Automobile Vehicles 2011-12-1

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Chevrolt Volt

AUTOMOTIVE VEHICLES (ME C441)

Dr. D. Jaya Krishna

Mechanical Engg. Department



Course No. : ME C441

Course Title : Automotive Vehicles

Text Books: (1) Joseph Heitner, “ Automotive Mechanics – Principles and Practice” , -

Affiliated East West Press, 2nd edition, 1980.

(2) N. K. Giri, “ Automotive Mechanics” , Khanna Publishers, 8th edition,

2006.

Reference Books:

(3) V. Ganesan, Internal Combustion Engines, Tata McGraw-Hill, 3rd

edition, 2007.

(4) Kripal Singh, Automobile Engineering, - Vol. I & II, Standard Publishers

& Distributors, 1995.

(5) M. L. Mathur and R. P. Sharma, A course in Internal Combustion

Engines, Dhanpath Rai and Sons, 2008.



Sr. No. EvaluationComponent Duration Weightage

(%)

Date, TimeNature of

Component

01 Test I 50 min. 20 25/02 9.00 – 9.50 AM Closed Book

02 Test II 50 min. 20 14/04 9.00 – 9.50 AM Open Book

03 Seminars 10 min. 10 To be announced in the

class

Survey Based

04 Assignment ----- 10 To be announced in the

class

Survey Based

05 Compre. 3 hrs 40 14/05 FN Closed Book

Evaluation Scheme:



LectNo.

Learning Objectives Topics to be covered

01 Fuel-air cycles andactual cycle

Variable specific heats. Dissociation. Valve-timing diagram. Timeloss factor. Heat loss factor. Exhaust blow down.

02 Construction of I.C.engines

Piston. Piston rings. Cylinder. Crank. Connecting rod. Gaskets.Cylinder head.

03 Combustion in S.I.engines

Flame front propagation. Factors influencing the flame speed. Rateof pressure rise. Knocking in SI engines.

04 Combustion in C.I.engines

Delay period. Factors influencing the delay period. Knocking in CIengines. Effect of variables on knocking.

05 Carburetors Carburetion. Engine mixture requirements. Simple carburetor.Calculation of air fuel ratio.

06 Parts of a carburetor Strainers. Float chamber. Choke. Throttle. Metering system. Idlingsystem. Acceleration system. Altitude compensation.

07 Fuel injection system Air injection system. Solid injection system. Injection pumps. Typesof nozzles.

08 Fuel injection system Injection pumps and Fuel injectors.09 Cooling systems Need. Variation of gas temperature. Piston temperature

distribution. Parameters affecting engine heat transfer. Air-cooled

systems.10 Cooling systems Types of water-cooling systems. Radiators. Fans.11 Lubrication systems Causes of engine friction. Function of lubrication. Mechanism of

lubrication. Journal bearing lubrication.12 Lubrication systems Types of lubrication systems. Lubrication of engine components.13 Supercharging Supercharger, Supercharging methods for SI and CI engines14 Turbocharging Turbocharging

15 Supercharging andTurbocharging

Supercharged Engine performance evaluation



16 Clutch Driving system and Plate clutch (uniform pressure anduniform wear).

17 Clutch Cone clutch (uniform pressure and uniform wear).18 Clutch Energy lost by plate clutch during engagement. Centrifugal

clutch.19 Gear box Epicyclic or planetary gear (algebraic method and tabular

method).20 Gear box Torque and tooth load in epicyclic gear trains. Sliding mesh

and constant mesh gears.21 Gear box Epicyclic gears and hydra-matic transmission.22 Propeller shaft Types of driving shafts. Mechanics of Hotchkiss and torque

tube drives.23 Universal joint Slip joint. Hook’s joint.24 Differential and rear

axleDifferential. Rear axle. Axle shaft. Axle housing.

25 Brakes Theory of band brake, block brake, and band and blockbrake. Internal expansion brake.26 Brakes Hydraulic brakes. Hand or parking brakes. Braking of vehicle

moving in a curved path.27 Steering systems Ackerman steering gear. Devis steering gear. Turning circle

radii. Standard steering gears. Power steering.



28 Brake wheel Braking of vehicle. Heat generated due to braking operation.Types of wheels. Wheel alignment.

29 Ignition and starting Theory of automobile batteries. Operation of ignition system.Primary condenser. Distributor. Spark plug. Starting motor.

30 Suspension System Suspension system31 Tyres construction and manufacturing, tyre design consideration32 Emission Control Emission sources, emission control norms

33 to40

Seminars On survey assignments



History of the automobile begins as early as 1769, with

the creation of steam powered automobiles capable of

human transport in 1806







Kawasaki Ninja 250R



chevrolet-beat













Heat Engine: Device that transforms the chemical energy of a fuel into thermal

energy and uses this energy to produce mechanical work

1. External combustion engine: Eg: closed cycle gas turbine, steam engine, steam

turbine.

2. Internal combustion engine : Eg: Petrol engine, Diesel engine, Wankel engine,

open cycle gas turbine

External combustion engine

Internal combustion engine



CLASSIFICATION OF INTERNAL COMBUSTION ENGINES

1. Application2. Basic Engine Design

3. Operating Cycle

4. Working Cycle

5. Valve/Port Design and Location6. Fuel

7. Mixture Preparation

8. Ignition

9. Stratification of Charge

10. Combustion Chamber Design

11. Method of Load Control

12. Cooling

A li i



Application

1. Automotive: (i) Car

(ii) Truck/Bus

(iii) Off-highway

2. Locomotive3. Light Aircraft

4. Marine: (i) Outboard

(ii) Inboard

(iii) Ship

5. Power Generation: (i) Portable (Domestic)(ii) Fixed (Peak Power)

6. Agricultural: (i) Tractors

(ii) Pump sets

7. Earthmoving: (i) Dumpers

(ii) Tippers

(iii) Mining Equipment

8. Home Use: (i) Lawnmowers

(ii) Snow blowers

(iii) Tools

9. Others



2. Basic Engine Design:

1. Reciprocating (a) Single Cylinder

(b) Multi-cylinder (I) In-line

(ii) V

(iii) Radial

(iv) Opposed Cylinder

(v) Opposed Piston

2. Rotary: (a) Single Rotor

(b) Multi-rotor

Wankel



3. Operating Cycle

• Otto (For the Conventional SI Engine)

• Atkinson (For Complete Expansion SI Engine)

• Miller (For Early or Late Inlet Valve Closing type SI Engine)

• Diesel (For the Ideal Diesel Engine)

