becomes zero. 0 K = -
273.15 °C
 Melting Point: The temperature at which a substance changes from solid phase to liquid phase
 Boiling Point: The temperature at which a substance changes from liquid phase to gas phase.
 Light resulting from temperature is called blackbody radiation, and ranges:
Red -1000 K
Orange/Yellow -3000 K
White or light Blue -5000 K
 Types of Flame:
1. Laminar, Premixed: fuel and air are mixed before the combustion. The flow is smooth.
Example: Bunsen burner flame.
2. Laminar, Diffusion: The fuel comes from the wax vapor and air mix after diffusion into
the flame. Example: candle.
3. Turbulent, Premixed: air and fuel are premixed in burner like boiler or furnace.
4. Turbulent, Diffusion: It is the most unwanted fires .no burner or other mechanical
device for mixing fuel and air.
 Combustion Requirements: the combustion required three elements for combustion and if
one of these three elements is removed, the combustion will stop.
1. Fuel
2. Heat (ignition)
3. Air
 Example: Find the equivalent temperature on the indicated scale: (a) –273.15 °C on the
Fahrenheit scale, (b) 98.6°F on the Celsius scale, and (c) 100 K on the Celsius scale and
Fahrenheit scale.
Sol: (a) ∵ 1 8 32
   
F . C ⇒°F = 1.8 X (–273.15) + 32 = – 459.67 ⇒ – 273.15 °C = – 459.67 °F.
S. No. Quantity SI Unit Conventional Unit
Conversion
Formula
Freezing/ Boiling
point of water
1 Temperature kelvin (K)
degree Celsius (°C),
degree Fahrenheit (°F) 32
°C
1.8
°F
273.15
°C
K




Scale Freeze Boil
C 0°C 100°C
K 273K 32°F
F 373K 212°F
2 Heat joule (J) calorie (cal) 1 cal = 4.186 J
3 Pressure pascal (Pa) atmosphere (atm) 1 atm = 10
5
Pa
4 Volume cubic metre (m
3
) litre (l) 1 l = 10
-3
m
3
5 Specific Heat Capacity J/kg.K J/kg.°C, cal/kg.°C
6 Latent Heat J/kg cal/kg

29
(b) ∵ 1 8 32
   
F . C ⇒
32
1 8

 
F -
C
.
⇒
98.6 - 32
°C =
1.8
= 37 ⇒ 98.6°F = 37 °C.
(c) 273 15
  
K C . ⇒ 273 15
 
C K - . ⇒°C =100 - 273.15 = - 173.15 ⇒ 100 K = –173.15 °C.
and 1 8 32
   
F . C ⇒°F = 1.8 X (–173.15) + 32 = – 279.67 ⇒ 100 K = – 279.67 °F.
 Specific Heat or Specific Heat Capacity in Gases, liquids and solids
 It is the energy required to raise the temperature of a unit mass of
a substance by one degree.
 Specific Heat depends on material of the object and doesn't
depend on its mass.
 Specific heat at constant volume "Cv" and specific heat at constant
pressure "Cp"
 Cp is greater than Cv because at constant pressure the system is
allowed to expand and required energy.
 Meyer's Equation: 𝐶𝑝 − 𝐶𝑣 = 𝑅
 Unit:
𝑘𝐽
𝑘𝑔
. °𝐶
 Amount of heat needed to change temperature of an object is
𝑸 = 𝒎 𝑪 ∆𝑻 ,Here, m = mass of object, C = Specific Heat,
T = change in temperature = Tf – Ti
 Example: Calculate the specific heat of copper if 1935 J of heat increases the temperature of
1kg of copper by 5°C.
Sol: Here Q = 1935 J, m= 1kg, T = 5°C. ∵ Q = mCT ⇒ o
Q 1935
C = = = 387 J/kg. C
m ΔT 1X 5
 Heat
 The energy that flows between objects due to their temperature difference is called Heat.
 Each molecule (or atom) of an object has kinetic energy (KE) and potential energy (PE).
 Internal energy (U)of an object is the sum of kinetic energy and potential energy of all the
molecules (or atoms) of the object. 𝑼 = (𝑲𝑬 + 𝑷𝑬)𝒂𝒍𝒍 𝒎𝒐𝒍𝒆𝒄𝒖𝒍𝒆𝒔
 If two objects are in thermal contact but no net flow of heat is between them then they are in
thermal equilibrium  Temperature of the two objects is same.
 If an object takes heat, its internal energy increases; if an object gives heat, its internal
energy decreases.
 If due to transfer of heat the potential energy of the molecules changes by definite amount
then phase of the object changes.
 If due to transfer of heat the kinetic energy of the molecules changes then temperature of
the object changes.
 1 calorie is the heat energy that can raise the temperature of 1g of water by 10
C.
 Principle of Calorimetry: If a cold body is put in thermal contact with a hot body then at thermal
equilibrium.
Heat gained by cold body = Heat lost by hot body.
𝑸𝒄 = −𝑸𝒉
𝒎𝒄𝑪𝒄(𝑻𝑬 − 𝑻𝒄) = −𝒎𝒉𝑪𝒉(𝑻𝑬 − 𝑻𝒉)
Here, mc=mass of cold body, Cc=specific heat of cold body, Tc=temperature of cold body,
mh=mass of hot body, Ch=specific heat of hot body, Th=temperature of hot body and
TE=equilibrium temperature.

30
 Example: Temperature of 0.05 kg of iron is raised to 200 °C and then dropped into a
calorimeter containing 0.35kg of water at 20 °C. If the final temperature is 22.4 °C, find specific
heat capacity of iron.
Sol: Here iron is hot body and water is cold body
⇒ mc = 0.35 kg, Cc = 4186 J/kg.°C, Tc = 20 °C, mh = 0.05 kg, Ch = ?, Th = 200°C and TE = 22.4 °C.
∵ mcCc(TE –Tc)= – mhCh(TE –Th) ⇒
D
o
Q 1935
C = = = 387 J/ kg. C
m T 1X 5
(Ans: 395.97J/kgC)
 Phase Change:
 Change of a solid into liquid (melting), change of a liquid into solid (fusion), change of a liquid
into gas (vaporization), and change of a gas into liquid (condensation) are the instances of
phase change.
Example:
 In a phase change, only the potential energy of the molecules changes (and there is no
change in kinetic energy of the molecules or temperature of the object).
 Latent Heat (L):
 Latent Heat is the amount of heat that changes the phase of 1kg of a substance without
changing its temperature.
 Heat required for phase change is
Where m = mass of the object and L = latent heat of the substance.
 Latent heat of fusion (Lf) is the heat energy associated with melting or fusion.
 Latent heat of vaporization (Lv) is the heat energy associated with boiling or condensation.
Ice Water
+ Qf
– Qf – Qv
+ Qv
Water Steam
Liquid Gas
Q = + mLv
Q = – mLv
Solid Liquid
Q = + mLf
Q = – mLf
If change in temperature ⇒Q = mCT
+ if T = + (when object takes heat)
– if T = – (when object gives heat)
If change in phase ⇒Q = mL
+ if change is from solid to liquid or from liquid to gas
– if change is from liquid to solid or from gas to liquid
Q =  m L

