International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 09766340(Print), ISSN 0976 – 6359(Online) Vol...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 09766340(Print), ISSN 0976 – 6359(Online) Vol...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 09766340(Print), ISSN 0976 – 6359(Online) Vol...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
Upcoming SlideShare
Loading in...5
×

Analysis of engine cooling waterpump of car & significance of its

726

Published on

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
726
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Analysis of engine cooling waterpump of car & significance of its

  1. 1. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME100ANALYSIS OF ENGINE COOLING WATERPUMP OF CAR &SIGNIFICANCE OF ITS GEOMETRYBhavik M.Patel1, Ashish J. Modi2, Prof. (Dr.) Pravin P. Rathod31(PG Student, Mechanical Engineering Department, Government Engineering College, Bhuj)2(Assistant Professor, Mechanical Engineering Department, Government EngineeringCollege, Bhuj)3(Associate Professor, Mechanical Engineering Department, Government EngineeringCollege, Bhuj)ABSTRACTTo study behaviour of flow in cooling water pumps, we done extensive search andgone through numerous research paper and blogs.We found that many researchers carried outtheir analysis on other cooling system components like radiator, cooling water jacket andfans. But it is very difficult to find researchers worked on cooling water pumps. Howevercooling system consists of centrifugal pump which is widely used in other industry. Afterreviewing all research paper on centrifugal pumps we found that most of the problems arerelated to cavitationand low efficiency.Some researchers give importance to improvement ofblade angle and blade design to reduce cavitation effect while some researches concentrateson efficiency of the pump irrespective of cavitation effect mostly in the industry wherecavitation effect is negligible. After analyzing some old water pumps of various vehicles wefound that major problem that pump is facing is due to cavitation effect on blades at HighRPM. This research is aimed to analyze the role of centrifugal water pump in automobileengine cooling system and to obtain relation between pump geometry and pump flowcharacteristics.Keywords: Water pump, Engine cooling system, simulation, CFD, ANSYS, Cooling waterpump Geometry, cavitation, coolant flow, flow characteristicsINTERNATIONAL JOURNAL OF MECHANICAL ENGINEERINGAND TECHNOLOGY (IJMET)ISSN 0976 – 6340 (Print)ISSN 0976 – 6359 (Online)Volume 4, Issue 3, May - June (2013), pp. 100-107© IAEME: www.iaeme.com/ijmet.aspJournal Impact Factor (2013): 5.7731 (Calculated by GISI)www.jifactor.comIJMET© I A E M E
  2. 2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME101INTRODUCTIONAutomobile Cooling pump is the key part of the Automobile cooling system that keepcirculate the coolant throughout it and takes away excess heat from engine at different Enginerpm and torque conditions. Also its surrounding atmospheric conditions can vary coolantcharacteristics. This research involves the investigations on the existing coolant pump of car(Maruti SUZUKI Alto), to understand the flow characteristics. The research is carried out inthree approaches to understand the behavior of fluid. The first one is "Theoretical approach"in which Empirical relations are used. It describes how the desired pump operatingparameters such as flow rate, specific speed of pump etc. can be derived. It also describes thecoolant characteristics & understanding of flow characteristics in the closed, pressurizedautomobile cooling system. The another one is "Practical approach" in which flow rate andfluid pressure of pump flow are measured on existing coolant pump of Maruti SUZUKI Altoat different engine rpm. The third approach involvesthe “Computational Fluid Dynamics" ofpump flow, which itself provides graphical representation of the relations between flowcharacteristics and pump geometry. The "Result discussion" section provides brief discussionon the results which are derived after these three approaches.THEORITICAL APPROACHBelow steps has been carried out to obtain desired coolant flow rate.• Obtained heat rejection data for specific engine model and rating. This information isavailable from the engine technical data sheet. Maximum heat rejection (nominal +tolerance) values are used.• Obtained density and specific heat values for coolant. Table 1 provides these valuesfor the specific coolant.• Using these values in Empirical equations we can calculate coolant flow rate asbelow.Heat Rejection by Engine CalculationBefore a coolant flow rate can be calculated, we must calculate how much heat isbeing rejected through the engine. The heat input to the engine equals the sum of the heat andwork outputs. From following equation, heat input values are derived with the use of Power -Torque - Speed curve. As per SAE papers, the total heat output of engine is the sum of totalexhaust heat, heat loss to the surroundings, total heat dissipated by engine coolant and totalheat dissipated by engine oil. It is also assumed that approximately one third of total heatoutput is equal to the total heat dissipated by the engine coolant. The total heat input can becalculated as follows:Heat input to engineሺKWሻ ൌBrake PowerሺBPሻ ൈ 100Thermal Efϐiciencyሺ%ሻ