• Dual (For the Actual Diesel Engine)

Otto cycle



4. Working Cycle (Strokes)

1. Four Stroke Cycle: (a) Naturally Aspirated

(b)Supercharged/Turbocharged

2. Two Stroke Cycle: (a) Crankcase Scavenged

(b) Uniflow Scavenged

(i) Inlet valve/Exhaust Port

(ii) Inlet Port/Exhaust Valve

(iii) Inlet and Exhaust Valve

May be Naturally Aspirated Turbocharged

Four stroke cycle



5. (a) Valve/Port Design

1. Poppet Valve

2. Rotary Valve

3. Reed Valve

4. Piston Controlled Porting

5. (b) Valve Location

1. The T-head

2. The L-head

3. The F-head

4. The I-head: (i) Over head Valve (OHV)

(ii) Over head Cam (OHC)



6. Fuel

1.Conventional: (a) Crude oil derived (i) Petrol

(ii) Diesel

(b) Other sources: (i) Coal(ii) Wood (includes bio-mass)

(iii)Tar Sands

(iv)Shale

2. Alternate: (a) Petroleum derived (i) CNG(ii) LPG

(b) Bio-mass Derived (i) Alcohols (methyl and ethyl)

(ii) Vegetable oils

(iii) Producer gas and biogas

(iv) Hydrogen

3. Blending

4. Dual fueling



7. Mixture Preparation

1. Carburetion

2. Fuel Injection (i) Diesel

(ii) Gasoline

(a) Manifold

(b) Port

(c) Cylinder

Carburetor



8. Ignition

1. Spark Ignition

(a) Conventional

(i) Battery

(ii) Magneto

(b) Other methods

2. Compression Ignition

CI Engine



9. Charge Stratification

1. Homogeneous Charge (Also Pre-mixed charge)

2. Stratified Charge (i) With carburetion

(ii) With fuel injection



10. Combustion Chamber Design

1. Open Chamber: (i) Disc type

(ii) Wedge(iii) Hemispherical

(iv) Bowl-in-piston

(v) Other design

2. Divided Chamber: (For CI): (i) Swirl chamber

(ii) Pre-chamber

(For SI) (i) CVCC

(ii) Other designs



11. Method of Load Control

1. Throttling: (To keep mixture strength constant) Also called ChargeControl

Used in the Carbureted S.I. Engine

2. Fuel Control (To vary the mixture strength according to load)Used in the C.I. Engine

3. Combination

Used in the Fuel-injected S.I. Engine.



12. Cooling

1. Direct Air-cooling

2. Indirect Air-cooling (Liquid Cooling)

3. Low Heat Rejection (Semi-adiabatic) engine.

Liquid Cooling



Basic Engine Components



32

Nomenclature



33

Nomenclature

• Bore = d

• Stroke = L

• Displacement or swept volume =Vs =

• Clearance volume = Vc

• Compression ratio = r

4

dL

2

Vc

VsVc

r

TDC

BDC

V

V





35

Mean Effective Pressure

Mean Effective Pressure (MEP) is a fictitious pressure,

such that if it acted on the piston during the entire

power stroke, it would produce the same amount of net

work.

minmaxV V

W MEP

net

W ki i i l f i



Working principle of engines

• For an engine to work successfully it has to follow a cycle of

operations in a sequential manner• Nicolaus A. Otto has invented the SI engine (1876)

• Rudolf Diesel has invented the CI engine (1892)

• 4-Stroke SI engine http://www.forgefx.com/casestudies/prentic

ehall/ph/engine/engine.htm

• The cycle is completed in 2 revolutions of the crank shaft

k



4-Stroke CI engine

• Due to higher pressures in the cycle of operation the CI

engine has to be more sturdy than SI engine for the same

power output

• It has higher thermal efficiency due to high compression

ratio (approx. 18 : CI and 8 : SI engines)

2-Stroke engines



2-Stroke engines

• To obtain greater output from the same size of the engine ?

• If the two unproductive strokes i.e. suction and exhaust could be

served by alternate arrangement especially without the movement of the piston there will be power stroke in each revolution of crankshaft

• In this arrangement the power output can be doubled (theoretically)

with the same speed of the engine

• Based on this concept Dugald Clark (1878) invented 2-S engine• The main difference between 2-S and 4-S engines is the method of

filling the fresh charge and removing the burnt gases from the cylinder



•The air or charge is induced into thecrankcase through the spring loaded inletvalve when the pressure inside the crankcaseis reduced due to the upward motion of thepiston during compression stroke•During expansion stroke the charge in thecrankcase is compressed•The top portion of the piston has usuallyprojection to deflect the fresh charge towards

the top of the cylinder before flowing throughthe exhaust ports









Actual engines



Actual engines

Valve timing diagram



1. Mechanical factor

2. Dynamic factor (Intake valve timing and exhaust valve timing)

Valve timing diagram for low (left) and high (right) speed engines



Valve timings for 4-S SI Engines



f



Valve timings for 4-S CI Engines

Valve timings for 2-S SI/CI Engines ??

l i i f i



Valve timings for 2-S SI Engines







•Volumetric efficiency indicates the breathing ability of the engine

4-Stoke





• Mean effective pressure is the average pressure inside the cylinders of an IC enginebased on the calculated or measured output



A : piston area



Gas Power Cycles



•In these cycles energy absorbed as heat can be continuously converted intomechanical work• A thermodynamic analysis of the heat engine cycles provides valuable

information regarding the design of new cycles or for improving the existingcycles.

Classification of Cycles:The purpose of a thermodynamic cycle is either to produce power, or to

produce refrigeration/pumping of heat. Therefore, the cycles are broadlyclassified as follows:

• Heat engine (or) power cycles.

• Refrigeration/heat pump cycles.

The nature of the working fluids can be classified into two groups: vapoursand gases. The power cycles are accordingly classified into two groups as:

(1) Vapour power cycles in which the working fluid undergoes a phase change

during the cyclic process.

(2) Gas power cycles in which the working fluid does not undergo any phase

change.

• In the thermodynamic analysis of power cycles, our main interest lies inestimating the energy conversion efficiency or the thermal efficiency



estimating the energy conversion efficiency or the thermal efficiency.

Assumptions:

(i) The working substance consists of a fixed mass of air and behaves as a perfect gas.

The closed system is considered which under goes a cycle process. Therefore, there are no intake or exhaust process.

(ii) The combustion process is replaced by an equivalent heat addition process form an external source. Thus there is no change in the chemical equilibrium of the working fluid and also composition.