31
3.2 heat Transfer
 Heat transfer
 It is study of thermal energy transfer causing a temperature difference or gradient.
 Energy can transfer from or to a given mass by two mechanisms: heat Q and work W.
 The energy interaction is heat transfer if its driving force is temperature difference, otherwise
it's work.
 A rising piston, a rotating shaft, and an electrical wire crossing are all associated with work
interactions.
 Total Heat transfer (Q): 𝑄 = 𝑚𝐶𝑎𝑣𝑒∆T 𝐽 rate of heat transfer (𝑄̇): 𝑄̇ =
𝑄
∆𝑡
𝐽 𝑠
⁄ 𝑜𝑟 𝑊
 Thermodynamics Vs Heat transfer
Thermodynamics tells about
 How much heat is transferred
 How much work is done
 Final state of the system
Heat transfer tells about
 How heat is transferred
 At what heat is transferred
 Temperature distribution inside the body
 Driving forces
 The driving force for heat transfer is the temperature difference.
 The driving force for electric current flow is the voltage difference.
 The driving force for fluid flow is the pressure difference.
 Energy transfer
 Energy can transferred from or to a given mass by two mechanisms: heat Q and work W .
 The energy interaction is heat transfer if its driving force is a temperature difference,
otherwise it's work
 A rising piston, a rotating shaft, and an electrical wire crossing are all associated with work
interactions.
 Heat Flex
 It is the heat transfer per unit time per unit area.
 𝑞 =
𝑄̇
𝐴
𝑊/𝑚2
 Methods of heat transfer
1. Conduction:
 It is the heat transfer from one substance to another by direct contact.
 Fourier's law of heat conduction:
𝑸
̇ 𝒄𝒐𝒏𝒅𝒖𝒄𝒕𝒊𝒐𝒏 = 𝒌𝑨
𝑻𝟏−𝑻𝟐
∆𝒙
= −𝒌𝑨
∆𝑻
∆𝑨
= −𝒌𝑨
𝒅𝑻
𝒅𝑿
𝑾𝒂𝒕𝒕
 K (Thermal conductivity):
a) It is the rate of heat transfer per unit area per unit temperature difference.
𝑊/𝑚 °𝐶
b) High thermal conductivity means that the substance has good conductor and
vice versa
c) Thermal conductivity of substance depends on the chemical composition,
phase (liquids is more than the gasses and the metals have the highest),
crystalline structure (if solid), temperature (K of the metal decreases when
temperature increased and decreased in fluid), pressure, and homogeneity.
d) Thermal conductivity is affected by the phase change.
 A (Area): Heat transfer increased when the area increases and vice versa.

𝒅𝑻
𝒅𝑿
(Temperature gradient): Heat transfer increased when the temperature gradient
increases.
 ∆𝒙 (Thickness): Heat transfer decreased when the thickness decreases and vice versa.

32
 Thermal diffusivity (𝜶):
a) It is the ratio of thermal conductivity to the heat stored. Heat stored is the
product ρ𝐶𝑝
b) 𝜶 =
𝒌
𝝆𝑪𝒑
, k is thermal conductivity, ρ is the density, and Cp is specific heat.
c) Materials with high thermal conductivity or low heat stored will have large 𝛼.
2. Convection:
 It is the heat transfer within a fluid caused molecular motion or between solid surface
and moving fluid.
 Newton's law of cooling: 𝑸
̇ 𝒄𝒐𝒏𝒗𝒆𝒄𝒕𝒊𝒐𝒏 = 𝒉𝑨𝒔(𝑻𝒔 − 𝑻∞) 𝑾𝒂𝒕𝒕
h is the convection heat transfer coefficient, As is the surface area, Ts is the surface
temperature, 𝑻∞is the temperature of the fluid that far from the surface.
 Forced convection: The fluid forced to flow by external force like a fan, pump, or wind.
 Natural (or free) convection: The fluid motion is caused by temperature difference.
 Internal convection: The fluid flow in a pipe or channel.
 External convection: The fluid flow over a surface.
3. Radiation:
 It is the heat transfer between two substances that are not in contact.
 Stefan-Boltzmann law: the emissivity of blackbody is directly proportional to the fourth
power of absolute temperature.
 𝑸
̇ 𝒓𝒂𝒅𝒊𝒂𝒕𝒊𝒐𝒏 = 𝜺𝝈𝑨𝒔(𝑻𝒔
𝟒
− 𝑻∞
𝟒
) 𝑾𝒂𝒕𝒕 .Stefan-Boltzmann constant 𝝈 = 5.67 ×
10−8
𝑊/𝑚2
𝐾4
,
As is the surface area, Ts is the absolute temperature, 𝜺 is the emissivity.
 Blackbody: The idealized surface that emits radiation at this maximum rate, and the
radiation emitted by a blackbody is called blackbody radiation. For blackbody
𝜺 = 1, 𝛼 = 0, 𝜌 = 0
 Properties of Radiation:
a) Emissivity (𝜺) is the ratio of the radiation emitted by a surface to the
radiation emitted by a blackbody at the same temperature.
b) Absorptivity (𝜶) is the fraction of radiation absorbed by a surface.
𝜶 =
𝑸𝑨𝒃𝒔𝒐𝒓𝒃𝒆𝒅
𝑸𝑰𝒏𝒄𝒊𝒅𝒆𝒏𝒕
c) Reflectivity (𝝆) is the fraction reflected by the surface. 𝜶 =
𝑸𝑹𝒆𝒇𝒍𝒆𝒄𝒕𝒆𝒅
d) Transmissivity (𝝉) is the fraction transmitted by the surface. 𝜶 =
𝑸𝑻𝒓𝒂𝒏𝒔𝒎𝒊𝒕𝒕𝒆𝒅
𝜶 + 𝝆 + 𝝉 = 𝟏
 The Kirchhoff's law of radiation: The emissivity and the absorptivity of a surface are
equal at the same temperature and wavelength. 𝜺𝟏 = 𝜶𝟏; 𝜺𝟐 = 𝜶𝟐 … …
 Heat generation
 It is conversion of electrical, nuclear, or chemical energy into heat or thermal energy.
 𝑮̇ = 𝒈̇ 𝑽 𝒐𝒓 𝑰𝑽 𝑾𝒂𝒕𝒕, 𝒈̇ is the constant rate of heat generation per unit volume
(W/m3
), V is the volume, 𝐈 is the current, and V is the voltage.

