CHENNAI INSTITUTE OF TECHNOLOGY - … · S.No Date Name of the Experiment Page No Signature 1 ......

CHENNAI INSTITUTE OF TECHNOLOGY

DEPARTMENT OF MECHANICAL ENGINEERING

ME 2306 THERMAL ENGINEERING LAB-I

TABLE OF CONTENTS

S.No Date Name of the Experiment Page

No Signature

1

Port Timing Diagram Of Two Stroke Cycle

Petrol Engine

2

Valve Timing Diagram Of Four Cycle Diesel

Engine

3 Redwood Viscometer

4

Cleveland Open Cup Apparatus For Flash And

Fire Point

5

Retardation Test On A Four Stroke Single

Cylinder Diesel Engine By Mechanical

Loading

6 Heat Balance Test On A 4-Stroke Twin

Cylinder Diesel Engine

7

Performance Test On A 4-Stroke Twin Cylinder

Diesel Engine

8

Performance Test On A 4-Stroke Single


9

Performance Test On A Four Stroke Slow

Speed Single Cylinder Diesel Engine By

Mechanical Loading

10

Heat Balance Test On A Four Stroke Slow

Speed Single Cylinder Diesel Engine By

Mechanical Loading

11

Heat Balance Test On A 4-Stroke Single


12

Morse Test On Multi Cylinder Petrol

Engine

13 Study On IC Engines

1. PORT TIMING DIAGRAM OF TWO STROKE CYCLE

PETROL ENGINE

Aim : To draw the port timing diagram of given two stroke cycle petrol engine .

Apparatus Required :

1. Two stroke petrol engine

2. Measuring tape

3. Chalk

Theory and Description :

In the case of two stroke cycle engines the inlet and exhaust valves are not present .

Instead , the slots are cut on the cylinder itself at different elevation and they are called ports.

There are three ports are present in the two stroke cycle engine .

1. Inlet port

2. Transfer port 3. Exhaust port

The diagram which shows the position of crank at which the above ports are open and

close are called as port timing diagram.

The extreme position of the piston at the bottom of the cylinder is called “ Bottom

Dead centre “ [BDC] . The extreme position of the piston at the top of the cylinder is called

“TOP dead centre “ [TDC ]

In two stroke petrol engine the inlet port open when the piston moves from BDC to TDC and is closed when the piston moves from TDC to BDC .

The transfer port is opened when the piston is moved from TDC to BDC and the fuel

enters into the cylinder through this transport from the crank case of the engine . The transfer

port is closed when piston moves from BDC to TDC . The transfer port opening and closing

are measured with respect to the BDC .

The exhaust port is opened , when the piston moves from TDC to BDC and is closed

when piston moves from BDC to TDC . The exhaust port opening and closing are measured

with respect to the BDC.

Tabulation

S.No Piston Position(BDC or

TDC)

Port opening period in

degrees

Inlet port opens

Inlet port closes

Transfer port opens

Transfer port close

Exhaust port opens

Exhaust port closes

Port Timing Diagram

Procedure :

1. Remove the ports cover and identify the three ports . 2. Mark the TDC and BDC position of the fly wheel . To mark this position follow the

same procedure as followed in valve timing diagram .

3. Rotate the flywheel slowly in usual direction (usually clockwise ) and observe the

movement of the piston

4. When the piston moves from BDC to TDC observe when the bottom edge of the

piston . Just uncover the bottom end of the inlet port . This is the inlet port opening

(IPO) condition , make the mark on the flywheel and measure the distance from TDC

5. When piston moves from TDC to BDC observe when the bottom edge of the piston

completely covers the inlet port . This is the inlet port closing (IPC) condition . Make

the mark on the flywheel and measure the distance from TDC .

6. When the piston moves from TDC to BDC , observe , when the top edge of the piston

just uncover the exhaust port . This is the exhaust port opening [EPO] condition .

Make the mark on the flywheel and measure the distance from BDC .

7. When the piston moves from BDC to TDC , observe , when the piston completely

cover the exhaust port ,. This is the exhaust port closing condition [EPC] . Make the

mark on the flywheel and measure the distance from BDC .

8. When the piston moves from TDC to BDC observe, when the top edge of the piston

just uncover the transfer port . This is the transfer port opening [TPO] condition .

Make the mark on the flywheel and measure the distance from BDC

9. When the piston moves from BDC to TDC , observe , when the piston completely

covers the transfer port. This is the transfer port closing [TPC] condition . Make the

mark on the flywheel and measure the distance from BDC .

Result :

The port timing diagram for the given two stroke cycle petrol engine was drawn.