(iii) There is no exhaust process; this is replaced by an equivalent heat rejection process (iv) Compression and expansion processes in the cycle are considered as reversible

adiabatic process

(v) The specific heats Cp and Cv of air do not vary with temperature.

Carnot Cycle :



•The isentropic expansion process 2-3 and theisentropic compression process 4-1 can be simulatedquite well by a well-designed turbine and compressor.

•But the isothermal expansion process 1-2 and theisothermal compression process 3-4 are most difficultto achieve.

•Because of these difficulties, a steady-flow Carnot gascycle is not practical.

Since the working fluid is an ideal gas with constantspecific heats, we have, for the isentropic process,

High thermal efficiency of a Carnot cycle is obtained at the

expense of large piston displacement



• The Carnot cycle efficiency can be increased by increasing the pressure ratio. Thismeans that Carnot cycle should be operated at high peak pressure to obtain largeefficiency

Stirling Cycle (Regenerative Cycle) :

The Carnot cycle has a lowmean effective pressurebecause of its very low workoutput. Hence, one of the

modified forms of the cycle toproduce higher meaneffective pressure whilsttheoretically achieving fullCarnot cycle efficiency is theStirling cycle.

•It consists of two isothermal and two constant volume processes. The heat rejectionand addition take place at constant temperature



and addition take place at constant temperature.

Stirling Cycle Processes:

• The air is compressed isothermally from state 1 to 2.

•The air at state-2 is passed into the regenerator from the top at a temperature T1. Theair passing through the regenerator matrix gets heated from TL to TH.

• The air at state-3 expands isothermally in the cylinder until it reaches state-4.

• The air coming out of the engine at temperature TH (condition 4) enters intoregenerator from the bottom and gets cooled while passing through the regeneratormatrix at constant volume and it comes out at a temperature TL, at condition 1 and the

cycle is repeated.

• It can be shown that the heat absorbed by the air from the regenerator matrix duringthe process 2-3 is equal to the heat given by the air to the regenerator matrix during theprocess 4-1, then the exchange of heat with external source will be only during theisothermal processes.

Now we can write, Net work done = W = Qs - QR

Heat supplied = QS = heat supplied during the isothermal process 3-4.

Heat rejected = QR = Heat rejected during the isothermal compression process, 1-2.



The efficiency of Stirling cycle is equal to that of Carnot cycle efficiency when both areworking with the same temperature limits

It is not possible to obtain 100% efficient regenerator and hence there will be always10 to 20 % loss of heat in the regenerator, which decreases the cycle efficiency

Considering regenerator efficiency, the efficiency of the cycle can be written as,

Where, ηR is the regenerator efficiency

Ericsson Cycle:



The Ericsson cycle consists of two isothermal and two constant pressure processes.

The processes are:Process 1-2: Reversible isothermal compression.Process 2-3: Constant pressure heat addition.Process 3-4: Reversible isothermal expansion.Process 4-1: Constant pressure heat rejection.

•The heat addition and rejection take place at constantpressure as well as isothermal processes

•Since the process 2-3 and 3-4 are parallel to each otheron the T-s diagram, the net effect is that the heat need tobe added only at constant temperature T3=T4 and rejected at the constant temperature T1=T2

•The advantage of the Ericsson cycle over the Carnot and

Stirling cycles is its smaller pressure ratio for a given ratioof maximum to minimum specific volume with higher meaneffective pressure.

The Ericsson cycle does not find practical application in piston engines

but is approached by a gas turbine employing a large number of stages with heat exchangers,insulators and reheaters.

Air Standard Otto Cycle:



•The air-standard-Otto cycle is the idealized cycle for the spark-ignition internalcombustion engines.

Process 1-2: Reversible adiabatic compression of air

Process 2-3: Heat addition at constant volume

Process 3-4: Reversible adiabatic expansion of air

Process 4-1: Heat rejection at constant volume

Air Standard Efficiency:

The ratio V2 /V1 is called ascompression ratio, r

•It can be observed that the efficiency of the Otto cycleis mainly the function of compression ratio for the



is mainly the function of compression ratio for thegiven ratio of Cp and Cv.

•If we plot the variations of the thermal efficiency withincrease in compression ratio for different gases, thecurves are obtained as shown in Fig.

• Beyond certain values of compression ratios, theincrease in the thermal efficiency is very small,because the curve tends to be asymptotic

Mean Effective Pressure:

•However, practically the compression ratio of petrol engines is restricted to maximum of9 or 10 due to the phenomenon of knocking at high compression ratios.

• Defined as the ratio of the net workdone to the displacement volume of the piston





Air Standard Diesel Cycle: Process 1-2: Reversible adiabatic Compression.Process 2-3: Constant pressure heat addition.Process 3-5: Reversible adiabatic Compression.

Process 4-1: Constant volume heat rejection.



• It is observed that, the thermal efficiency of the diesel engine can be increased by

increasing the compression ratio, r, by decreasing the cut-off ratio or by using a gas with

large value of γ.

•Since the quantity (rγ-1)/γ(rp-1) in above equation is always greater than unity, the

efficiency of a Diesel cycle is always lower than that of an Otto cycle having the same

compression ratio. However, practical Diesel engines uses higher compression ratios

compared to petrol engines.

Mean effective Pressure:

Limited Pressure Cycle (or Dual Cycle):



Process 1-2: Reversible adiabatic compression.Process 2-3: Constant volume heat addition.Process 3-4: Constant pressure heat addition.Process 4-5: Reversible adiabatic expansion.

Process 5-1: Constant volume heat rejection.

•A value of rp > 1 results in an increased efficiency fora given value of rc and γ. Thus the efficiency of the

dual cycle lies between that of the Otto cycle and theDiesel cycle having the same compression ratio.