34
4.1 Newton's Laws – Kinematics – Kinetics
 Mechanics of Machines: It's study of motion and forces between various parts of a machine.
 Machine: It's a device which receives energy from some sources and uses it to do some useful
work
 Sub-divisions of mechanics of machines:
a) Kinematics: It studies of motion between various parts of a machine without studies of force.
b) Dynamics: It studies of forces of the moving parts of machines.
c) Kinetics: It studies of inertia forces come from both mass and motion of moving parts of
machines.
d) Statics: It studies of forces of the rest parts of machines.
Basics of SI units: Prefixes used in SI units some conversion of units
 Newton's Laws of motion:
 Newton's first law: everybody continuous of rest or motion until acted by external force.
 Newton's second law: The rate of change in momentum (Force) is directly proportional to the
acceleration. 𝐹 = (𝑚𝑣 − 𝑚𝑢) 𝑡
⁄ = 𝑚(𝑣 − 𝑢 𝑡
⁄ ) = 𝑚𝑎
 Newton's third law: To every action there is always an equal and opposite reaction.
 Plane motion: The motion of body moves to only one plane.
 Types of plane motion:
1. Rectilinear motion: When a body is moving in straight line path.
2. Curvilinear motion: When a body is moving along curved path.
 Linear velocity: It is the rate of change of linear displacement to the time. 𝑣 =
𝑑𝑠
𝑑𝑡
𝑚/𝑠
 Linear Acceleration: It is the rate of change of linear velocity to the time. 𝑎 =
𝑑𝑣
𝑑𝑡
=
𝑑2𝑠
𝑑𝑡2 𝑚/𝑠2
 Equation of linear motion:
 𝑣 = 𝑢 + 𝑎𝑡
 𝑠 = 𝑢𝑡 + 1
2
⁄ 𝑎𝑡2
 𝑣2
= 𝑢2
+ 2𝑎𝑠
 𝑠 = ((𝑢 + 𝑣)𝑡)) ⁄ (2) = 𝑣𝑎𝑣𝑡
v Velocity m/s
a Acceleration m/s
2
s Displacement m
ω Angular velocity Rad/s
∝ Angular acceleration Rad/s
2
θ Angular displacement rad
ρ Density Kg/m
3
F,W Force, weight Kg.m/s
2
or N
p Pressure N/m
2
or Pa
W,E,
M, T
Work, Energy, Moment
of Force, Torque
N.m or J
P Power J/s or Watt
M Mass kg
P Momentum Kg.m/s
Ι Moment of Inertia Kg.m
2
𝜚 Electric charge coulomb (C)
V Electric Voltage volt (v)
I Electric Current ampere (A)
R Electric Resistance Ohm (Ω)
C Electric Capacitance farad (F)
B Magnetic field tesla (T)
L Inductance henry (H)
ʄ Frequency Hertz (Hz)
Power Prefix symbol
10
-24
yocto y
10
-21
zepto z
10
-18
atto a
10
-15
femto f
10
-12
pico- P
10
-9
nano- N
10
-6
micro- Μ
10
-3
milli- M
10
-2
centi- C
10
-1
deci- D
10
1
deka- da
10
3
kilo- K
10
6
mega- M
10
9
giga- G
10
12
tera- T
10
15
peta P
10
18
exa E
10
21
zetta Z
10
24
yotto Y
1 kg 2.2 Pounds
1 kg 35.27 Ounces
1 foot 30.5 cm
1 foot 12 inch
1 inch 2.54 cm
1 mile 1.61 Km
1 calories 1.026 Pound
1 knot 6068 feet
1 league 3 knot
1 yard 36 inch
1 yard 3 feet
1 decimeter 10 cm
1 gallon 3.8 liters
1 oil barrels 42 gallons
1 fluid barrels 31.5 gallons
1 tons 1000 kg
1 tons 7.3 oil barrels
1 acre 4200 m
2
1 hectare 100,000 m
2
1 century 10 years

35
 Angular velocity: It is the rate of change of angular displacement to the time. 𝜔 =
𝑑𝜃
𝑑𝑡
𝑟𝑎𝑑 𝑠
⁄
 Angular acceleration: It is the rate of change of linear velocity to the time. 𝛼 =
𝑑𝜔
𝑑𝑡
=
𝑑2𝜃
𝑑𝑡2 𝑟𝑎𝑑/𝑠2
 Equation of angular motion:
 𝜔 = 𝜔0 + 𝛼𝑡
 𝜃 = 𝜔0𝑡 + 1
2
⁄ 𝛼𝑡2
 𝜔2
= 𝜔0
2
+ 2𝛼𝜃
 𝜃 = ((𝜔0 + 𝜔)𝑡)) ⁄ (2) = 𝜔𝑎𝑣𝑡
 If a body is rotating at the speed of N r.p.m. (revolutions per minute), then 𝜔 = 2𝜋𝑁 60 𝑟𝑎𝑑/𝑠
⁄
 Relationship between Linear and Angular motion:
 Linear velocity: 𝑣 = 𝑟. 𝜔 𝑚/𝑠
 Linear acceleration: 𝑎 = 𝑟. 𝛼 𝑚/𝑠2
 Acceleration of a particle along a circular path: When a particle moves along a circular path, it has two
components of acceleration.
1. Tangential component: 𝑎𝑡 = 𝑟. 𝛼 𝑚/𝑠2
2. Normal component: 𝑎𝑛 = 𝜔2
. 𝑟 𝑚/𝑠2
Total acceleration: 𝑎 = √(𝑎𝑡
2
+ 𝑎𝑛
2)
Inclination between acceleration: 𝑡𝑎𝑛𝜃 = 𝑎𝑛 𝑎𝑡
⁄
 Oscillatory motion of a particle:
 Simple Harmonic Motion (S.H.M): It is a to and fro motion. In S.H.M, the acceleration
is directly proportional to its distance. Ex of S.H.M: oscillations of a pendulum,
motion of piston in an engine cylinder.
 Oscillation: a body moves to and fro motion from mean position to one end position,
then to the other end position and back to the mean position.
 Amplitude: Maximum displacement of the body from its mean position.
 Time Period: Time taken to complete one oscillation. 𝑻 = 𝟐𝝅/𝝎
 Frequency: Number of oscillations per second. 𝒇 =
𝟏
𝑻
 Mass: It is the amount of matter contained in a body. It doesn’t change when positions change.
 Weight: It is the product of mass & gravity acceleration. It changes when positions change. 𝑊 = 𝑚𝑔 𝑁
 Momentum: it is the product of mass and velocity of a body. 𝑀𝑜𝑚𝑒𝑛𝑡𝑢𝑚 = 𝑚𝑣 𝑘𝑔.
𝑚
𝑠
 Law of conservation of momentum: Total momentum remains same if no external force acts.
Initial momentum = final momentum 𝑚1𝑢1 + 𝑚2𝑢2 + ⋯ = 𝑚1𝑣1 + 𝑚2𝑣2 + ⋯
 Impulse: It is the product of force and time. Impulse = 𝐹𝑡 𝑜𝑟 𝑚∆𝑣 𝑁. 𝑠
 Force: It is the rate of change in momentum. 𝐹 = 𝑚𝑎 𝑘𝑔. 𝑚/𝑠2
 Concurrent force: Two or more forces are action intersect at the same point. Ex: Pull Rope
 Non-concurrent force: Two or more forces have equal magnitudes, but act in opposite
direction. Ex: Couple.
 Moment of Force: It is the product of force and perpendicular distance. 𝑀 = 𝐹 × 𝐿 𝑁. 𝑚 𝑜𝑟 𝐽
 Couple: Two equal and opposite forces form a couple. 𝑴𝒐𝒎𝒆𝒏𝒕 𝒐𝒇 𝒄𝒐𝒖𝒑𝒍𝒆 = 𝐹 × 𝑋
 Centripetal and Centrifugal Forces: If a particle moves in a circular path, there are two forces keeping
the particle in path.
1. Centrifugal force acts outwards:𝐹 = 𝑚𝜔2
𝑟 , r = radius, m = mass, ω = angular velocity

