EFFECT OF COMBUSTION CHAMBER GEOMETRY ON THE PERFORMANCE OF A CI ENGINE

NAME USN

NISHANT SARASWAT 1DS11ME060

ROHAN BANERJEE 1DS11ME084

SUMANT RANJAN 1DS11ME110

SUPRIYO SARKAR 1DS11ME111

DEPARTMENT OF MECHANICAL ENGINEERINGDAYANANDA SAGAR COLLEGE OF ENGINEERING

BATCH B9

UNDER THE GUIDANCE OF M.R. KAMESH

ASSOCIATE PROFESSOR

OBJECTIVE• DEVELOPMENT OF PISTONS - DIFFERENT

COMBUSTION CHAMBER GEOMETRY

• TESTING THE ENGINE WITH THE DIFFERENT PISTONS

• COMPARING THE RESULTS OBTAINED WITH THE CONVENTIONAL PISTON

LITERATURE SURVEY• A comparative study of open (HCC, SCC and TCC) and re-entrant combustion

chamber geometries (SRCC and TRCC) on the performance and emission characteristics of a diesel engine is investigated[1]

• It reduces the emissions of NOx and HCs this leads to more efficient combustion thus controlling pollution. [2]

• Initially the isothermal performance of swirl combustors is considered, and it is demonstrated that, the flow is often not axisymmetric but three-dimensional time-dependent. Sufficient information is also available to indicate that staged fuel or air entry may be used to minimize noise, hydrocarbon, and NOx emissions from swirl combustors.[3]

METHODOLOGY

EVENT

1.DETAILED LITERATURE SURVEY

2.MARKET SURVEY OF READILY AVAILABLE PISTONS

3.DESIGNING OF THE PISTONS

4.FABRICATION

5.TESTING

6.RESULTS AND DISCUSSIONS

SPECIFICATIONS OF THE KIRLOSKAR AV1 ENGINE

ITEM SPECIFICATIONS

ENGINE POWER 3.7 KW

CYLINDER BORE 80mm

STROKE LENGTH 110mm

ENGINE SPEED 1500 RPM

COMPRESSION RATIO 16.5:1

SWEPT VOLUME 553 cc

STROKES 4

INJECTION PRESSURE 175 bar

TIMELINEOBJECTIVES DATE OF INITIATION DATE OF COMPLETION

LITERATURE SURVEY MID JANUARY 10-02-2015

MARKET SURVEY 10-02-2015 20-02-2015

DESIGN 20-02-2015 06-03-2015

FABRICATION 07-03-2015 26-03-2015

TESTING 27-03-2015 06-04-2015

MODIFICATION(IF REQUIRED)

6-04-2015 09-04-2015

RESULTS AND DISCUSSION 10-04-2015 13-04-2015

MARKET SURVEY(COSTS INVOLVED)

SERIAL NUMBER

PARTICULARS UNITS COST(INR)

1 PISTON SET 4 5200

2 FILLING 4 4000

3 FABRICATION 4 4000

4 TESTING - 2000

5 TOTAL COST - 15200

SWIRL AND SQUISH[4]• Swirl : Swirl is usually defined as organized rotation of the charge about

the cylinder axis.Swirl is created by bringing the intake flow into the cylinder with an initial angular momentum.

• Squish : Squish is the name given to the radially inward or transverse gas motion that occurs towards the end of the compression stroke when a portion of the piston face and cylinder head approach each other closely.

NEED FOR SWIRL AND SQUISH• UNIFORM INTAKE DUE TO INITIAL ANGULAR

MOMENTUM

• RAPID MIXING OF THE AIR MIXTURE AND INJECTED FUEL

• SPEEDS UP THE COMBUSTION PROCESS

• IMPROVES SCAVENGING

MODIFICATIONSWe modify the combustion chamber of the basic AV1 piston into the following types.

For all the combustion chamber configurations bowl volume is kept constant.

EXPERIMENTAL PROOF OF CONSTANT BOWL VOLUME

• The bowl volume is kept constant to approximately 21cc.• As a visual proof to this, the hemispherical piston is filled with blue ink.• The same amount of ink is transferred to all the other pistons with varying

combustion chamber geometries using a syringe.• It is found out that the volume of all pistons is constant.

BASIC COMBUSTION CHAMBER GEOMETRY

The basic shape of the combustion chamber is hemispherical in a Kirloskar AV1 piston

Combustion chamber

Compression rings

Oil ring

EXPERIMENTAL SETUP

EXPERIMENTAL CONDITIONS• INJECTION PRESSURE : 175 bar

• EGR : OFF

• AIR PREHEATER : OFF

• ENGINE COOLING WATER : 2lpm

• CALORIMETER COOLING WATER : 2.5lpm

DESIGN OF SHALLOW COMBUSTION CHAMBER

INITIAL GEOMETRY (HCC) FINAL GEOMETRY (SCC)

(SECTIONAL FRONT VIEW)

THE PISTON(SCC) BEFORE TESTING

THE PISTON (SCC) AFTER TESTING

Image : Injection spots after combustion.