Mean Effective Pressure:



Assignment -1



(Dead line : 19th Jan,’12)

1.Actual and ideal cycles (4S/2S/SI/CI)

2. Brayton/Lenoir/Atkinson cycles

3. Valve timing diagram for 4-S SI and CI engines

4. Valve timing diagram for 2-S SI and CI engines

5. Part drawing for SI and CI engines

Comparison of Otto, Diesel and Dual Cycles:



•The important variable factors which are used as the basis for comparison of the cyclesare compression ratio, peak pressure, heat addition, heat rejection and the net work

• In order to compare the performance of the Otto, Diesel and Dual combustion cycles,

some of the variable factors must be fixed

•A comparison of these three cycles is made for the same compression ratio, same heat addition, constant maximum pressure and temperature, same heat rejection and net work output

Same Compression Ratio and Heat Addition:

Otto cycle 1-2-3-4-1

Diesel cycle 1-2-3'-4'-1

Dual cycle 1-2-2”-3”-4”-1

•From the T-s diagram, it can be seen that Area 5-2-3-6 = Area 5-2-3'- 6’ = Area 5 -2-2"-



3"-6" as this area represents the heat input which is the same for all cycles

•Cycles start from the same initial state point 1 and the air is compressed from state 1 to

2 as the compression ratio is same

•It is seen from the T-s diagram for the same heat input, the heat rejection in Otto cycle(area 5-1-4-6) is minimum and heat rejection in Diesel cycle (5-1-4'-6') is maximum

•Otto cycle has the highest work output and efficiency. Diesel cycle has the leastefficiency and Dual cycle having the efficiency between the two

•Otto cycle allows the working medium to expand more whereas Diesel cycle is least.The reason is heat is added before expansion in the case of Otto cycle and the last

portion of heat supplied to the fluid has a relatively short expansion in case of the Dieselcycle

Same Compression Ratio and Heat Rejection:



• Qs > Q’s i.e., heat supplied in the Otto cycle is more than that of the Diesel cycle

•Therefore, the efficiency of the Otto cycle is greater than the efficiency of the Dieselcycle for a given compression ratio and heat rejection

Same Peak Pressure, Peak Temperature and Heat Rejection:



Otto cycle 1-2-3-4

Diesel cycle 1-2'-3-4

•Qs > Q’s. Therefore, the Diesel cycle efficiency is greater than the Otto cycle efficiency

when both engines are built to withstand the same thermal and mechanical stresses

Same Maximum Pressure and Heat Input:



Otto cycle (1-2-3-4-1)

Diesel cycle (1-2'-3'-4'-1)

• The heat rejection for Otto cycle (area 1-5-6-4) is more than the heat rejected in Dieselcycle (1-5-6'-4')

•Hence Diesel cycle is more efficient than Otto cycle for the condition of same maximum

pressure and heat input

• With these conditions, the Diesel cycle has higher compression ratio than that of Ottocycle

•The cycle which is having higher efficiency allows maximum expansion. The Dual cycle

efficiency will be between these two

Same Maximum Pressure and Work Output



• For same work output, the area 1-2-3-4 (work output ofOtto cycle) and area 1-2'-3'-4' (work output of Diesel cycle)are same. To achieve this, the entropy at 3 should be greaterthan entropy at 3'

• The heat rejection for Otto cycle is more than that of diesel

cycle

•The Diesel cycle is more efficient than the Otto cycle. Theefficiency of Dual cycle lies between the two cycles

Fuel air cycles



ue a cyc es

• Difference between air std. cycle and fuel air cycle?

• By fuel air analysis, the effect of fuel air ratio on thermal efficiency can be

studied

• The fuel air cycle analysis takes the following into account

1. Actual composition of the cylinder gases2. Variation of Sp. Heat with temperature

3.Effect of dissociation

4.Variation of no. of molecules

Actual composition of the cylinder gases



Actual composition of the cylinder gases

• Change in air fuel ratio affects the composition of gases before combustion and after

combustion (CO2, CO,H2…)

•Fresh charge comes in contact with the burnt gases (numerical techniques)

Variation of Sp. Heat with temperature

• Most of the gases(except mono atomic) Sp. ht

increase with increase in temperature

• Above 1500 K Cp, Cv values increase much

more rapidly

•As sp. Ht increases more heat required to

produce motion of molecules

•More heat to rise temp.

Dissociation



Dissociation

• Disintegration of combustion products at high

temperature (reverse to combustion)

• mainly CO2 CO +O2 : 1000oC (and partly H2O :

1300 oC)

• More CO reduces further dissociation (rich mixture)

•No dissociation in lean mixture ((less temp)• When temp reduced during expansion+ coolant :

recombination but of no use

•Dissociation max. at correct mixture but for rich mixture

it reduces due to incomplete combustion.• Brake power lost is more with stoichiometric air fuel

mixture due to dissociation



•Less pronounced in CI than SI engines

(heterogeneous mixture & excess air for

complete combustion)

• 3’ dissociation after combustion

• 3’-4” with no re-association

• 3’-4’ with association

No. of molecules

• Fuel-air ratio, type and extent of reaction

Comparison between Air standard cycle and Actual cycle



•Working substance: mixture of air and fuel /products of combustion left out from

previous cycles

•Change in chemical composition of the working substance

•Variation of specific heats with temperature

•Change of composition, temperature and actual fresh charge (due to residual gases)

•Progressive combustion instead of instantaneous combustion

•Heat to/from working fluid

• Exhaust blow down loss•Gas leakage, fluid friction….in actual engines

Fuel aircycles

Diff. : Fuel air cycles

/actual cycles

Time loss factor Instantaneouscombustion



• Loss due to time required for mixing of fuel and air and

also for combustion

•Crank shaft will turn 30o -40o between the spart and end

of combustion (time loss during this period:time loss

factor)

•Peak pressure not at TDC (min volume) (‘bc’ pressure

rise in working stroke)

•Time taken in burning depends

On fuel type,F/A ratio, shape,

size of CC

•Advancing of spark timing

(opt. 15-30o)

Effect of time losses

Spark at TDC, Advace 0OSpark at TDC, Advace 35O

• Opt. spark timing is needed to avoid knocking and



Power loss due to ignition advance

reduce exhaust gas emissions of HC, CO

Heat loss factor

• water jacket, cooling fins, lubricating oil….

• little help full before

the end of expansion ??

Time loss, heat loss and exhaust loss in SI Engine

Exhaust blowdown



• Cylinder press =7 bar(end of exhaust stroke)

•Exhaust valve open 40-70o before BDC

Effect of exhaust valve opening timeon blowdown

Construction of IC Engine





Basic components of an IC engines are



• Cylinder block • Cylinder head • Crankcase • Piston • Piston pin • Piston rings • Connecting rod • Crankshaft • Valves and Valve mechanism • Flywheel • Camshaft • Vibration damper etc.

Cylinder block is the foundation of the engine. It



Cylinder block

contains the following parts

• Precisely finished cylinder in which the piston move

up and down• The inlet and outlet passages • Cooling water flow passages or water jackets in it.