36
2. Centripetal force acts inwards: 𝐹 = 𝑚
𝑣2
𝑟
,
𝑣2
𝑟
= centripetal acceleration
 Moment of Inertia: It is the product of mass & square of the perpendicular distance. 𝐼 = 𝑚𝑘2
𝑘𝑔. 𝑚2
k=radius of gyration
 Torque: It is the moment of force. It is the product of force and perpendicular distance.
𝑇 = 𝐹. 𝑟 𝑁. 𝑚 𝑜𝑟 𝐽 For rotation bodies: 𝑇 = 𝐼. 𝛼 𝑁. 𝑚 𝑜𝑟 𝐽
 Work: It is the product of force and displacement.
𝑊 = 𝐹. 𝑋 𝑁. 𝑚 𝑜𝑟 𝐽 For rotation bodies: 𝑊 = 𝑇. 𝜃 𝑁. 𝑚 𝑜𝑟 𝐽
 Work done on moving a body is equal to its change in Kinetic Energy (∆K.E).
 Work done on lifting a body is equal to its change in Potential Energy (∆P.E).
 Power: It is the rate of doing work or work done per unit time.
𝑃 =
𝑊𝑜𝑟𝑘 𝑑𝑜𝑛𝑒
𝑡𝑖𝑚𝑒
=
𝑊
𝑡
𝐽 𝑠
⁄ 𝑜𝑟 𝑊𝑎𝑡𝑡 (1 hp=746 W), For rotation bodies: 𝑃 = 𝑇. 𝜔 𝐽 𝑠
⁄ 𝑜𝑟 𝑊𝑎𝑡𝑡
 Energy: It is the capacity to do work. There are different forms of energy like mechanical energy,
electrical energy, chemical energy, heat energy, light energy, wind energy, etc.
 Law of energy conservation: Total energy in the universe is constant. 𝐾𝐸 + 𝑃𝐸 = 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡
Or energy cannot be created or destroyed but it can be converted from one form to other.
 Potential Energy: It is the energy due to the position of the body. 𝑃. 𝐸 = 𝑚𝑔ℎ 𝑁. 𝑚 𝑜𝑟 𝐽
 Strain Energy: It is the energy due to deformed of the body.
𝑆. 𝐸 = 1
2
⁄ 𝑆𝑋2
𝑁. 𝑚 𝑜𝑟 𝐽 , S=Stiffness in N/m, x= distance in m
 Kinetic Energy: It is the energy due to motion of the body.
𝐾. 𝐸 = 1
2
⁄ 𝑚𝑣2
𝑁. 𝑚 𝑜𝑟 𝐽 For rotation bodies: 𝐾. 𝐸 = 1
2
⁄ 𝐼𝜔2
𝑁. 𝑚 𝑜𝑟 𝐽
 Efficiency of a Machine: It is the ratio of output power to the input power. ƞ =
𝑂𝑢𝑡𝑝𝑢𝑡
𝐼𝑛𝑝𝑢𝑡
𝑁𝑜 𝑢𝑛𝑖𝑡
4.2 Concepts of Mechanisms
 Machines are devices which use energy to do some useful work.
 Machines are made using parts or bodies or links.
 Machines use mechanisms to get the required motion.
 Kinematic Link or Element: It is a part of machine which has relative motion and resistant body.
 Resistant body: It is transmission the required motion with negligible deformation.
 Types of Links:
1. Rigid Link: It is a link or a body which can transmit motion with no deformation. Ex: Connecting
rod or Crank.
2. Flexible Link: It is a link or a body which can transmit motion with partly deformation. Ex: Belt,
Rope, Chain.
3. Fluid Link: The transmission of motion takes place though fluid under pressure. Ex: Hydraulic
presses, Jacks and Brakes.
 Structure: It is an arrangement of group of resistant bodies having no relative motion between them.
Ex: Railway, Bridge, machine frame.
 Difference between Machine and Structure:
Machine Structure
 Parts move relative to another  Parts don’t move relative to another
 Transfer energy into useful work  Doesn't Transfer energy into useful work
 Links transmit both power and motion  Links transmit forces only

