Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Application...
Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Application...
Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Application...
Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Application...
Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Application...
Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Application...
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International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.

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  1. 1. Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Applications (IJERA) ISSN: 2248-9622www.ijera.com Vol. 3, Issue 3, May-Jun 2013, pp.1402-14071402 | P a g eThermal Analysis of Piston for the Influence on Secondary motionVinay V. Kuppast1, Dr.S.N.Kurbet2, H.D.Umeshkumar3, Adarsh B.C41,2(NVH Research Lab, Department of Mechanical Engineering, Basaveshwar Engineering College, Bagalkot-587102. Karnataka, INDIA.)3.4(Department of Mechanical Engineering, AIT, Chikmagalur, Karnataka, INDIA.)ABSTRACTThe gas force due to the combustion inthe cylinder of an IC engine will cause the pistonto move with primary motion and secondarymotion. The primary motion of the piston fromTDC to BDC is linear in nature. This motion isdesired for translation of motion of enginecomponents. Secondary motion is due to thetransverse motion of the piston while pistonmoving from TDC to BDC and vice-versa. Thesecondary motion of the piston is considered asthe main source for the piston slap, which in turncauses the impact on the cylinder walls resultingin engine vibration and noise. In the presentstudy, an effort is made to understand the effectof the thermal load, generated by the combustionof fuel inside the cylinder, on the pistondeformation and thermal stresses induced inpiston. This deformation of the piston inside thecylinder causes the gap between the cylinder andpiston to vary and also the piston to movetransversely along with impact forces. Thetransverse motion of the piston in the cylinder isobserved experimentally by measuring the gapbetween piston and cylinder at thrust side loadcondition. Finite element analysis (FEA) isconsidered as one of the best numerical tools tomodel and analyze the physical systems. FEA iscarried out to find the piston deformation due tothermal load on the piston for the temperaturedata obtained from experiments. The threedimensional piston is modeled in CATIA V5 R19and analyzed in ANSYS 12 solver. The simulationresults are used to predict effect of temperatureon piston deformation and its secondary motionwhich are the principal source of engine vibrationand noise.Keywords – Deformation, FEA, Piston, Secondarymotion, SimulationI. INTRODUCTIONAs gas forces the piston in IC engine, thepiston will move with primary motion and secondarymotion. Secondary motion is a transverse motion ofthe piston while piston moving from TDC to BDCvisa-versa. Transverse motion produced is notdesired in IC engines because it produces piston slapand twisting movement in the remaining part likepin, connecting rod and crank shaft. When the hotcombusted gases impact the piston heat will transferto the piston and the engine parts. As soon the hotgases impact the piston, the thermal stresses willdevelop in the piston which results in pistondeformation [1]. Figure 1 shows the schematicdiagram of engine parts with lateral motion of theparts [2]..Fig. 1 Schematic of engine partsPiston Temperature DistributionThe piston crown is exposed to very highcombustion temperatures. Figure 2 shows thetypical values of temperature at different parts of acast iron piston. It may be noted that the maximumtemperature occurs at the centre of the crown anddecreases with increasing distance from the centre.The temperature is the lowest at the bottom of theskirt. [12]Poor design may result in the thermaloverloading of the piston at the centre of the crown.The temperature difference between piston outeredge and the centre of the crown is responsible forthe flow of heat to the ring belt throughout the pathoffered by metal section of the crown. It is thereforenecessary to increase the thickness of the crownfrom the centre to the outer edge in order to make apath of greater cross-section available for theincreasing heat quantity.The length of the path should not be toolong or the thickness of the crown cross-section toosmall for the heat to flow. This will cause thetemperature at the centre of crown to build up andthereby excessive temperature difference between