• Precision mirror finish by accurate grinding and honing process• Generally made from grey cast iron and sometimes added with nickel and chromium

• Passages or openings are provided for valve provisions and operations

Cylinder head

Cylinder Head is a separate casting placed on the top of the cylinderblock and held by studs and nuts• Contain the upper end of the combustion chamber and has provisionfor spark plug•A copper and asbestos or sometimes steel and asbestos gasket isplaced between the cylinder head and cylinder block to retaincompression•On the top of the cylinder head rocker arm assembly unit is placed foroperating overhead valves•Cylinder head is made of grey cast iron or aluminium alloy

Crank case is fitted on bottom portion of the cylinder block



Cylinder case

• Contain the upper end of the combustion chamber and has provisionfor spark plug• Also called as oil pan because it holds oil for lubrication purpose

•Gaskets are used to seal the joint between cylinder block andcrankcase•It supports crankshaft and camshaft

Three parts cylinder block, Cylinder head and crankcase form the foundation and main

body of an automobile engine

Crankshaft

Camshaft



Cylinder block

Cylinder head

Cylinder case

Piston helps to convert the heat energy in tomechanical energy



•Space between the piston and cylinder wall is knownas piston clearance (provides space for a thin film oflubrication between piston and cylinder wall)

•Made of aluminium alloys, cast steel, Cast iron orchrome nickel• Grooves are cut around the piston outercircumference to accommodate piston rings to seal thecompressed and expanding gases above the piston•Portions of the pistons that separate the grooves are

called the lands

Piston pin or wrist pin connects piston to the smallend of the connecting rod• It is also cylindrical piece made of case hardened

steel. Piston pin is supported in the piston boss.

Piston rings provides sealing to compressed and expandinggases above the piston• Prevents the oil from entering in to the combustion space• Helps in transmitting the heat of the cylinder wall

Connecting rod provides connection between the piston andcrankshaft• One end small which is connected to the piston by means of



One end small which is connected to the piston by means ofgudgeon pin and other end known as big end connected to thecrankpin of the crankshaft•Connecting rod carries the power /thrust from the piston to the

crankpin of the crankshaft

Crankshaft reciprocating motion of the piston is converted in to rotary motionby means of connecting rod and crankshaft arrangement•Crankshaft is a strong one piece casting of heat treated alloy steel•It consists of crankpins, crank arms or webs, main journals•Main journals of the crankshaft pass through main bearings•Crankshafts have drilled passages through which oil can flow to theconnecting rod from main bearings

•Rear end of the crankshaft carries flywheel andthe front end of the crankshaft carries gears that



the front end of the crankshaft carries gears thatdrives the crankshaft, vibration dampers anddrive belt pulleys

Valves and Valve Mechanism Valve is a device used to close or open a passage toadmit air-fuel mixture or air during suction stroke and expel the burnt gases during

exhaust stroke•Movement of the valve is actuated by an eccentric projection called ‘cam’ of a camshaft•Made of silchrome steel (exhaust valve): Nickle chromium alloysteel (inlet valve)

Poppet valve

ARRANGEMENT OF VALVES

Majority of IC engines also are classified according to theposition and arrangement of the intake and exhaust valves,whether the valves are located in the cylinder head orcylinder block

L-HEAD



•The intake and the exhaust valves are both located on thesame side of the piston and cylinder•The valve operating mechanism is located directly below

the valves, and one camshaft actuates both the intake andthe exhaust valves

I-HEAD The intake and the exhaust valves are both mounted in

a cylinder head directly above the cylinder.This arrangement requires a tappet, a pushrod, and a rockerarm above the cylinder to reverse the direction of valvemovement.Although this configuration is the most popular for currentgasoline and diesel engines, it is rapidly being superseded by

the overhead camshaft.

F-HEADThe intake valves are normally located in the head while the



The intake valves are normally located in the head, while theexhaust valves are located in the engine block.•The intake valves in the head are actuated from the camshaftthrough tappets, pushrods, and rocker arms.

•The exhaust valves are actuated directly by tappets on thecamshaft.

T-HEADThe intake and the exhaust valves are located on oppositesides of the cylinder in the engine block, each requires theirown camshaft.

INGLE OVERHEAD CAMSHAFT The camshaft islocated in the cylinder head.



y•The intake and the exhaust valves are bothoperated from a common camshaft.•The valve train may be arranged to operate directly

through the lifters, as shown in view A, or by rockerarms, as shown in view B.•This configuration is becoming popular forpassenger car gasoline engines.

DOUBLE OVERHEAD CAMSHAFT When the doubleoverhead camshaft is used, the intake and theexhaust valves each operate from separate camshafts

directly through the lifters.•It provides excellent engine performance and is usedin more expensive automotive applications.

Flywheel is a device mounted on the rear end of thecrankshaft, Used to store energy necessary to the carry



crankshaft, Used to store energy necessary to the carrythe engine over the points at which it not receiving powerfrom the explosions• The size of the flywheel varies as per the number of the

cylinder of the engines

Camshaft is a device which gets power from the crankshaft, operates the valves by thecams mounted on it•Camshaft is either placed above the cylinder head or in the cylindrical block depending

upon the valve mechanism• Camshaft has the no of cams along the length•Two cams for each cylinder, one operates inlet valve and other exhaust valve• Camshaft operates fuel pump, distributor and oil pump

Vibration Damper

•During the power strokes power impulses tend to set up twist and untwist actions in the



connecting rod, crankshaft and crankpins

• If not controlled, It could cause the breakage of crankshaft at certain speed

• It is mounted on the front end of the crankshaft

Combustion

•Combustion is a chemical reaction in which certain elements of the fuel like H2 and C

combine with O2 liberating heat energy.

• depending on type of engine the combustion takes place either in a homogeneous or

heterogeneous fuel vapour – air mixture

Homogeneous mixture : SI engines nearly homogeneous mixture (Carburetor)

• Here mixture is formed outside the combustion chamber and initiated at the end of

compression

• Here fuel and oxygen molecules are more or less uniformly distributed

• Flame propagation heat transfer and diffusion of burning fuel molecules from

combustion zone to un burnt zone



• Here fuel and oxygen molecules are more or less uniformly distributed

•Flame front is a narrow zone separating fresh mixture from combustion products

• Normal flame velocity the velocity with which the flame front moves,

w.r.t the unburned mixture in a direction normal to the surface

• Here with a equivalence ratio (Ф) ≈ 1the flame speed is about 40

cm/s. But in SI engine the max flame speed is obtained when Ф (1.1-

1.2)

•By turbulence and incorporating proper air movement, the flame can

be increased

Heterogeneous mixture : Rate of combustion depends on velocity of mutual

diffusion (fuel vapours and air)• Rate of chemical reaction is of minor importance

• Self ignition of fuel air mixture at high temperatures due to high compression ratio is imp.