37
 Kinematic Pair: The motion between two links or elements that contact with each other is completely
constrained or successfully constrained.
 Types of constrained motions:
1. Completely constrained motion: The motion between pair is limited to one direction.
Ex: Square bar in a square hole.
2. Incompletely constrained motion: The motion between pair can take place in more than
one direction. Ex: Shaft in a circular hole.
3. Successfully constrained motion: The motion between pair is not completed by itself, but
by external force. Ex: Foot step bearing.
 Classification of kinematic pairs:
1. According to the type of relative motion between the elements:
a) Sliding pair: When two elements of pair are connected and one slides to other
fixed link. Ex: Piston and cylinder.
b) Turning pair: When two elements of pair are connected and one turns about
other fixed link. Ex: shaft fitted into a circular hole.
c) Rolling pair: When two elements of pair are connected and one rolls over other
fixed link. Ex: Ball and roller bearing.
d) Screw pair: When two elements of pair are connected and one turns about other
link by screw threads. Ex: bolt and nut.
e) Spherical pair: When two elements of pair are connected and one turns about
other fixed link. Ex: attachment of car mirror, Ball and socket joint.
2. According to the type of contact between the elements:
a) Lower pair: When two elements of pair have a surface contact and motion
between them is turning or sliding. Ex: Sliding pairs, Turning pairs and Screw pairs.
b) Higher pair: When two elements of pair have a point or line contact and motion
between them is partly turning and partly sliding. Ex: Toothed gearing, belt and
rope drives.
3. According to the type of closure:
a) Self-closed pair: When two elements of pair are connected together
mechanically. Ex: Lower pair.
b) Forced closed pair: When two elements of pair not connected together
mechanically, but they are kept in contact by external forces. Ex: Cam & Follower.
 Kinematic Chain: Kinematic pairs are joined that last link is joined to the first link to transmit motion.
 Types of joints:
1. Binary joint: If two links are jointed at the same point.
2. Ternary joint: If three links are jointed at the same point.
3. Quaternary joint: If four links are jointed at the same point.
 Mechanism: In a kinematic chain, if one of the links is fixed. Ex: Engine indicators, typewriter.
 Types of mechanism:
1. Simple mechanism: If the mechanism has only four links.
2. Compound mechanism: If the mechanism has more than four links.

38
4.3 Computer Simulation of Mechanisms
 It is creating a mechanism model in the computer to see how it works by changing different parameters.
 Advantages of computer simulation of mechanisms:
 Easy and quick to make models and test in computers.
 Low cost compared to actual testing.
 Problems complex can be analyzed before making the real mechanisms.
 Steps of computer simulation of mechanisms:
1. Creating the model of different parts of the mechanisms
2. Assembling the parts
3. Applying the parameters to different parts
4. Running the model
5. Observing the results of working of mechanisms
6. If the mechanism doesn’t work, change the parameters and check until it works.
7. Use the data for making the real time mechanisms
 Common software used for computer simulation of mechanisms:
1. ADAMS - Automatic Dynamic Analysis of Mechanical System
2. ANSYS – Analysis of System
3. Pro-Engineer
4. CATIA – Computer Aided Three-Dimensional Interactive Application
5. UG – Unigraphics
6. Autodesk – Inventor
4.4 Balancing of Rotating and Reciprocating Masses
 Balancing is the process of designing a machine in which unbalance force is minimum.
 Machines and Engines have moving elements or parts. Some of them are rotating and some
of them are reciprocating. These parts should be balanced. If the parts in a machine are not
balanced, unbalanced forces setup in the machine and they increase the loads on machine
parts and also create stresses and vibrations in the machine parts.
 Balancing of Rotating Masses:
 When any the part is rotating, it produced centrifugal force. If this centrifugal force is
unbalanced then it bends the parts of the machine. To balance this unbalanced centrifugal
force, a mass is attached opposite side of the part to balance the centrifugal force.
 Balancing of Reciprocating Masses:
 There are various forces acting on the reciprocating parts of an engine. The resultant of all
the forces is known as unbalanced force or shaking force. If the resultant is zero, then there
is no unbalanced force. And if the resultant increased, then the unbalanced force will
increase.
4.5 Cams and Followers
 There are several machine elements used to transmit the power from one part to other.
Ex: gears, belts, cams, chains etc.
 Cams: It is a component of machine that is used to transmit motion to another
component called follower. It is used to transform a rotary motion into a translating or
oscillating motion.
 A cam mechanism consists of three elements: the cam, the follower and the frame.

39
 Applications of Cams:
1. Opening and closing of valves in IC engines
2. Paper cutting machinery
3. Making clothes machinery (Textile machinery)
4. Automatic lath machine
5. Printing presses
6. Food processing machinery
 Classification of followers
1. According to the surface of contact
a) Knife Edge Follower: If the contacting end of the follower is
knife edge. It is used in applications where low force is
applied on follower and cam rotates with low speeds.
b) Roller follower: If the contacting end of the follower is
roller. It is used in stationary gas engines and aircraft
engines where high force on follower and high speed of
cam.
c) Flat faced follower: If the contacting end of the follower is
flat face. It is used in automobile IC engines where medium
force is applied on follower and cam rotates with medium
speeds.
d) Spherical faced follower: If the contacting end of the
follower is spherical shape. It is used in automobile engines
where medium force is applied on follower and cam
rotates with medium speeds. The flat end of the follower is
machined to a spherical shape reduced surface stresses.
2. According to the motion of follower
a) Reciprocating or translating follower: when the
uniform rotary motion of the cam is converted into
reciprocating motion of the follower.
b) Oscillating or rotating follower: when the uniform
rotary motion of the cam is converted into oscillating
motion of the follower.

40
3. According to the path of motion of the follower
a) Radial follower: When the motion of the follower is passing
through the axis of the cam center.
b) Offset follower: When the motion of the follower is
passing away from the axis of the cam center.
 Classification of Cams:
1. Radial Cam or Disc Cam: The reciprocating or oscillating follower is
perpendicular to the cam axis.
2. Cylindrical Cam: The reciprocating or oscillating follower is
parallel to the cam axis.
 Motion of follower
1. Uniform velocity
2. Simple harmonic motion
3. Uniform acceleration and retardation
4. Cycloidal motion
4.6 Gears Drives
 They are mechanical elements that are used to transmit the power from one shaft to another.
 Types of Gears
1. Spur Gears: The teeth of the gear are cut parallel to the axis of the
wheel. They are used to transmit power when shafts are parallel.
2. Helical Gears: The teeth of the gear are cut inclined to the axis of the
wheel. They are used to transmit power when shafts are parallel. They
have more contact area compared to spur gears, so they run smoothly
with less noise.
3. Herringbone Gears (Double helical gears): The teeth of the gear are
cut inclined to the axis of the wheel in two sides. They are used to
transmit power when shafts are parallel. They are used to reduce
thrust force on gear shafts.