2. VALVE TIMING DIAGRAM OF FOUR

CYCLE DIESEL ENGINE

Aim :

To draw the valve timing diagram of the given four stroke cycle diesel engine.

Apparatus Required :

1. Four stroke cycle diesel engine

2. Measuring tape

3. Chalk

4. Piece of paper

Theory and Description :

The diagram which shows the position of crank of four stroke cycle engine at the

beginning and at the end of suction, compression, expansion, and exhaust of the engine are

called as Valve Timing Diagram.

The extreme position of the bottom of the cylinder is called “Bottom Dead Centre”

[BDC].IN the case of horizontal engine , this is known as “Outer Dead Centre” [ODC]. The

position of the piston at the top of the cylinder is called “Top Dead Centre” [TDC].In case of

horizontal engine this is known as “Inner Dead Centre” [TDC].In case of horizontal

engine this is known as “inner dead centre “ [IDC]

Inlet Valve opening and closing :

In an actual engine , the inlet valve begins to open 5°C to 20 °C before the piston

reaches the TDC during the end of exhaust stroke. This is necessary to ensure that the valve

will be fully open when the piston reaches the TDC. If the inlet valve is allowed to close at

BDC , the cylinder would receive less amount of air than its capacity and the pressure at the

end of suction will be below the atmospheric pressure . To avoid this the inlet valve is kept

open for 25° to 40°after BDC.

Exhaust valve opening and closing

Complete clearing of the burned gases from the cylinder is necessary to take in more

air into the cylinder . To achieve this the exhaust valve is opens at 35° to 45° before BDC and

closes at 10° to 20° after the TCC. It is clear from the diagram , for certain period both inlet

valve and exhaust valve remains in open condition. The crank angles for which the both

valves are open are called as overlapping period . This overlapping is more than the petrol

engine.

Fuel valve opening and closing :

The fuel valve opens at 10° to 15 °before TDC and closes at 15° to 20 ° after TDC .

This is because better evaporation and mixing fuel.

TABULATION

S.No

Piston

position(BDC

or TDC)

Distance from their

respective dead

centers in “cm”

Valve opening period in degrees

Inlet valve opens

Inlet valve

closes

Exhaust valve

opens

Exhaust valve

closes

Valve Timing Diagram

Formula:

( )

D = Circumference of the flywheel

Where,

S = Distance of the valve opening or closing position marked on flywheel with respect to their dead

centre

Procedure :

1. Remove the cylinder head cover and identify the inlet valve , exhaust valve and

piston of particular cylinder.

2. Mark the BDC and TDC position of flywheel

This is done by Rotating the crank in usual direction of rotation and observe the

position of the fly wheel , when the piston is moving downwards at which the

piston begins to move in opposite direction . i.e from down to upward direction .

Make the mark on the flywheel with reference to fixed point on the body of the

engine. That point is the BDC for that cylinder .Measure the circumference . That

point is TDC and is diametrically opposite to the BDC .

3. Insert the paper in the tappet clearance of both inlet and exhaust valves

4. Slowly rotate the crank until the paper in the tappet clearance of inlet valve is

gripped .make the mark on fly wheel against fixed reference . This position

represent the inlet valve open (IVO ). Measure the distance from TDC and

tabulate the distance .

5. Rotate the crank further , till the paper is just free to move . Make the marking on

the flywheel against the fixed reference . This position represent the inlet valve

close (IVC). Measure the distance from BDC and tabulate the distance .

6. Rotate the crank further , till the paper in the tappet clearance of exhaust valve is

gripped . Make the marking on the flywheel against fixed reference . This position

represents the exhaust valve open (EVO) . Measure the distance from BDC and

tabulate .

7. Then convert the measured distances into angle in degrees

Result :

The valve timing diagram for the given four stroke Diesel engine was drawn.

3. REDWOOD VISCOMETER

Aim :

To determine the kinematic viscosity and absolute viscosity of the given lubricating

oil at different temperatures using Redwood Viscometer

Apparatus required :

1)Redwood Viscometer

2)Thermometer 0-100°c

3) Stop watch

4) 50 ml standard narrow necked

5) flask Given Sample of oil

Description :

The redwood viscometer consist of vertical cylindrical oil cup with an orifice in the

centre of its base . The orifice can be closed by a ball . A hook pointing upward serve as a

guide mark for filling the oil . The cylindrical cup is surrounded by the water bath . The water

bath maintain the temperature of the oil to be tested at constant temperature . The oil is heated

by heating the water bath by means of an immersed electric heater in the water bath , The

provision is made for stirring the water , to maintain the uniform temperature in the water

bath and to place the thermometer ti record the temperature of oil and water bath . The

cylinder is 47.625mm in diameter and 88.90mm deep . The orifice is 1.70mm in diameter and

12mm in length , This viscometer is used to determine the kinematic viscosity of the oil.