•Here combustion can take place in an overall lean mixture due to local zones Ф (1-1.2 :

max chemical reaction) Ignition starts in this zone and helps adjoining leaner zones

Combustion in SI EnginesCan be classified into 2 types (Normal and abnormal combustion)



Stages of combustion in SI engine

Theoretical p-theta diagram

Sir Ricardo describes the combustion process inactual SI engine in 3 stages

1st Stage :A->B: Ignition lag/Preparation phase:

• Growth and development of self propagating

nucleus of flame takes place

•Depends on the relationship between

temperature and rate of reaction

2nd Stage :B->C: Propagation of flame:

• 2nd is physical one and is concerned with spread

of the flame

•Flame propagates at constant velocity

•Rate of pressure rise is proportional to the rate of

heat release (as during this stage CC volume

practically remains the same

• During this stage the flame velocity decreases

R f b i b l d l fl l i

3rd Stage :C->D: After burning



• Rate of combustion becomes low due to lower flame velocity

•No pressure rise as piston moving away from TDC

Flame Front Propagation

• For efficient combustion the rate of propagation of

the flame front within the cylinder is quite critical.

•Reaction rate & Transposition rate (Imp. Factors to

determine rate of movement of flame front)

•Reaction rate is the result of chemical combination

process in which flame eats its way into unburned

charge

Details of flame travel

•Transposition rate is due to the physical movement of the flame front and also is the resul

of the pressure difference between the burnt and unburnt gases

•Area I : Slower flame front progress (due to low transposition and low turbulence Small

mass of charge burnt & low reaction rate).

•Area II : More turbulent areaconsumes greater mass of mixture (progresses more

rapidly (BC)) Area III:Less flame speednegligible transposition rate(less unburnt charge

Factors influencing Flame speed

Imp. as flame velocity influences the rate of pressure rise



Effect of mixture strength on the rateof burning

and related to certain types of abnormal combustion

•Turbulence

•Fuel air ratio (min time for combustion)•Intake temperature and pressure (homogeneous mixture)

•Compression ratio (Increases temperature and pressure

ignition advance and 2nd phase of combustion)

•Engine output Pressure due to increase in throttle

•Engine speed turbulence•Engine size large engines (longer flame travel)

Rate of pressure rise

Depends upon mass rate of combustion of mixture

• lower rate of combustion (Curve 3)

•Higher rate of pressure rise rough running & promotes

knocking

Illustration of various combustion rates

Abnormal Combustion

•Loss of power

E i d



• Engine damage

•Recurring preignition

Phenomena of knock in SI Engines

•Very much dependent on the properties of fuel

•If ignition lag is longer than the time required for the

flame front to burn through the unburned charge (no

knocking)• High auto ignition/long ignition lag are desirable

Knock limited parameters

•Knock limited compression ratio

•Knock limited inlet pressure

•Knock limited Indicated mean effective pressure (Performance number: Ratio of Klimep

with the fuel to Klimep with iso-octane when inlet pressure is kept constant.

•Relative performance number(rpn) = Actual performance number/performance number

corresponding to the imep of 100.

Engine Damage From Severe Knock

Damage to the engine is caused by a combination of high temperature and



Damage to the engine is caused by a combination of high temperature andhigh pressure.

Piston Piston crown

Cylinder head gasket Aluminum cylinder head

•Density factors (P,T and ρ are inter related)

Effect of engine variables on Knock



Compression ratio P,T (this is the reason for limiting Comp ratio in SI Engines)

Mass of inducted charge T & ρ

Inlet temperature of mixtureTemperature of combustion chamber walls

Retarding spark timing (spark closer to TDC)

Power output of engine (Decrease in power output decreases temperature)

•Time factors

Turbulence

Engine speed

flame travel distance

Engine size

Combustion chamber shapeLocation of spark plug

•COMPOSITION FACTORS

Fuel air ratio (Min reaction time , max knocking tendency)

Octane vale of fuel (High self ignition temp & low pre flame reactivity knocking)

Paraffin series of HC have max and aromatic series have min tendenc to knock

Combustion in CI Engines•Only air is compressed through high compression ratio (16:1 – 20:1)

•Fuel jet disintegrates into core + spray envelop of air and fuel particles



j g p y p p

•Spray envelop is created by both atomization and vaporization of the fuel

•Fuel air mixture is heterogeneous (orderly and controlled movement must be imparted

to the air and fuel)

•In SI engine ignition occurs at a point whereas in CI engine the ignition occurs at many

points (there is no definite flame front in CI engine)

•In SI engine air fuel ratio remains close to stoichiometric value from no load to full load.

•In CI engine irrespective of load at any speed an approx const supply of air enter

cylinder (Load quantity of fuel injected 18:1 (full load) 80:1 (no load)

•CI engine is always designed to operate with an excess air of 15-40%

0.4 ms after ignition 3.2 ms after ignition

3.2 ms after ignition Late in combustion process

•Ignition delay period (time the 1st fuel droplet hits the air and actual burning phase)

Stages of combustion in CI Engines



Physical delay(beginning of injection&chemical reaction condition)Chemical delay (reactions start slowly and thenaccelerate ignition takes place)

Period of rapid combustion (Uncontrolled combustion)

• Beginning of combustion to the point of maximum pressure



•Longer the delay the more rapid and higher is the pressure rise

Period of controlled combustion

• Fuel droplets injected during second stage burn faster with reduced ignition

delay as soon as they find necessary oxygen

•Further pressure rise is controlled by injection rate

Period of after burning

• The un-burnt and partially burnt fuel particles left in combustion chamber start

burning as soon as they come into contact with oxygen this duration is called

after burning period

•Duration of after burning phase may correspond to 70-80 degrees of crank

travel from TDC

Sequence of events in thye entire combustion process (CI engine)



Factors affecting the delay period (CI Engines)

• Compression ratio delay period



Compression ratio delay period

•Engine speed (with degrees of crankshaft travel delay period increases

• Output ( operating temperature and decreases delay period)•Atomization of fuel and duration of injection (higher fuel injection pressure degree of

atomization and this ignition delay

•Injection timing (optimum ignition advance is 20o bTDC)

Ignition delay with ignition advance (low P,T)