  2. 2. Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Applications (IJERA) ISSN: 2248-9622www.ijera.com Vol. 3, Issue 3, May-Jun 2013, pp.1402-14071403 | P a g ethe crown and the outer edge of the piston willresult. This may even lead to cracking or pistonduring overload operation.Fig. 2 Piston Temperature distributionsThere are many technical contributionpublished in IC engines field, mainly for the pistonand piston ring dynamics. The modeling of pistonand piston ring for primary and secondary motion,especially FE models with 3D approach have beenused to study the secondary motion.Ouk Sub Lee, Hyebin Choi and HongMinKim [1] has carried the work to investigate thedynamic deformation of two aluminum alloy, resultsobtained by considering stresses due to temperatureat front-end and back-end of the specimen. Theeffect of contact time at high temperature is notedearly deformation. The strain rate and the hightemperature significantly affect the plastic flowbehavior. The effect of temperature on plastic flowincreases at high temperatures and effects seem to bemore pronounced than that of the increases strainrates.The Dongfang Bai [2] in Sloan AutomotiveLaboratory, Massachusetts Institute of Technologyhas been involved in solving piston secondarymotion of IC engine by developing a numericalmodel, with both cavitations & piston skirtdeformation taken into consideration. As the loadand correspondingly the side force are large, thepiston skirt will have very large deformation andhence result in a lateral position. HirotakaMurakami, Narutake Nakanishi, Naoto Ono andTomoharu Kawano, [3] have developed a new pistonsecondary motion analysis that accurately predictspiston strength and piston slap, that occurs when theengine is running. Z. Geng and J.Chen [4] has beeninvolved in the investigation of piston slap inducedvibration for engine condition. P. Gustof, A. Hornik[5] has been involved to find out the influence of theengine load on value and temperature distribution inthe piston of the turbocharged Diesel engine. Theresults of calculations of the temperature distributionin the piston of the turbocharged diesel engine independence from the engine loads were received bymeans of the two – zone combustion model and thefinite element method. Zuoqin Qian, Honghai Liu,Guangde Zhang, and David J. Brown[6] hasinvolved in Temperature Field Estimation for thePistons of Diesel Engine 4112 using the combinationof experimental measurement and finite elementanalysis (FEA). The experimental results show thatthe temperatures of pistons and liners on the samecircle are different as the circle area changes, whichis caused by their local over-high heat loads. Dr. S.NKurbet [7] et al was presented the results by finiteelement study of piston ring, under assembly load interms of induced stress and ring gap. The studyincluded the stress analysis at the interface betweenthe coating and substrate of ring for various laydesign. Information from the analysis would serve toreduce the design performance testing cycle time &be useful in the development of coating techniques.The finite element and piston transverse movementcalculation technique is satisfactorily used to predictengine vibrations and noise due to piston slap. C.D.Rakopoulos, D.C. Rakopoulos, G.C. Mavropoulos,E.G. Giakoumis [8] have been involved inestimation of cylinder wall transient temperaturecylinder walls of a diesel engine at various operatingconditions. Ali Sanli, Ahmet N. Ozsezen, IbrahimKilicaslan, Mustafa Canakci [9] have studied theheat transfer characteristics between gases and in-cylinder walls at fired and motored conditions in adiesel engine were investigated by using engine dataobtained experimentally. Dr. Ahmed A, Dr. Basim[10] has worked to study the Thermal effects ondiesel engine piston and piston compression ring.The conclusion has came to know fromabove literature survey are as, many works havebeen carried out to study the causes of piston slapand piston distortion. The result analysis gives theforce exerted by the gas over the piston is the majorsource which causes the piston slap. Also manyworks have been carried to study effect of pistonslap on lubrication. Due to combustion of fuelenormous heat will be released in engine cylinder.This thermal load will be absorbed by the piston andother components of the engine. The effect of theengine operating conditions, viz., load on the enginekeeping speed of the engine constant, the heatrelease in the cylinder, heat absorbed by the piston,have been discussed and found that increase inengine load at constant speed has a major effect onthe peak heat fluxes and heat transfer coefficientsover the combustion chamber wall surfaces. Theeffect of contact time at high temperature is notedearly deformation. The strain rate and the hightemperature significantly affect the plastic flowbehavior.The objective of the present work is to findout the contribution of thermal load in piston slapand piston deformation. For the purpose it isnecessary to conduct an experiment to find out thepiston position inside the cylinder and also toestimate the piston cylinder gap. Analytical