41
4. Bevel Spur Gears: Wheel is made in bevel shape and the teeth of the
gear are cut around the bevel surface of the wheel. . They are used to
transmit power when the angle between shafts is 90°.
5. Bevel Helical Gears: Wheel is made in bevel shape and the teeth of
the gear are cut inclined around the bevel surface of the wheel. They
have more contact area compared to the bevel gears, so they run
smoothly with less noise. They are used to transmit power when the
angle between shafts is 90°.
6. Worm Gears: the teeth of the gear are cut in spiral shape around the
wheel. They are used to transmit power when the angle between
shafts is 90°and high reductions in velocities are required.
7. Rack and Pinion: If the teeth are cut on straight surface it is called
Rack. If the teeth are cut on circular surface it is called Pinion. The
combination is called Rack and Pinion. They are used to convert
the rotary motion into reciprocating motion and vice versa.
 Advantages of gear drives:
 They can transmit large powers
 They can transmit exact velocity ratios
 They have reliable service
 Disadvantages of gear drives
 Manufacturing of gears required special tools and equipment
 Errors in cutting teeth cause vibrations
 Simple Gear Train
 There is only one gear on each shaft.
 Speed of gear is inversely proportional to the number of teeth.
 Speed ratio: Speed of the driver to the driven.
N1
N2
=
T2
T1
 Train value: Speed of the driven to the driver.
N2
N1
=
T1
T2
N1= Speed of the driver in rpm
N2= Speed of the driven in rpm
T1= Number of the teeth on gear 1
T1= Number of the teeth on gear 2

42
 Compound Gear Train
 There is more than one gear on each shaft.
 They are used when speed changes are required
between two shafts.
 Speed ratio =
Speed of the first driver
Speed of the last driver
=
Product of the number of teeth on the drivens
Product of the number of teeth on the drivers
=
N1
N6
=
T2 × T4 × T6
T1 × T3 × T5
 Train value: Speed of the last driven to the first driver.
N6
N1
=
T1 × T3 × T5
T2 × T4 × T6
 Epicyclic Gear Train
 They are used to transmit high velocity ratios with less space.
 They are used in Lathes, differential gears of automobiles, wrist
watches etc.
 It has gear A, gear B and arm C. If the arm C is fixed, it acts like a
simple gear train.
 If the gear A is fixed, then the arm and gear B can rotate clockwise
or anticlockwise around the gear A, it is called Epicyclic motion.
 Table of Motions:
Step
No.
Condition of motion Revolution of elements
Arm C Gear A Gear B
1.
2.
3.
4.
Arm fixed, Gear A rotates +1 rev anticlockwise
Arm fixed, Gear A rotates +1 rev anticlockwise
Add +y rev to all elements
Total motion
0
0
+𝑦
+𝑦
+1
+𝑥
+𝑦
𝑥 + 𝑦
−
𝑇𝐴
𝑇𝐵
−𝑥
𝑇𝐴
𝑇𝐵
+𝑦
𝑦 − 𝑥
𝑇𝐴
𝑇𝐵
4.7 Belt Drives
 It is a loop of flexible material used to link two of rotating shafts for transmission of motion or
power.
 Selection of a belt drive: It depends upon the following factors:
1. Speed of driving and driving shafts
2. Speed reduction ratio
3. Power to be transmitted
4. Positive drive requirements
5. Shafts layout
 Types of belt drives
1. According to the speed of belt drives
a) Light drives: They are used to transmit small powers at belt speeds up to
about 10 m/s. Ex: in agricultural machine and small machine tools.
b) Medium drives: They are used to transmit medium powers at belt speeds
between 10 m/s and 22 m/s. Ex: in machine tools
c) Heavy drives: They are used to transmit large powers at belt speeds above
22 m/s. Ex: in compressor and generators.

43
2. According to the shape of cross section of belt drives
a) Flat belt: The cross section of the belt is like
rectangular shape. They are used to transmit medium
power where distance between pulleys is medium.
b) V-belt: The cross section of the belt is like V-shape.
They are used to transmit medium power where
pulleys are very near to each other.
c) Rope: The cross section of the belt is like circular
shape. They are used to transmit large power where
pulleys are far to each other.
3. According to the construction and working
a) Open belt drive: It is used when
shafts are arranged in parallel and
rotating in the same direction.
The tension is more in the lower
side (tight side) and less in the
upper side (slack side).
b) Crossed belt drive: It is used
when shafts are arranged in
parallel and rotating in opposite
direction.
c) Belt drive with idler pulleys: Idler
pulleys are used to increase the
contact angle on the smaller
pulleys. It is used to obtain high
velocity ratios.
d) Compound belt drive: It is used to
increase or decrease the driven
shaft speed.

44
e) Stepped or cone pulley drive: It is used to
change the speed of the driven shaft when
driving shaft runs at constant speed.
f) Loose and Fast pulley drive: They put on
the driven shaft to stop it whenever it is
required.
 Velocity ratio of belt drives:
 Velocity ratio: Speed of the driven to the driver.
N2
N1
=
d1
d2
 When the thickness (t) of the belt is considered: Velocity ratio:
N2
N1
=
d1+𝑡
d2+𝑡
d1=diameter of the driver
d2=diameter of the driven
N1=speed of the driver
N2=speed of the driven
 Velocity ratio of a compound belt:
Speed of the last driven
Speed of the first driver
=
Product of the diameters on the drivens
Product of the diameters on the drivers
N4
N1
=
d1 × d2
d2 × d4
 Slip of belt: The pulley moves without carrying belt with it because the frictional grip between belt and
pulley is insufficient. It is considered in percentages. If the percentage of slip is "s", then
Velocity ratio:
N2
N1
= d1 d2(1 − (𝑠 100
⁄ ))
⁄
 Power transmitted by a belt:
𝑃 = (𝑇1 − 𝑇2). 𝑣 𝑊𝑎𝑡𝑡
T1= Tension in the tight side of the belt
T2= Tension in the slack side of the belt
v= Velocity of the belt in m/s
 Materials used for Belts: Leather, Fabric (Cotton),Rubber fabric combination,Balata fabric combination
4.8 Wire Ropes
 They are used to transmit power from one pulley to another
when the distance between pulleys is long (up to 150m apart)
 They are used in elevators, mine hoists, cranes, conveyors,
handling devices and suspension bridges
 They are made from cold drawn wires in order to have high
strength and durability of the rope.
 They are made from wrought iron, cast steel and alloy steel.
 The core made from jute, asbestos or a wire of softer steel.