From the kinematic viscosity the dynamic viscosity is determined .

Theory and Definition :

Viscosity is the property of fluid . It is defined as “The internal resistance offered by

the fluid to the movement of one layer of fluid over an adjacent layer ‘ . It is due to the

Cohesion between the molecules of the fluid . The fluid which obey the Newton law of

Viscosity are called as Newtonian fluid .

The dynamic viscosity of fluid is defined as the shear required to produce unit rate of

angular deformation .

Tabulation

S.no Temperature of

oil

Time taken

forcollecting 50cc

oil in flask

Kinematic viscosity

in stokes

Dynamic viscosity

in stokes

1

2

3

4

5

Formulae used :

Kinematic Viscosity = γ = At – B/t (Stokes)

A = 0.0026

B = 1.72

t = second Density

The kinematic viscosity of the fluid is defined as the ratio of the dynamic viscosity

toss density of the fluid . Its symbol is ‘γ’

γ = μ / ρ μ = Dynamic Viscosity (Stokes) ρ = mass density of oil

Procedure :

(1) Clean the cylindrical oil cup and ensure the orifice tube is free from dirt .

(2) Close the orifice with ball valve.

(3) Place the 50 ml flask below the opening of the Orifice .

(4) Fill the oil in the cylindrical oil cup upto the mark in the cup .

(5) Fill the water in the water bath.

(6) Insert the thermometers in their respective places to measure the oil and water bath

temperatures.

(7) Heat the by heating the water bath, Stirred the water bath and maintain the uniform

temperature .

(8) At particular temperature lift the bal valve and collect the oil in the 50 ml flask and

note the time taken in seconds for the collecting 50 ml of oil . A stop watch is used

measure the time taken . This time is called Redwood seconds .

(9) Increase the temperature and repeat the procedure ‘8’ and note down the Redwood

seconds for different temperatures .

Graph : The following graph has to be drawn

(1)Temperature Vs Redwood seconds

(2)Temperature Vs Kinematic Viscosity

(3)Temperature Vs Dynamic Viscosity

Result :

The kinematic and dynamic viscosity of given oil at different temperatures were

determined and graphs were drawn.

4. CLEVELAND OPEN CUP APPARATUS FOR FLASH AND

FIRE POINT

Aim :

To determine the flash and power point temperatures of the given sample of

lubricating oil using Cleveland open cup apparatus.

Apparatus Required:

1. Cleveland open cup apparatus

2. Thermometer

3. Splinter sticks

4. Sample of oil

Theory and Definition :

The flash point of the lubricating oil is defined as the lowest temperature at which it

forms vapours and produces combustible mixture with air. The higher flash point temperature

is always desirable for any lubricating oil. If the oil has the lower value of flash point

temperatures, it will burn easily and forms the carbon deposits on the moving parts. The

minimum flash temperature of the oil used in IC engines varies from 200°C to 250°C. When

the oil is tested using the open cup apparatus, the temperature is slightly more than the above

temperatures. The flash and fire point temperatures may differs by 20°C to 60°C when it is

tested by open cup apparatus. However, a greater difference may be obtained if some

additives are mixed with oil. The flash and fire power point temperatures depends upon the

volatility of the oil.

Description :

The Cleveland open cup apparatus consists of a cylindrical cup of standard size. It is

held in position in the metallic holder which is placed on a wire gauge. It is heated by means

of an electric heater housed inside the metallic holder. A provision is made on the top of the

cup to hold the thermometer. A standing filling mark is done on the inner side of the cup and

the sample of oil is filled up to the mark. This apparatus will give more accurate results than

the pensky martens closed cup apparatus.

Tabulation:

S. No. Name of the oil sample Temperature ( 0C) Observations

1

2

3

4

5

6

Cleaveland open cup Apparatus

Procedure :

1. Clean the cup and fill it with the given sample of oil up to the filling mark.

2. Insert the thermometer in the holder. Make sure that the thermometer should not

touch the metallic cup.

3. Heat the oil by the means of electric heater so that the sample of oil gives out

vapour at the rate of 10°C per minute.

4. When the oil gives out vapour , introduce the test flame above the oil,

without touching the surface of the oil and watch for flash with flickering sound.

5. Introducing the test flame should not continued at regular intervals until the flash

is observed with peak flickering sound. The temperature corresponding to this

flickering sound is noticed and it is the flash point temperature of the given sample

of oil.

6. Continue the process of heating and introducing the test flame until the oil will

begins to burn continuously and observe the temperature . This is the fire pint

temperature of the given sample of oil.