  3. 3. Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Applications (IJERA) ISSN: 2248-9622www.ijera.com Vol. 3, Issue 3, May-Jun 2013, pp.1402-14071404 | P a g ecalculations are done to find out the piston crowntop surface temperature for which the experimentaldata is used. The other intention is to know thetemperature distribution over the piston and to findout the piston deformation from the finite elementanalysis to correlate the effect of temperature onpiston deformation. To find out the lateral motion ofpiston in terms of the gap between cylinder andpiston, to predict the effect of piston deformation forpiston slap and hence the vibration of the engine.II. Description of IC EngineThe specifications of the single cylindervertical diesel engine are shown in Table 1.Table 1. Diesel engine specificationsSl.NoDescription Specification1 Engine make Kirloskar diesel engine2 Bore 80 mm3 Stroke 110mm4Engine speed takenfor study1500 rpm5 Compression ratio 16.5:16 Test condition/TypeWater cooled direct injectiondiesel single cylinder engine7Max pressure atstudy rpm54 barsThe material properties of the piston of the cylinderare shown in the Table 2. The observations of test rigare made and are listed in Table 3.Table 2. Material propertiesPart pistonMaterial Aluminum alloyDensity (Kg/m3) 2630Youngs modulus (MPa) 72400Coefficient of Thermal Expansion(/oC)2.3×10-5Poison’s ratio .31Table 3. Test rig observationsIII. Analytical calculations:1) Air is considered as ideal gas, from idealgas the isentropic compression is given by[13]2) Heat release by the combustion is given by,Q = mf * LHV (low heat value of fuel) [8,11]3) Stoichiometric combustion equation of fuel[8.11]C12H23 + 18.5(O2 + N2) →12CO2 + 13H2O+ 43.167N24) Mass fraction,[8,11]5) After combustion to find the gastemperature,[8,11]= ( )6) Woshni’s equation for heat transfercoefficient to calculate the cylinder walltemperature,[9,12]The average gas velocity,Where and are constants, = 2.38 and =3.24 10-3Velocity of the piston is given by,7) To estimate cylinder wall temperature,8) The piston crown top surface temperature isgiven by,The 3D geometric model of the piston isdeveloped using the dimensions of the Kirloskarengine piston using CATIA V5 modeling softwareand is shown in Figure 3. This model is thenimported to ANSYS software to carry out finiteelement analysis.Fig. 3 Piston modelLoad 11.26 N-mSpeed 1464 rpmFuel Rate 1.38 kg/HrAir Rate 22 m3/HrWater Flow 37.7 cc/sectw1, water inlet to Calorie meter 39.7 Ctw2, water outlet from Engine Jacket 34.7 Ctw3, water outlet from Calorie meter 55.9 Cte4, exhaust Gas inlet to Caloriemeter199 Cte5, exhaust Gas outlet from Caloriemeter190.8 Ct1, ambient Temperature 36.1 CAir Fuel Ratio, AFR 17.87Load 11.26 N-mSpeed 1464 rpm
  4. 4. Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Applications (IJERA) ISSN: 2248-9622www.ijera.com Vol. 3, Issue 3, May-Jun 2013, pp.1402-14071405 | P a g eIV. Result and discussions:The Table 4 shows the result obtained bythe analytical calculations using empirical relationsused in calculation in above section.Table 4. Analytical resultsExperiment has been carried on the singlecylinder diesel engine for load condition of 11.6 Nand observed for 10 minutes. The Figure 4 showspressure (P) verses crank angle in degrees (θ). Thepeak pressure reached to 36 bar at 367° crank angle.Pressure in the suction stroke is remain zero andwhen the piston starts to move in compression strokethe pressure at 336° crank angle starts to increase.Around 352° crank angle the pressure start todecrease and later at 360° crank angle again pressurestarts to increase. This is due to preparation periodfor combustion after the fuel injection called delayperiod. Therefore the motoring pressure isconsidered as 16 bar around 352° crank angle. Whenthe piston starts to move in expansion stroke the willdecreases 368° crank angle and reaches to initialpressure zero.Crank angle in degreesFig. 