45
 Advantages of wire ropes
1. Withstand shock loads
2. Have more durable
3. Have silent operation
4. Have high efficiency
5. Have more reliable
 Designation of wire ropes
Standard designation (No. of strand × No. of wire) Application
6×7 rope It is used as rope in mines, tramways and power
transmission.
6×19 rope It is used in mine hoists, quarries, cranes, dredges,
elevators, tram ways etc.
6×37 rope It is used in steel mill ladles, cranes and high speed
elevators.
8×19 rope It is used in hoisting rope.
 Procedure for designing a wire rope
1. Selection of rope from the table (Example: 6×7)
2. Find the design load
3. Find the rope diameter
4. Find the wire diameter and rope area
5. Find the various stresses acting in the rope
6. Find the effective loads on the rope during normal working, during starting and during
acceleration of the load.
7. Find the actual factor of safety (FOS) and compare with the factor assumed initially. If the
actual factor of safety is within permissible limits, then the design is safe.
 Failure of wire ropes: It is due to fatigue adhesive and wear.
4.9 Breaks
 It is a device used to bring a moving system to rest, to slow its speed, or to control its speed.
 The function of a break is to turn mechanical energy into heat.
 Types of breaks
1. Hydraulic breaks
2. Electric breaks
3. Mechanical breaks
 Type of mechanical brakes according to the direction of action force:
a) Radial brakes: The force acting on the brake drum is in radial direction.
They are divided into external brakes and internal brakes.
b) Axial brakes: The force acting on the brake drum is in axial direction. They
are divided into disc brakes and cone brakes.
 The hydraulic and electric brakes cannot bring the system to rest, and they are used
where large amounts of energy are to be transformed.
 Characteristics of brake materials
1. Have high coefficient of friction
2. Have low wear rate
3. Have high heat resistance
4. Have high heat dissipation capacity
5. Have low coefficient of thermal expansion
6. Have enough mechanical strength
7. Not affected by moisture and oil

46
 Single block or shoe brake
 It consists of a block or shoe witch is pressed against
the wheel by a force applied to one end and other
end is fixed.
 The block is made of a softer material than the rim
of a wheel.
 It is used on railway trains and tram cars.
 The friction between the block and the wheel causes a tangential braking force, which delay
the motion of the wheel.
 Self-energizing brakes: The frictional force helps to apply the brake.
 Self-locking brake: The frictional force is great enough to apply the brake with no external
force.
 Pivoted block or shoe brake
 It consists of a pivoted block or shoe witch is
pressed against the wheel by a force applied to one
end and other end is fixed.
 The angle of contact is greater than 60°, then the
pressure of contact between the block and wheel is
less at the ends than at the center.
 Double block or shoe brake
 It consists of two blocks or shoes applied at opposite ends
of the wheel.
 It is used to overcome bending of the shaft that produced
in the single block brake caused additional load is applied
on the shaft bearings due to normal force (RN).
 It is used in electric cranes.
4.10 Clutches
 They are a machine member used to connect a driving shaft to a driven shaft so that the
driven shaft maybe started or stopped without stopping the driving shaft (engine).
 They are used in automobiles.
 Types of clutches
1. Positive clutches: They are used when a positive drive is required.
a) Positive jaw clutch: It allows one shaft to drive another through a direct
contact of interlocking jaws.
 Types of friction clutches
i. Square jaw clutch: It is used where engagement and
disengagement in motion is not necessary. It transmits power
in either direction of rotation.
ii. Spiral jaw clutch: It is used where engagement and
disengagement in motion is necessary. It transmits power in
one direction only.

47
b) Friction clutches: They are used to transmit power of shafts and machines
which must be started and stopped frequently. In automobiles, friction clutch
is used to connect the engine to the drive shaft.
.
 Characteristics of brake materials
i. Have high coefficient of friction
ii. have high heat conductivity
iii. Have high heat resistance
iv. Not affected by moisture and oil
 Types of friction clutches
1. Disc or plate clutches
a) Single disc or plate clutch: It is a dry clutch. It is
used in applications where large space is available,
such as trucks and cars.
b) Multiple disc or plate clutch: It is a wet clutches. It
is used in applications where small space is
available, such as scooter and motorbike.
 Dry and wet clutches
i. Dry clutch has a higher coefficient of
fraction than wet clutch.
ii. Dry clutch has a higher torque capacity
than wet clutches.
iii. Heat dissipation is more difficult in dry
clutch than wet clutch.
iv. Rate of wear is less in wet clutch than dry
clutch.
2. Cone clutches: They was used in automobiles, but now a
day it has been replaced by the disc clutch.
3. Centrifugal clutches: It uses a centrifugal force to connect
driving shaft to the driven shaft. It works more at higher
speeds. It is used in lawn mowers, chainsaws, mini bikes,
and boats.

49
Thermodynamics 1
5.1
 It is the science of energy. It is the study of energy.
 Mass (m): The amount of material present in body. SI unit Kg
 Weight (W): the force produced when the mass of body is accelerated by gravitational acceleration. SI
unit N or Kg.m/s2
. The mass remain constant even if gravitational acceleration changes.
 Specific volume(v): It is the Volume per unit mass, SI unit m3
/kg
 Density (P): It is the mass per unit volume, SI unit kg/m3
 Specific Gravity (S.G): Compared density of substance to the density water at standard temperature
(1 g/cm3
).
 Temperature (T): It is a measure of degree of hotness and coldness of the substance. Absolute
temperature scale has only positive values.
Celsius (C) Fahrenheit (F) Kelvin (K) Rankine (R)
 scales has 100 units
 Freezing point of water is 0
o
C
 Boiling point of water is
100
o
C
 Eq:
o
C =(
o
F- 32)(5/9)
 Scales has 180 units
 Freezing point of water is 0
o
F
 Boiling point of water is 212
o
F
 Eq:
o
F = 32+(9/5)
o
C
 The absolute
temperature scale
that corresponds
to Celsius scale.
 Eq:
o
K =
o
C+273
 The absolute
temperature scale
that corresponds to
Fahrenheit scale.
 Eq:
o
R =
o
F+273
 Pressure (P): it is the force per unit area. SI unit N/m2
or Pa. The pressure is measured relative to
perfect vacuum called absolute pressure. The pressure is measured relative to atmospheric called
gauge pressure, and it will be zero when open to the atmosphere. A perfect vacuum if absolute
pressure is zero.
Eq: Pabs = Patm + Pgauge
Pabs = Patm + Pvac
 Energy (E): the capacity for doing work.
a) Total Energy (E): sum of kinetic, potential, electrical, magnetic, chemical and nuclear energies.
b) Potential Energy (PE): the energy produced by the body during its position.
c) Kinetic Energy (KE):the energy produced by the body during its motion.
d) Microscopic Energy: The form of energy related to molecular structure of a system.
e) Internal Energy (U): The sum of all microscopic forms of energy. It represents the microscopic
energy of a non-flowing fluid, but enthalpy (h) represents the microscopic energy of a flowing
fluid.
i. Sensible energy or heat: The internal energy associated with the sum of kinetic and
potential energy of the molecules.
ii. Latent energy or heat: The internal energy associated with the phase of a system.
iii. Chemical or bond Energy: The internal energy associated with the atomic bonds in a
molecule.
iv. Nuclear Energy: The internal energy associated with the nucleus of the atom itself.
 Thermodynamic System and Surrounding
 System is a quantity of matter in space.
 Surrounding is everything external to the system.
 Boundary is separated the system and surrounding.
 System and its surrounding together make a universe.
 Types of thermodynamic systems:
 Isolated system: neither energy (work or heat) nor mass transfer with its surrounding.
 Closed system: No mass transfer, but have energy transfer with its surrounding.
 Open system: Both energy and mass transfer with its surrounding.