7. Repeat the test twice or thrice with fresh sample of oil and observe the

results.

8. The observations are tabulated .

Result :

The flash and fire point temperatures of the given sample of oil were

determined using Cleveland open cup apparatus.

1) The flash point temperature of the given sample of oil is °C

2) The fire point temperature is of the given sample of oil is °C

5. RETARDATION TEST ON A FOUR STROKE SINGLE

CYLINDER DIESEL ENGINE BY MECHANICAL LOADING

Aim

To conduct retardation test on a four-stroke single-cylinder diesel slow speed

engine by mechanical loading with specified speed to calculate frictional power. Apparatus Required

1)Tachometer

2) stopwatch

3) Single cylinder diesel engine Specification

Single cylinder, vertical, water cooled, 4-stroke diesel engine.

Make : KIRLOSKAR

Bore : 114.3mm

Stroke : 139.7 mm

Cubic capacity : 1433cc

Speed : 850 rpm

Power : 8HP/7.4 kW

Compression ratio : 16:1

Fuel : High speed diesel oil

Calorific value : 44000 kJ/kg

Specific gravity of oil : 0.8275

Type of loading : Mechanical Loading

Formulae Used

1. Torque(T)

T =

(N-m)

Where,

BP = Brake Power (Kw)

N = Engine Speed (rpm)

2. Frictional Torque (Tf)

Tf = [ T3 / (T2 – T3)] x ( Torque)

3 Frictional Power (FP) (Kw)

3. Mechanical efficiency (ηm)

η (%) Procedure:

1. Calculate maximum load to be applied for a selected engine. 2. Check the fuel supply, water circulation in the water system and lubricating oil in

the oil sump.

3. Ensure no load condition. 4. The engine is started and allowed to run on idle speed for a few minutes.

5. Then the speed is set to the rated speed.

6. Time taken to reach the required speed is noted down at no load condition.

7. Repeat the procedure for drop in speeds 50,100,150,200 and 250.

8. Apply half of the maximum load on the brake drum.

9. Then the speed is set to the rated speed.

10. Time taken to reach the required speed is noted down at half load condition.

11. Repeat the procedure for drop in speeds 50,100,150,200 and 250.

12. After taking the readings unload the engine and allow it to run few minutes and

then stop the engine.

Result:

The retardation test on a four-stroke single-cylinder diesel engine by mechanical

loading with specified speed is conducted and the following parameters were found.

Frictional power =

Mechanical efficiency (ηm) =

6. HEAT BALANCE TEST ON A 4-STROKE TWIN CYLINDER DIESEL

ENGINE

Aim

To conduct Heat balance test on a twin cylinder 4-stroke diesel engine and draw the

characteristics curve.

Specifications:

Twin cylinder, vertical, water cooled, 4-stroke diesel engine.

Make : KIRLOSKAR

Bore : 87.5mm

Stroke : 110mm


Speed : 1500rpm

Power : 10HP/7.4 kW





Type of loading : Electrical swinging field dynamometer with rheostat load

bank

Formulae:

1. Total Fuel consumption TFC =

( Kg/hr)

Where,

q = Fuel consumption (10cc)

t = Time taken for 10cc of fuel consumption (sec)

ρ = Density of diesel =0.83 kg/m3

2. Specific Fuel consumption SFC

SFC = TFC/BP (Kg/Kwhr)

3. Heat input, HI = TFC x calorific value / 3600 ( Kw)

Where CV= 43000 Kj/Kg

4. Brake power, BP =

kW (By using rheostat load bank)

Where,

V = Voltmeter reading (Volts)

I = Ammeter reading (Amperes)

ηg = Generator efficiency = 70%

Brake power, BP =

kW (By using swinging field dynamometer)

Where,

T = Torque = RS N-m

R= Torque arm length = 0.123m

S = spring balance reading (kg)

5. Heat carried by cooling water, Qw = mwCpw(Tw2-Tw1) kW

Where,

Tw1 = Inlet temperature of engine cooling water (0C)

Tw2 = Outlet temperature of engine cooling water (0C)

Cpw = Specific heat of water = 4.187 kJ/kg0K

mw = Mass flow rate of cooling water =

kg/sec

tw = Time taken for flow of 10 litres of water

6. Heat carried by exhaust gas Qg = mgCpg(Tag-Ta) kW

Where, Tag = Exhaust gas temperature (0C)

Ta = Atmospheric temperature (0C)

Cpg = Specific heat of exhaust gas = 1.1 kJ/kg0K

mg = Mass flow rate of exhaust gas = TFC+ma

ma = Mass flow rate of air = CdA ×ρa (kg/sec)