4 Pressure verses crank angle graphFrom the P-θ graph (Figure 4) it is notedthat, the peak pressure, P = 36 bar and motoringpressure, Pm = 16 bar are at 352° crank angle. Hencechange in pressure, ΔP = P - Pm. The experiment hasbeen carried out by applying the load of 11.26 N-mby using the electric dynamometer. The first data hasbeen logged after running the engine for first fiveminutes and the second data has been logged afterrunning the engine for ten minutes. The pistonposition and piston-cylinder gap inside the cylinderis noted by plotting the piston-cylinder gap versestime graph as shown in Figure 5 (a) and (b).Fig. 5 (a) Piston cylinder gap (for 5 min)Fig. 5 (b) Piston cylinder gap (for 10min)It is clear from the Figure 5. that the pistonslap occurs in between 0.0099 sec and 0.0114 sec,0.02844 sec and 0.0297 sec, 0.0494 sec and 0.0537sec and 0.0666 sec and 0.0262 sec. About 18microns to 24 microns there is film lubrication of oilfrom the cylinder wall and when the piston is atcentre line axis then 204 microns of gap between thepiston and the cylinder is noted. The finite elementanalysis is carried out to know the piston behaviordue to the thermal load acted upon it by thecombusted gas. The Figure 6 shows the temperaturedistribution over piston.Fig. 6 Temperature distributionMass flow rate of fue for onecyclel, mf3.006× 10-5kg/sVolumetric flow rate of air 22 m^3/hrMass flow rate of air for onecycle , ma5.69 × 10-4kg/ sTemperature at the end ofcompression stroke, T2948.31KHeat release by the combustionfor one cycle, QQ = 1303 J/ sTemperature of the gas, Tg Tg = 1142.82KHeat transfer coefficient forone cycle, h97.30 w/m2KCylinder wall temperature, Tw 657.65 KPiston crown temperature, Tp 567.52K
  5. 5. Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Applications (IJERA) ISSN: 2248-9622www.ijera.com Vol. 3, Issue 3, May-Jun 2013, pp.1402-14071406 | P a g eThe highest temperature distribution isobserved ranging from 285.74oC to 294.9oC at thecrown and the skirt temperature distribution isranging from 166.42oC to 258.21oC. So the pistoncrown absorbs more heat from the gas, which isdirectly in contact with the hot gases.The thermal load is imported in structuralanalysis for analyzing the piston directionaldeformation and the stresses developed due to thethermal load. The piston deformation is analyzed inz-direction of piston thrust side. It has been noted inthe Figure 7, that the maximum deformation value263 microns is at the piston crown and the minimumdeformation at the skirt is 28 microns in z-direction.The Figure 8 shows the distribution of thermalstresses over the piston. The maximum thermalstress distribution is ranging from 62MPa to69.788MPa and 54.323MPa to 62MPa noted at innerside oil ring land and at the centre of the pistonbowl. The second and third piston land is muchexposed to the thermal stresses, but the piston skirthas minimum value thermal stresses ranging from.19MPa to 16.661MPa.Fig. 7 Piston deformation in z-directionFig. 8 Thermal stresses over the pistonThe piston cylinder gap verses time graphsfor five minutes engine run and for ten minutesengine run are combined and plotted with referenceto gap in microns and crank angle in degrees isshown in the Figure 9. When the piston starts tomove between TDC to BDC due to eccentricity ofcrank shaft piston will tilt and slap to the one side ofcylinder, which will be on thrust side.Fig. 9 Piston cylinder gap comparison graph 3It has been noted clearly that piston slapoccurs in-between the 77.4 and 99 degrees of crankangle in the suction stroke, 258 and 280.8 degrees ofcrank angle in the compression stroke, 432 and453.6 degrees of crank angle in the expansion strokeand 617.1 and 635 degrees of crank angle in theexhaust stroke. It is observed, when piston axiscoincides with the cylinder axis the gap betweenpiston and cylinder is 204 microns and when pistontilts the gap is about 18 microns to 24 microns whichaccounts the film thickness of the lubricating oilbetween the cylinder wall and piston skirt. This willrepeat for the remaining cycles.In the Figure 9, it is observed that after runningthe engine for 10 minutes there is change in pistondiameter about 6 microns, this is due to the loadabsorbed by the piston for combustion. When pistonwill absorb, the geometry diameter has increased andit has confirmed by the experimental investigationon the present engine.The FE analysis is done to analyze thepiston deformation due to the thermal load. Theanalysis is done for 100 seconds and the deformationis noticed in the z-direction towards the thrust sideof piston. . The maximum deformation value 263microns is at the piston crown and the minimumdeformation at the skirt is 28 microns in z-direction.The designed piston cylinder gap is 204 microns andthe change in piston diameter is about 6 microns. Sothat the designed piston considered for the analysishas lesser deformation values than the FE analysismodel and so the designed piston for the analysis ofpiston deformation and piston slap is correct. Thedirectional deformation in the piston for the givengas pressure is proportional to the variation of thegap between the cylinder liner and the piston. Thesecondary motion of the piston is considered by thez-directional deformation which is measured here bythe gap between cylinder liner and the piston.