50
 Energy interactions: closed system and its surrounding can interact in two ways:
1. Work transfer: because changes in properties.
2. Heat transfer: because of temperature difference
 Thermodynamic Equilibrium: state of rest or balanced.
 Types of Equilibrium:
a) Mechanical equilibrium: There is no pressure difference.
b) Thermal equilibrium: There is no temperature difference.
c) Chemical equilibrium: There is no chemical reactions occur.
d) Thermodynamic equilibrium: If all three equilibriums are present.
 Thermodynamic Process: The path of states when the system passes.
 Cycle process: system and surrounding return to their original condition in the final process.
 Reversible process: system and surrounding return to their original condition when stop the
process.
 Irreversible process: system and surrounding can't return to their original condition.
 Lows of thermodynamics:
 First Law of thermodynamic: Energy can't be created nor destroyed, but it can convert from
one form to another.
 Second Law of thermodynamics: the total entropy of an isolated system always increases over
time, or remains constant. Or if no energy enters or leaves the system (isolated system), the
potential energy of the state will always be less than that of the initial state.
 Zeroth Law of thermodynamics: if two systems, A and B, are in thermal equilibrium with a
third system, C, then A and B are in thermal equilibrium with each other.
 Heat engines: the device that converts heat into work.
 How heat engine work:
1. Receives heat from a source at higher temperature.
2. Converts a part of heat into work.
3. Reject other part of heat to balance at lower
temperature.
4. Continues to repeat the same cycle.
 Petrol engine, Diesel engine, Steam power plant, etc are forms of heat engines.
 Thermal efficiency of heat engine: it is the measuring of performance of heat engine.
Ƞth =
Net Workdone
𝐻𝑒𝑎𝑡 𝑆𝑢𝑝𝑝𝑙𝑖𝑒𝑑
=
𝑊𝑛𝑒𝑡
𝑄𝐻
=
𝑄𝐻−𝑄𝐿
𝑄𝐻
= 1 − [
𝑄𝐿
𝑄𝐻
]
5.2 Thermodynamics 2
 Ideal and Real Gas:
1. Ideal gas: it is one which
 Attraction between molecules is zero.
 The size of molecules is zero.
 Doesn’t change its phase during thermodynamic process.
 Obey all gas laws.
2. Real gas: Opposite to ideal gas.
 Gas Laws:
 Boyles Law: Pressure is inversely proportional to Volume when Temperature is constant. Pv=C
 Charles Law: Volume is directly proportional to temperature when pressure is constant.
𝑉
𝑇
= 𝐶

51
 Guy Lassac's Law: Pressure is directly proportional to temperature when volume is constant.
𝑃
𝑇
= 𝐶
 Avogadro's Law: the volume of 1 kg, mole of all gases at normal temperature & pressure is the same
and it is equal to 22.4 m3
.
𝑛 =
𝑚
𝑀
m=mass; M=molecular weight; n=number of moles
 Idea gas equation of state:
PV=mRT Universal Gas Constant (Ru): 8.314 KJ/Kmol.o
K
Classification of Air Cycle
 Ideal Cycles and Actual Engines:
Ideal Cycle:
 Processes are Totally Reversible.
 Friction, viscous, etc. are absent.
 Impossible to achieve in real.
 Cycle with maximum possible Efficiency.
CARNOT CYCLE
Ideal Cycle:
 Processes are Internally Reversible.
 Friction, viscous, etc. are absent.
 Impossible to achieve in real.
OTTO
Cycle
Diesel
Cycle
Brayton
Cycle
Rankine
Cycle
Actual Heat Engines:
 Processes are Irreversible.
 Friction, viscous, etc. are present.
 Possible to achieve in real.
Petrol
Engine
Diesel
Engine
Gas
Turbines
Steam
Turbines
 Reciprocating Engines: petrol and diesel engines are reciprocating engines.
 Terminology of reciprocating engine:
 Bore of Cylinder (D): Inner dimeter of cylinder.
 Top Dead Center (T.D.C): The end position of piston at the top of the
cylinder
 Bottom Dead Center (B.D.C): The end position of piston at the bottom of
cylinder.
Thermodynamic Cycles
Closed Cycles: The
fluid is recycling.
Power Cycles:
Cycles that
produce power or
work as output.
Refrigeration
Cycles: Cycles that
produce cooling as
output.
Gas Cycles: The
phase of fluid
doen't change
between the cycle.
Vapour Cycles:
The phase of fluid
change between
the cycle.
Open Cycles: The
fluid is renewed or
not recycling.

52
 Stroke length (L): the distance between TDC and BDC
 Swept or Stroke volume (VS): the volume between TDC and BDC. 𝑉𝑠 =

4
D2
L
 Clearance Volume (Vc): the space between TDC cylinder head. VC = % VS
 Volume of cylinder (V): V = Vc + VS
 Compression ratio (r): the ratio of cylinder volume to the clearance volume.
𝑟 =
𝑉
𝑉𝑐
 Mean Effective Pressure (mep): the ratio of net workdone to stroke
volume. 𝑚𝑒𝑝 =
𝑛𝑒𝑡 𝑤𝑜𝑟𝑘 𝑑𝑜𝑛𝑒
𝑠𝑡𝑟𝑜𝑘𝑒 𝑣𝑜𝑙𝑢𝑚𝑒
 Internal Combustion engines: combustion takes place inside a cylinder.
1. Spark Ignition Engine (S.I. Engine)
 Petrol is used as the fuel
 Air and fuel (petrol) enter to cylinder and then compressed.
2. Compression Ignition Engines (C.I. Engines)
 Diesel is used as the fuel
 Only air enters to cylinder and then compressed.
 4 stroke petrol engine: the stroke used in a 4 stroke engine are:
1. Suction or intake stroke: Inlet valve is opening, Air and petrol enter, outlet valve is
closed.
2. Compression Stroke: Both valves are closed, Both air and petrol are compressed.
3. Power or Expansion Stroke: Air and Petrol are Combustion, piston move down cause
expansion.
4. Exhaust Stroke: Outlet valve open, Combustion gases go out after expansion, Inlet
valve closed.
 Carnot cycle: it is a reversible thermodynamic cycle established by Sadi Carnot.
PV Diagram of Carnot cycle TS Diagram of Carnot cycle

FUNDAMENTALS OF MECHANICAL ENGINEERING.pdf

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