Cd = Co-efficient of discharge of orifice meter = 0.62

A = Area of orifice =

m

2

d = Diameter of orifice = 20mm

Ha = Head of air column = Hw×

m

Hw = Head of water column (m)

ρw = Density of water = 1000kg/m3

ρa = Density of air =

kg/m

3

pa = Atmospheric pressure = 1.01325×105

N/m2

R = Characteristic gas constant of air = 287 J/kg0K

7. Percentage of brake power, %BP =

8. Percentage of heat carried by cooling water, %Qw =

9. Percentage of heat carried by exhaust gas, %Qg =

10. Percentage of unaccounted loss = 100-(%BP + %Qw + %Qg)

Procedure:

1. Calculate maximum load to be applied for a selected engine

2. Check the fuel supply, water circulation in the water system and lubricating oil in the oil

sump.

3. Ensure no load condition

4. The engine is started and allowed to run on idle speed for a few minutes.

5. Gradually the engine is loaded by Electrical load method and the speed is maintained constant.

6. Make sure the cooling water is supplied to the brake drum.

7. Load the engine in steps of 0%, 25%, 50%, 75% & 100% of maximum load to be applied.

8. Note the corresponding readings of spring balance, mass flow rate of water, fuel consumption,

manometer reading, water inlet and outlet temperature, exhaust gas temperature, etc.

9. After taking the readings, unload the engine, allow it to run for few minutes and then stop the

engine.

Result:

The heat balance test on a twin cylinder 4-stroke diesel engine was conducted and the

results were shown in the observation table, graphs are drawn.

7. PERFORMANCE TEST ON A 4-STROKE TWIN CYLINDER DIESEL

ENGINE

Aim

To conduct Performance test on a twin cylinder 4-stroke diesel engine and draw the


Specifications:

Twin cylinder, vertical, water cooled, 4-stroke diesel engine.

Make : KIRLOSKAR

Bore : 87.5mm

Stroke : 110mm


Speed : 1500rpm

Power : 10HP/7.4 kW





Type of loading : Electrical swinging field dynamometer with rheostat load

bank

Formulae:


kW (By using rheostat load bank)

Where,

V = Voltmeter reading (Volts)

I = Ammeter reading (Amperes)

ηg = Generator efficiency = 70%


( Kg/hr)

Where,








5. Indicated power

IP = BP+FP (Kw)

Where,

FP = Friction power (measured from Willan’s Graph)

6. Brake thermal efficiency (ηbth) =

(%)

7. Indicated thermal efficiency (ηIth) =

(%)

8. Mechanical efficiency (ηm) =

(%)

9. Indicated mean effective pressure

IMEP = (BP x 60) / (ALNK) (kN/m2)

10. Brake mean effective pressure (BMEP)

BMEP = (BP x 60) / ALNK (kN/m2)

Where,

L = Length of stroke (m)

A = Area of piston =

(m

2)

d = Bore diameter (m)

N = Number of working strokes in one complete cycle

For 4-stroke n = N/2

For 2-stroke n = N

K = Number of cylinders

11. Volumetric efficiency ηv =

(%)

Actual volume of air sucked into cylinder (va) = Cd×A×√2gh m2/hr

Where, H =

A = Area of orifice

(m

2)

h = Manometer reading (m)

density of water (kg/m3)

= density of air

Cd = Coefficient of discharge

of air =

12. Swept volume (vs) =

Where,

D = dia of bore

L = Length of stroke

N = Speed of engine in RPM

Procedure


2. Check the fuel supply, water circulation in the water system and lubricating oil in the

oil sump.



5. Gradually the engine is loaded by electrical dynamometer and the speed is maintained

constant.

6. Load the engine in steps of 0%, 25%, 50% , 75% & 100% of maximum load to be

applied.

7. Note the corresponding readings of voltmeter, ammeter and fuel consumption.

8. After taking the readings, unload the engine, allow it to run for few minutes and then

stop the engine

Result:

The performance test was conducted on the Twin cylinder diesel engine and the

performance curves were drawn.

8. PERFORMANCE TEST ON A 4-STROKE SINGLE CYLINDER

DIESEL ENGINE

Aim

To conduct Performance test on a Single cylinder 4-stroke diesel engine and draw the


Specifications:


Make : KIRLOSKAR

Bore : 87.5mm

Stroke : 110mm


Speed : 1500rpm

Power : 5HP/3.7 kW






Formulae:


kW

Where,

N= Speed of the engine

T= torque developed across the brake drum

BP= brake power in Kw


( Kg/hr)

Where,








4. Indicated power

IP = BP+FP (Kw)

Where,



(%)


(%)


(%)





Where,



(m

2)




For 2-stroke n = N



(%)


Where, H =

A = Area of orifice

(m

2)



= density of air


of air =


Where,

D = dia of bore



Procedure



oil sump.