•Quality of fuel (lower self iginition temp. lower

Ignition delay : higher cetane number . lower

Ignition delay

• Intake temperature ignition delay

• Intake pressure reduces auto-ignition temp and

hence ignition delay

Phenomena of Knock in CI Engines



Comparison of Knock in SI and CI Engines

• In SI engines Homogeneous mixtureIntensity of pressure rise more compared to



• In SI engines Homogeneous mixtureIntensity of pressure rise more compared to

CI engines. Therefore often called DETONATION

•No pre-ignition in CI engines compared to SI engines(as in CI, ignition after fuelinjection)

•A good SI engine fuel is a poor CI engine fuel

•SI engines have high octane rating 80-100 (and low cetane rating 20)

•CI engines have high cetane rating 45-65 (and low octane rating 30)

Carburetor

• Carburetor: Device for atomizing and vaporizing



Ca bu eto e ce o ato g a d apo g

the fuel and mixing it with the air in varying

proportions to suit the changing operating conditionsof the vehicle

•Carburetion: Process of breaking up and mixing the

gasoline with air

Factors affecting carburation

• Engine speed



•Vapourization characteristics of the fuel

•Temperature of the incoming air

•Design of the carburetor

Air Fuel mixtures

• Theoretically perfect mixture (Air/fuel): 15:1

•Upper limit for combustion (Air/fuel): 7-10 : 1 (Reddish yellow flame)

•Lower limit for combustion (Air/fuel): 20 : 1 (white flame slowly and irregularly)

Air Fuel mixture Requirements

• Carburetor has to provide mixtures with



general shape (ABCD) [Successful operation]

•Three general ranges of throttle operation

1. Idling (Rich mixture)

2. Cruising (lean mixture)

3. High power (Rich mixture)

Idling :

Simple Carburetor

• Float Chamber



•Fuel discharge nozzle

•Fuel metering orifice

•Venturi

•Throttle valve

•Choke

Mixture Requirements

• Average cruising operation (Air/fuel): 15:1 – 17: 1



•Quick acceleration(rich mixture): 12-13 : 1 (Max. power ratio)



Essential parts of a Carburetor

•Fuel Strainer



• Float Chamber



flipped the carburetor over and took apart thefloat chamber

• Main metering and Idling system

•Controls the fuel feed for crusing and full throttle

ti



operations

•Consists of three principal units

1. Fuel metering orifice through which fuel is drawnfrom float chamber

2. Main discharge nozzle

3. Passage leading to Idling system

Three functions of the main metering systems

1. To proportion the fuel air mixture

2. To decrease the pressure at the discharge nozzle exit

3. To limit the air flow at full throttle

•Hot Idling compensator : Idling mixture becomes too rich under extremely hot

operating conditions causing Idling instability.•HIC (Hot Idling Compensator) system incorporates bi-metallic valve

• Choke and Throttle

•Low cranking speeds and intake temperature need very rich mixture to initiate

b ti ( ti 9 1) [d t l f ti f f l i li id t t ]



combustion (some times 9:1) [due to very large fraction of fuel in liquid state]

•By closing Chokerich mixture due to more pressure drop at venturi throat

•The speed and output is controlled by throttle valve

• Altitude compensation

•With the increase in altitude weight of 1 m3 of air decreases (high alt. rich mixture)•Enrichment (E)



Surprise Test-2



1. Explain 2-Stroke Diesel engine with its valve timing diagram

2. Why Diesel is not used in spark ignition engines

3. Explain the working of simple carburetor with a sketch

Fuel Injection System

•CI engine performance is greatly dependent on effectiveness of Fuel injection system



•In fuel injection fuel speed at delivery point > air speed to atomize the fuel

• In carburetor fuel drawn depends on the air velocity in the venturi but here the fuel

delivered is controlled by a pump which forces fuel under pressure

•Droplets vaporize due to heat transfer from the compressed air

• Functional requirements of an injection system

•Accurate metering of the fuel injected/cycle

imp changing speed and load requirement•Timing the injection of the fuel correctly in the cycle

•Proper control of rate of injection

•Proper atomization of fuel

•Proper spray pattern to ensure rapid mixing of fuel and air

•Uniform distribution of the fuel droplets through out the combustion chamber• To supply equal quantity of fuel to all cylinders

•No lag between beginning and end of injection

• Classification of fuel injection systems

•Air injection system : Fuel is forced into the cylinder by compressed air

•Little used (bulky mlti stage air compressor)



•Little used (bulky mlti stage air compressor)

•Increase in weight reduces Break power

•Higher mean effective pressure ( good mixing of fuel with air)•High viscosity fuels can be used

•Solid injection system : Liquid fuel is directly injected into the combustion chamber

without the aid of air compressor. Therefore called as airless mechanical injection or solid

injection systemThe system comprise mainly of the following components

1. Fuel tank

2. Fuel feed pump ( to supply fuel from fuel tank to the injection system)

3. Injection pump (to meter and pressurise : 200 bar the fuel for injection)

4. Fuel filters (tp prevent dust and abrasive particles)5. Injector (to take the fuel from the pump and distribute it in the combustion chamber by

atomizing into fine droplets)

•Classification of Solid injection system :

1. Individual pump and nozzle system



• Each cylinder is provided with 1 pump and 1 injector

• A separate metering and compression pump is provided

for each cylinder

• Pump is placed close to cylinder or cluster

• High pressure pump plunger is actuated by cam and

produces necessary pressure to open injector valve

• The amount of fuel depends on effective stroke of

plunger

2. Unit injector system

• Pump and injector nozzle are combined in one housing

• Each cylinder provided with one of theses injectors



Each cylinder provided with one of theses injectors

• Once fuel is brought to the injector by low pressure pump

at appropriate time the rocker arm actuates the plunger• The amount of fuel depends on effective stroke of plunger

3. Common rail system

• High pressure pump supplies fuel to a fuel header

• High pressure in header forces the fuel to each nozzle

• Appropriately mechanically operated valve allows the fuel

• The amount of fuel entering is regulated by varying the

length of push rod stroke• Fuel is metered by injectors

3. Distrbutor system• Pump which pressurizes the fuel meters and times it

• The fuel pump after metering supplies required amount of



fuel to a rotating distributor at appropriate time to cylinder

• No. of injection strokes/cycle = no. of cylinders

• A uniform distribution is automatically ensured as there is

one metering element in each pump

Fuel Feed Pump

• Spring loaded plunger is actuated by push rod from

cam shaft

• At minimum lift position of the cam the spring force on the

plunger creates suction

• When cam is turned to its max lift position the plunger is

lifted upwards which results in closing of inlet valve and fuelis forced through out let valve