DESIGN OF TOROIDAL COMBUSTION CHAMBER

INITIAL GEOMETRY (HCC) FINAL GEOMETRY (TCC)

(SECTIONAL FRONT VIEW)

THE PISTON (TCC) BEFORE TESTING

THE PISTON (TCC) AFTER TESTING

Image : Injection spots after combustion.

AIR FLOW IN RE-ENTRANT TYPE COMBUSTION CHAMBERS

• A re-entrant bowl is used to promote more rapid air fuel mixing in the bowl.

• Conventional bowl : Swirling air enters the bowl and flows down to the base of the bowl then inward and upward in toroidal motion

• Re-entrant bowl : Swirling air enters the bowl and spreads downwards and outwards into the undercut region and divides into a stream rising up the bowl sides and a stream flowing along the bowl base.

DESIGN OF TOROIDAL RE-ENTRANT TYPE COMBUSTION CHAMBER

INITIAL GEOMETRY (HCC) FINAL GEOMETRY(TRCC)

(SECTIONAL FRONT VIEW)

THE PISTON (TRCC) BEFORE TESTING

THE PISTON (TRCC) AFTER TESTING

DESIGN OF SHALLOW RE-ENTRANT TYPE COMBUSTION CHAMBER

(IEW)

INITIAL GEOMETRY (HCC)FINAL GEOMETRY(SRCC)

(SECTIONAL FRONT VIEW)

THE PISTON (SRCC) BEFORE TESTING

THE PISTON (SRCC) AFTER TESTING

FRICTIONAL POWER TCC PISTON

FRICTIONAL POWER TRCC PISTON

FRICTIONAL POWER SCC PISTON

FRICTIONAL POWER SRCC

COMPARISON OF FRICTIONAL POWER

TYPE OF PISTON FRICTIONAL POWER (KW)

TCC 3.5

TRCC 3.6

SCC 4.6

SRCC 3.2

COMPARISON OF LOAD vs MECHANICAL EFFICIENCY (%)

COMPARISON OF BRAKE THERMAL EFFICIENCY(%) WITH LOAD

COMPARISON OF SFC WITH LOAD

FUTURE SCOPETHE EXPERIMENT CAN BE FURTHER ON BE EXTENDED TO THE FOLLOWING CONDITIONS.

• VARYING INJECTION PRESSURE.• WITH THE PRESENCE OF EGR.• WITH PREHEATED INTAKE AIR.• VARYING COMPRESSION RATIOS.

CONCLUSION

• CONSIDERABLE IMPROVEMENT IS SEEN IN THE MECHANICAL EFFICIENCIES OF THREE PISTONS OVER THE STOCK PISTON

• SFC IS OBSERVED TO BE HIGH AT LOWER LOADS BUT AT HIGHER LOADS, IT IS ALMOST THE SAME AS THE STOCK PISTON(HAVING MORE MECHANICAL EFFICIENCY )

BIBLIOGRAPHY

[1]S.Jaichandar, K.Annamalai and P.Arikaran."Comparative evaluation of pongamia biodiesel with open and re-entrant combustion chambers in a DI diesel engine", International journal of automotive engineering and technology, Volume 3 issue 2 pp66-73 2014.

[2] Rehman H. , Phadatare A.G., "Diesel engine emissions and performance fropm blends of

Karanja Methyl Ester and Diesel", Biomass and Bioenergy 29:393-397, 2004 [3]B.V.V.S.U.Prasad,C.S.Sharma,T.N.C.Anand, R.V.Ravikrishna."High swirl inducing piston

bowls in small diesel engine for emission reduction." Applied energy, Elsvier 88 2355-2367 2011.

[4]John B. Heywood . "International combustion engine fundamentals." New York; Mc Graw

Hill Book Company 1988.

[5] Jayashankara B, Ganesan V, "Effect of fuel injection timing and initial intake pressure on a performance of DI diesel engine". Energy converse manage 2010; 51(10); 1835-48.

[6]Zhengbai L, Xinqun G. "Investigation of effect of piston bowl and fuel injector offsets on combustion and offset DI diesel engines." SAE paper 2002-01-1748.

[7]Philip WS, Ruthland CJ, "modeling the effect of flow characteristics on diesel engine

combustion." SAE paper 950282.