  6. 6. Vinay V. Kuppast, Dr.S.N.Kurbet, H.D Umeshkumar, Adarsh B.C / International Journal ofEngineering Research and Applications (IJERA) ISSN: 2248-9622www.ijera.com Vol. 3, Issue 3, May-Jun 2013, pp.1402-14071407 | P a g eV. ConclusionsThe secondary motion of the piston isconsidered as the main source for the piston slap,which in turn causes the impact on the cylinder wallsresulting in engine vibration and noise. In thepresent study, the geometric three dimensionalmodel of the piston is developed and is used for theFE analysis for the thermal boundary conditionswhich are calculated by using the experimental dataof the engine in running condition and by using theempirical relations.Thermal stresses and deformation in thepiston reduces the gap between the cylinder liner andthe piston, which increases in the diameter of thepiston and influences impact on the cylinder. Gapbetween the cylinder liner and the piston whichindicated the lateral motion of the piston fordifferent crank angle motion of the piston from TDCto BDC is measured.The FE analysis of the piston revealed thatthe thermal stresses induced in the piston areproportional to the directional deformation. The z-directional deformation is proportional to the lateralmotion of the piston, which is represented by the gapbetween the cylinder liner and the piston. This resultagrees with the results obtained from the FE analysisand hence the FE results can consideredconveniently for the prediction of the enginevibration and noise.Piston material and geometry can beoptimized to lower the NVH, by maintaining thethermal efficiency unaltered. This approach canconsiderably cut down the time and cost ofexperiments in the design phase of the engine tooptimize the engine parameters for lowenvironmental pollution.ReferencesJournal Papers:[1] O.S. Lee, HongMin Kim and HeyBinChoi., “High temperature dynamicdeformation of aluminum alloys usingSHPB by mechanical science andtechnology”, 2011.[2] Dongfang Bai., “Solving Piston SecondaryMotion of Internal Combustion Engines”,Sloan Automotive Laboratory,Massachusetts Institute of Technology.[3] Hirotaka Murakami, Narutake Nakanishi,Naoto Ono and Tomoharu Kawano., “NewThree dimensional piston secondary motionanalysis method coupling structure analysisand multi body dynamics analysis” JSAE20119559 / SAE 2011-32-0599.[4] Z. Geng, J.Chen., “Investigation into pistonslap induced vibration for engine conditionsimulation and monitoring”, Journal ofSound and Vibration 282, 2005.[5] P. Gustof, A. Hornik., “The influence of theengine load on value and temperaturedistribution in the piston of theturbocharged Diesel engine”, Journal ofAchievements in Materials andManufacturing Engineering. AMME,Received 16.02.2009; published in revisedform 01.08.2009.[6] Zuoqin Qian, Honghai Liu, Guangde Zhangand David J., “Temperature FieldEstimation for the Pistons of Diesel Engine4112” Journal of Wuhan TechnologyUniversity, 2005.[7] Dr. S.N.Kurbet and R.Krishnakumar ., “AFinite Element study of Piston Tilt effectson Piston Ring Dynamics in IC Engines”,Proc Instn Mech Engrs (IMECHE) PartK.2004, pp 107-117”.[8] Mahdi Hamzwhei and Manochehr Rashidi.,“Determination of Piston and CylinderHead Temperature Distribution in a 4-Cylinder Gasoline Engine at ActualProcess”, Proceedings of the 4th WSEASInt. Conf. on heat transfer, thermalengineering and environment, Elounda,Greece, August 2006.[9] C.D. Rakopoulos, G.C Mavropoulos.,”Experimental and theoretical study of theshort term response temperature transientsin the cylinder wall of a diesel engine atvarious operating conditions”, Appliedthermal engineering 24, 2004.[10] Ali Sanli, Ahmet N Ozsezen, IbrahimKilicaslan., ”The influence on engine speedand load on the heat transfer between gasesand in cylinder walls at fired and motoredconditions of an IDI diesel engine”,Applied thermal engineering 28, 2008.[11] Dr. Ahmed A, Dr. Basim., “Thermal effectson diesel engine piston and pistoncompression ring”, Engineering andtechnology Journal, Vol. 27, No. 8, 2009.Books:[12] V. Ganesan., “Internal combustionengines”, Tata McGraw-Hill Publications.[13] John.B. Heywoob., ”Internal combustionengines: Applied Thermo sciences”, JohnWiley and Sons.[14] P.K. Nag,”Engineering Thermodynamics”,Tata McGraw-Hill Publications.

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