5. Gradually the engine is loaded by mechanical brake method and the speed is

maintained constant.


7. Load the engine in steps of 0%, 25%, 50%, 75% & 100% of maximum load to be

applied.

8. Note the corresponding readings of spring balance, fuel consumption, manometer

reading .


stop the engine.

Result:

The performance test was conducted on the Single cylinder diesel engine and the


9. PERFORMANCE TEST ON A FOUR STROKE SLOW SPEED

SINGLE CYLINDER DIESEL ENGINE BY MECHANICAL

LOADING Aim

To conduct Performance test on a four-stroke single-cylinder SLOW speed diesel

slow speed engine by mechanical loading method. Apparatus Required

1)Tachometer

2) stopwatch

3) Single cylinder diesel engine Specification Single cylinder, vertical, water cooled, 4-stroke diesel engine.

Make : KIRLOSKAR

Bore : 114.3mm

Stroke : 139.7 mm


Speed : 850 rpm

Power : 8HP/7.4 kW






Formulae Used:


kW

Where,

N= Speed of the engine

T= torque developed across the brake drum

BP= brake power in Kw


( Kg/hr)

Where,








5. Indicated power

IP = BP+FP (Kw)

Where,



(%)


(%)


(%)





Where,



(m

2)




For 2-stroke n = N



(%)


Where, H =

A = Area of orifice

(m

2)



= density of air


of air =


Where,

D = dia of bore



Procedure



oil sump.



5. Gradually the engine is loaded by mechanical brake method and the speed is

maintained constant.


7. Load the engine in steps of 0%, 25%, 50%, 75% & 100% of maximum load to be

applied.

8. Note the corresponding readings of spring balance, fuel consumption, manometer

reading .


stop the engine.

Result:

The performance test was conducted on the single cylinder slow speed diesel engine and the


10. HEAT BALANCE TEST ON A FOUR STROKE SLOW SPEED

SINGLE CYLINDER DIESEL ENGINE BY MECHANICAL

LOADING Aim

To conduct Performance test on a four-stroke single-cylinder SLOW speed diesel

slow speed engine by mechanical loading method. Apparatus Required

1)Tachometer

2) stopwatch

3) Single cylinder diesel engine Specification Single cylinder, vertical, water cooled, 4-stroke diesel engine.

Make : KIRLOSKAR

Bore : 114.3mm

Stroke : 139.7 mm


Speed : 850 rpm

Power : 8HP/7.4 kW






Formulae Used:


( Kg/hr)

Where,









Where,

T = Torque = RS N-m

R= Torque arm length = 0.15 m



Where,



Cpw = Specific heat of water = 4.187 kJ/kg0K


kg/sec










m

2



m




kg/m

3


N/m2






Procedure:



sump.



5. Gradually the engine is loaded by Mechanical load method and the speed is maintained

constant.






engine.

Result:

The heat balance test on a single cylinder 4-stroke slow speed diesel engine was

conducted and the results were shown in the observation table, graphs are drawn.

11. HEAT BALANCE TEST ON A 4-STROKE SINGLE CYLINDER

DIESEL ENGINE

Aim

To conduct Performance test on a Single cylinder 4-stroke diesel engine and draw the


Specifications:


Make : KIRLOSKAR

Bore : 87.5mm

Stroke : 110mm


Speed : 1500rpm

Power : 5HP/3.7 kW






Formulae:


( Kg/hr)

Where,









Where,

T = Torque = RS N-m




Where,



Cpw = Specific heat of water = 4.187 kJ/kg

0K


kg/sec










m

2



m




kg/m

3


N/m2






Procedure:



sump.



5. Gradually the engine is loaded by Mechanical load method and the speed is maintained

constant.






engine.

Result:

The heat balance test on a single cylinder 4-stroke diesel engine was conducted and the

results were shown in the observation table, graphs are drawn.

12. MORSE TEST ON MULTI CYLINDER PETROL ENGINE

Aim :

To conduct morse test on given multi cylinder petrol engine in order to determine

the indicated power developed in the each cylinder of the engine and to determine the

mechanical efficiency. Apparatus Required :

1. Multi cylinder petrol engine with ignition cut off

arrangement

2. Loading arrangements

3. Tachometer Theory and Description :

For slow speed engine the indicated power is directly calculated from the

indicator diagram. But in modern high speed engines , it is difficult to obtain

accurate indicator diagram due to inertia forces , and therefore , this method cannot be

applied . In such cases the morse test can be used to measure the indicated power and

mechanical efficiency of multi cylinder engines . The engines test is carried out as follows

. The engine is run at maximum load at certain speed . The B.P is then measured when all

cylinders are working .