• Once the operating pressure gets released the plunger

return spring ceases to function resulting in varying of the

pumping stroke (under varying engine loads acc. To quantity

of fuel required by injection pump)

Injection Pump :main objective is to deliver accurate metered quantity of fuel under

high pressure (120 – 200 bar) at correct instant to the injector



1. Jerk type injection Pump

•Consists of reciprocating plunger inside a barrel drivenby camshaft•Near port A fuel is always available under relatively lowpressure•Axial movement through camshaft and rotationalmovement about its axis by rack D

•Port B is the orifice through which fuel is delivered toinjector (closed by means of spring loaded check valve)•When plunger is below A the fuel gets filled above it•When plunger closes A , fuel will flow through C•When rack rotates C closes•Then only opening is B (to the injector) Beginning of

injection and effective stroke of plunger •Injection continues until the helical indention on theplunger uncovers port C closing orifice B•Fuel injection stops and effective stroke ends•Effective stroke of plunger = Time port A covers anduncovers



•In the above fig. the plunger is rotated to the positionshown. But in this the port C is uncovered sooner(shortening the effective stroke)

• Plunger travels the same axial distance for everystroke, the rotation of plunger by the rack determinethe effective stroke (quantity of fuel)

Distributor Type Pump



•Pump has only a single pumping element andfuel is distributed to each cylinder by means of a

rotor•Central longitudinal passage in the rotor and twosets of radial holes

•One set is connected to pump inlet via centralpassage whereas the second set is connected to

delivery lines to injectors of various cylinders•Radial delivery passage in the rotor coincideswith the delivery port for any cylinder the fuel isdelivered to each cylinder in turn

•Small size and light weight

Injection pump governor•In CI engine fuel delivered is independent of injection pump characteristic and air intake

•Fuel delivered by the pump with speed but intake air



• The above results in over fueling at higher speeds and leads to insufficiency of fuel atlow speeds (Idling speeds)

•Drastic reduction of load will cause over speeding to dangerous speeds which needs tobe taken care by injection pump

Usually two types of governors

•Mechanical governor

•Pneumatic governor

•When the engine speed exceeds the limit the weightsfly apart

•Due to this the bell crank lever raises the sleeve andoperate the control lever in downward direction

•The control lever actuates the control rack on the fuelinjection pump (reducing the amount of fuel delivered)

•Mechanical governor

Fuel injectors

•Fuel injectors ensure quick and completecombustion(atomization of fuel into fine droplets)



combustion(atomization of fuel into fine droplets)

•Atomization is done by forcing the fuel through a smallorifice under high pressure

•Needle valve

•Compression spring

•Nozzle

•Injection body

Injection assembly

•Fuel supplied by injection pump exerts force on thespring to lift nozzle valve

•After delivery of fuel (delivery of fuel from pump getsexhausted) the spring pushes the nozzle back to its seat

•Small quantity of fuel is allowed to leak through nozzlevalve and its guide for lubrication (drained back to fueltank by leak off connection)

•Spring tension adjusted by the screw at the top

Nozzle •Nozzle is a part of injector through which liquid fuel is sprayed into the combustionchamber

A l h ld ti f f ll i f ti



A nozzle should satisfy following functions

1. Atomization

2. Distribution of fuel

• Injection pressure (higher pressure better dispersion and penetration of fuel)

• Density of air in the cylinder (higher air density better dispersion)

• Physical properties of fuel (self ignition temperature, vapor pressure, viscosity)

• Prevention of impingement on walls (produces carbon deposits + smoky exhaust+fuel consumption)

• Mixing

Desired properties

•Atomization

•Properly distributed or dispersed in the desired areas•Higher injection pressures better dispersion and greater penetration at desired locations

•Finer droplets (mixing with air)

•Should minimize the quantity of fuel reaching surrounding walls

•Design of nozzle is closely related to the type of combustion chamber(turbulence issues)

•Non-turbulent combustion chamber de ends on nozle desi n and in ection ressure

Nozzle types

• Pintle nozzle : Nozzle vale is extended to form a pinor pintle which protrudes through the mouth of the



nozzle.

• Provides spray operation at low injection pressures

(8-10 MPa)

• Spray cone is generally 60 deg.

• Avoids weak injection and dribbling

• Prevents carbon deposition on the nozzle hole

• Single hole nozzle: At the center of the nozzle body there is asingle hole which is closed by nozzle valve

• Usually hole size : 0.2 mm

• injection pressures (8-10 MPa)

• Spray cone is generally 15 deg.• Nozzle tend to dribble & Spray angle is too narrow to facilitate

good mixing unless higher velocities are used(disadvantage)



Assignment :2 (Dead line : 22nd Feb,2011)

1. Can fuel injection systems be employed in SI engines? Provide valid reason for



1. Can fuel injection systems be employed in SI engines? Provide valid reason foryour answer?

2. Why do Petrol Engine is not used for heavy machines/trains/applications?

3. Compare the Diesel engine and petrol engine cars ? Which one will be morebeneficial and how?

4. Why can't we use diesel engines in motorbikes?

5. Explain and differentiate Direction injection and Indirect injection ?





VI. COMBUSTION IN THE SPARK

IGNITION ENGINE



IGNITION ENGINE

1. THE BASIC COMBUSTION PROCESS2. ANALYSIS OF CYLINDER PRESSURE

DATA

3. IGNITION

4. FLAME PROPAGATION

5. ABNORMAL COMBUSTION

6. INCYLINDER MOTION

VII. SI COMBUSTION CHAMBER

DESIGN



DESIGN

1. DESIGN OBJECTIVES

2. DESIGN OPTIONS FOR CYLINDER

HEAD AND PISTON CROWN

3. SPARK PLUG LOCATION

4. SIZE OF VALVES AND NUMBER OF

VALVES PER CYLINDER

5. AUTOMOTIVE ENGINES

VIII. COMBUSTION IN THE COMPRESSIONIGNITION ENGINE



1. THE BASIC COMBUSTION PROCESS

(a) Delay

(b) Rapid Pressure Rise

(c) Controlled Pressure Rise

(d) After burning

2. ANALYSIS OF CYLINDER PRESSURE DATA

3. FUEL INJECTION

4. INCYLINDER MOTION

IX. CI COMBUSTION CHAMBER

DESIGN



DESIGN

1. DIRECT INJECTION SYSTEMS2. INDIRECT INJECTION SYSTEMS

3. COMPARISON BETWEEN SYSTEMS

4. AUTOMOTIVE ENGINES

5. MARINE ENGINES





















Documents

Automobile Vehicles 2011-12-1