Then one cylinder is made in operative by cutting off the ignition to that cylinder . As a result of this the speed of the engine will decrease . Therefore , the load on the engine is reduced

so that the engine speed is restored to its initial value . The assumption made on the test

is that frictional power is depends on the speed and not upon the load on the engine . Formulae used:


Where,

T = Torque = RS N-m



2. Total Fuel consumption TFC = ( Kg/hr)

Where,








5. Indicated power

Ip = ip1 + ip2 + ip3 + ip4 kw

Where,

Ip1 = bp – bp1

Ip2 = bp – bp2

Ip3 = bp – bp3

Ip4 = bp – bp4

6. Brake thermal efficiency (ηbth) = (%)

7. Indicated thermal efficiency (ηIth) = (%)

8. Mechanical efficiency (ηm) = (%)

9. Frictional Power

Fr P = BP – IP (Kw)

Procedure : 1. Check the engine for fuel availability, lubricant and cooling water connections .

2. Release the load completely on the engine and start the engine in no load conditions

and allow the engine to run for few minutes to attain the rated speed.

3. Apply the load and increase the load upto maximum load. (All four cylinders

should be in working ) . Now note the load on the engine and speed of the engine say

the speed is ‘N’ rpm 4.Cut-off the ignition of first cylinder, Now the speed of engine decreased . Reduce the load on the engine and bring the speed of the engine to ‘N’ rpm. Now note the load on the engine.

5.Bring the all four cylinders are in working conditions and cut off the 2nd

, 3rd

and 4th

cylinder in turn and adjust the load to maintain same ‘N’ rpm and note the load . Result:

Morse test was conducted on given petrol engine and indicated power developed in each cylinder are determined and mechanical efficiency are also determined .

STUDY ON IC ENGINES

Aim:

To study on a 4 stroke petrol engine and its components.

Operation

1. Induction

2. Compression

3. Power

4. Exhaust

As their name implies, four-stroke internal combustion engines have four basic steps that repeat

with every two revolutions of the engine:

(1) Intake/suction stroke (2) Compression stroke (3) Power/expansion stroke and (4) Exhaust

stroke

1. Intake stroke: The first stroke of the internal combustion engine is also known as the suction

stroke because the piston moves to the maximum volume position (downward direction in the

cylinder) creating a drop in pressure. The inlet valve opens as a result of the cam lobe pressing

down on the valve stem, and the vaporized fuel mixture is sucked into the combustion chamber.

The inlet valve closes at the end of this stroke.

2. Compression stroke: In this stroke, both valves are closed and the piston starts its movement

to the minimum volume position (upward direction in the cylinder) and compresses the fuel

mixture. During the compression process, pressure, temperature and the density of the fuel

mixture increases.

3. A Power stroke: When the piston reaches a point just before top dead center, the spark plug

ignites the fuel mixture. The point at which the fuel ignites varies by engine; typically it is about

10 degrees before top dead center. This expansion of gases caused by ignition of the fuel

produces the power that is transmitted to the crank shaft mechanism.

4. Exhaust stroke: In the end of the power stroke, the exhaust valve opens. During this stroke, the

piston starts its movement in the maximum volume position. The open exhaust valve allows the

exhaust gases to escape the cylinder. At the end of this stroke, the exhaust valve closes, the inlet

valve opens, and the sequence repeats in the next cycle. Four-stroke engines require two

revolutions.

Different Parts of I.C. Engine

Cylinder, Cylinder head, Piston, Piston rings, Gudgeon pin, Connecting rod,

Crankshaft, Crank, Engine bearing, Crank case, Flywheel etc.

Cylinder Head

Also referred to as the top end, the cylinder head houses the pistons,

valves, rocker arms and camshafts.

Valves

A pair of valves, used for controlling fuel intake and exhaust, is

controlled by a set of fingers on the camshaft called lobes. As the intake

valve opens, a mixture of fuel and air from the carburetor is pulled into

the cylinder. The exhaust valve expels the spent air/fuel mixture after

combustion.

Camshaft

Usually chain or gear-driven, the camshaft spins, using its lobes to

actuate the rocker arms. These open the intake and exhaust valves at

preset intervals.

The Piston

The piston travels up and down within the cylinder and compresses

the air/fuel mixture to be ignited by a spark plug. The combustive

force propels the piston downward. The piston is attached to a

connecting rod by a wrist pin.

Piston rings:

These are circular rings which seal the gaps made between the

piston and the cylinder, their object being to prevent gas escaping and

to control the amount of lubricant which is allowed to reach the top of

the cylinder.

Gudgeon-pin:

This pin transfers the thrust from the piston to the connecting-rod

small-end while permitting the rod to rock to and fro as the crankshaft

rotates.

Connecting-rod:

This acts as both a strut and a tie link-rod. It transmits the linear

pressure impulses acting on the piston to the crankshaft big-end

journal, where they are converted into turning-effort.

Crankshaft

The crankshaft is made up of a left and right flywheel connected to

the piston's connecting rod by a crank pin, which rotates to create the

piston's up-and-down motion. The cam chain sprocket is mounted on the

crankshaft, which controls the chain that drives the camshaft.

Carburettor

The carburetor is the control for the engine. It feeds the engine with

a mixture of air and petrol in a controlled volume that determines the

speed, acceleration and deceleration of the engine. The carburetor is

controlled by a slide connected to the throttle cable from the handlebar

twist grip which adjusts the volume of air drawn into the engine.

IC ENGINE

Tabulation

S.No Load

in %

Load

Applied

in

Amps

Voltmeter

Reading in

Volts

Time taken

for 10 cc Fuel

Consumption

(Sec)

Manometer

Reading(m) *

10 -2

Cooling water

Temperature

( o

C) Exhaust Gas

temperature(Tg)

(oC)

Time taken

for collecting

1 Litre of

water(Sec) h1 h2 H Tw1 Tw2

Tabulation

S.No TFC

(Kg/hr)

Heat

Input

(Kw)

Brake

Power

(Kw)

Heat

carried

by

Cooling

Water

(Qw) in

Kw

Mass of

the Gas

Mg *

10 -3

In Kg

Heat

carried

by

Exhaust

Gas

(Qg) in

Kw

Unaccounted

Loss of Heat

(Qun) in Kw

% of

BP

(%)

% of

Heat

carried

by

water

(%)

% of

Heat

carried

by

Exhaust

(%)

Un

accounted

Heat loss

in %

Tabulation

S. No.

Drop in

Speed (rpm)

Time for fall of

speed at

no load condition

(T2) sec

Time for fall of

speed at half

load condition

(T3) sec

Frictional Torque (Tf)

N-m

Frictional power(FP) from

graph (KW)

Fp avg

Tabulation:

S.No Load in %

Weight (Kg) Time taken for 10

cc Fuel

Consumption

(Sec)

Manometer Reading(m) * 10 -2

W1 W2 W h1 h2 h

1

2

3

4

5

Tabulation:

Sl.

No.

Torque

TFC

SFC

HI

BP

IP

ηm

ηbt

ηit

BMEP

IMEP

N-m

kg/hr

kg/hr

kW

kW

kW

kW

%

%

%

bar

bar

1

2

3

4

5

Tabulation

S.No Load

in %

Mechanical

Load(Kg) Time taken

for 10 cc Fuel

Consumption

(Sec)

Manometer

Reading(m) * 10 -2

Cooling water

Temperature

( o

C) Exhaust Gas

temperature(

Tg) (oC)

Time taken for

collecting 1

Litre of

water(Sec) W1 W2 W h1 h2 h Tw1 Tw2

Tabulation

Tabulation

S.No TFC

(Kg/hr)

Heat

Input

(Kw)

Brake

Power

(Kw)

Heat

carried

by

Cooling

Water

(Qw) in

Kw

Mass of

the Gas

Mg *

10 -3

In Kg

Heat

carried

by

Exhaust

Gas

(Qg) in

Kw

Unaccounted

Loss of Heat

(Qun) in Kw

% of

BP (%)

% of

Heat

carried

by

water

(%)

% of

Heat

carried

by

Exhaust

(%)

Un

accounted

Heat loss

in %

1

2

3

4

5

Tabulation

S No

Conditions

Loading

Speed

Rpm

BP ‘KW’ W1 kg

W2 kg

W1 – W2 kg

Net load W in ‘N’

1

All cylinders are working

2

First cylinder was cut off

and remaining are in working

3

Second cylinder was cut off


4

Third cylinder was cut off


5

Fourth cylinder was cut off


Note : The speed should be same for all readings

Tabulation

S.No Load in %

Load Applied

in Amps

Voltmeter Reading

in Volts

Time taken for 10 cc

Fuel Consumption

(Sec)

Manometer Reading(m) * 10 -2

h1 h2 H

CHENNAI INSTITUTE OF TECHNOLOGY - … · S.No Date Name of the Experiment Page No Signature 1 ......

Documents

Transcript of CHENNAI INSTITUTE OF TECHNOLOGY - … · S.No Date Name of the Experiment Page No Signature 1 ......