  3. 3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 09766340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, MayCoolant Flow CalculationThe coolant flow required for different heat load from the enginecan be calculated using the following equation:Power - Engine RPM - Torque CurveSAE 2001 paper states that conventional coolant flow rate on smaller engines withmechanically driven water pumps vary between 2.0 to 2.6 L/min/Kw. The flow rate derivedfrom the above equation falls under this criteria.curve based on above equations.Specific SpeedSpecific speed is a number characterizing the type of impeller in a unique and coherentmanner. Specific speed are determined independent of pumcomparing different pump designs. The specific speed identifies the geometrically similarityof pumps.Typical values for specific speed• radial flow - 500 < Ns< 4000vanes - double and single suction. Francis vane impellers in the upper range• mixed flow - 2000 < Ns< 8000pumps• axial flow - 7000 < Ns< 20000By calculation, the specific speed value falls between 1000condition. So it suggestsusing radial vane impeller pump and thecars also proves true that the car coolant pumps are centrifugal pumps with radialInternational Journal of Mechanical Engineering and Technology (IJMET), ISSN 09766359(Online) Volume 4, Issue 3, May - June (2013) © IAEME102The coolant flow required for different heat load from the engine components to the radiatorscan be calculated using the following equation:Torque CurveRequired Pump RPM - Pump Flow Rate CurveSAE 2001 paper states that conventional coolant flow rate on smaller engines withmechanically driven water pumps vary between 2.0 to 2.6 L/min/Kw. The flow rate derivedunder this criteria. Graph 1 represents Pump rpm v/s flow rateSpecific speed is a number characterizing the type of impeller in a unique and coherentmanner. Specific speed are determined independent of pump size and can be usefulcomparing different pump designs. The specific speed identifies the geometrically similarityTypical values for specific speed - Ns - for different designs in US units (US gpm, ft)< 4000 - typical for centrifugal impeller pumps with radialdouble and single suction. Francis vane impellers in the upper range< 8000 - more typical for mixed impeller single suction< 20000 - typical for propellers and axial fanspeed value falls between 1000-2000 under different operatingradial vane impeller pump and the actual pump used in existingcar coolant pumps are centrifugal pumps with radial00.10.20.30.40.50.60.70.80 2000PumpFlowRate(Kg/s)Pump RPMInternational Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –June (2013) © IAEMEcomponents to the radiatorsPump Flow Rate CurveSAE 2001 paper states that conventional coolant flow rate on smaller engines withmechanically driven water pumps vary between 2.0 to 2.6 L/min/Kw. The flow rate derivedPump rpm v/s flow rateSpecific speed is a number characterizing the type of impeller in a unique and coherentp size and can be usefulcomparing different pump designs. The specific speed identifies the geometrically similarity(US gpm, ft)typical for centrifugal impeller pumps with radialdouble and single suction. Francis vane impellers in the upper rangemore typical for mixed impeller single suctionunder different operatingactual pump used in existingcar coolant pumps are centrifugal pumps with radial vanes.2000 4000Pump RPM
  4. 4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME103Typical Coolant CharacteristicsThe engine’s cooling system is designed to meet specific guidelines. The propercoolant/antifreeze will provide the following functions:• Adequate heat transfer• Compatibility with the cooling system’s components such as hoses, seals, and piping• Protection from water pump cavitation• Protection from other cavitation erosion• Protection from freezing and from boiling• Protection from the build-up ofcorrosion, sludge, and scaleFollowing graph represents the Engine coolant saturation pressure at different fluidtemperature. Though cavitation is the phenomenon of "constant temperature boiling due tolow pressure" that is due to sudden increase in the fluid velocity at pump inlet when impellersuck the fluid so there is sudden pressure drop of fluid. Table 1 show the coolant propertieswhen the fluid temperature is 80 deg. C.Engine Coolant Saturation Pressure in psi Table 1Pump Flow CharacteristicsPump inlet pressure is higher compare to saturation pressure at different temperature toreduce cavitation effect at inlet side.The cooling system and its components must meet both criteria.A) Maximum pressure design limits. At any point in the cooling system that exceed themaximum pressure for the local components such as radiators etc. andB) The minimum pressure at any location in the cooling system shall not fall below the vaporpressure of the coolant to prevent low pressure boiling. A minimum pressure/head is alsorequired at the pump inlet to avoid cavitation, minimize metal erosion and noise.Coolant Property Value withUNITMolar Mass 0.07343 Kg/molDensity 1.03 Kg/m^3Specific Heat 3579.71 J/Kg*KThermalConductivity0.4153 W/m*KDynamic Viscosity 2.8 Centipoise0510150 20 40 60 80 100 120SaturationPressure(psi)Temp in deg. C
  5. 5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME104PRACTICAL APPROACHAfter determining the required coolant flow rate, pump performance establishes themaximum allowable external resistance. Piping and heat transfer equipment resist water flow,causing an external pressure head which opposes the engine driven pump. The water flow isreduced as the external pressure is increases. The total system resistance must be minimizedin order to ensure adequate flow. A cooling system with excessive external pressure headswill require pumps with additional pressure capacity. With Practical approach, the pressuredrop in the fluid flow can be measured by totaling the pressure drop in each of the systemscomponents.CFD ANALYSIS OF ENGINE COOLING WATER PUMPDefine GoalsFrom theoretical and practical approach, pump design parameter are obtained which affectsthe pump flow characteristic. To study pump flow characteristic, Ansys CFX is used whichwill provide results with graphical representation of flow characteristic like pressure,velocity, mass flow rate etc. at different location of pump.Flow Geometry and Mesh CreationThe pump model geometry is complex and asymmetric due to the blade and volute shape.The 3D CAD software was usedto extractpump fluid profile geometry from pump modelThepump model specification is given bellow in table 3. An Optimized mesh is used for analysis.The model is divided into twodomains i.e. rotating and stationary.
  6. 6. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 09766340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, MayMesh - Stationary andIdentify Domain and Boundary ConditionIn steady state type analysis,& Stationary. The rotating domain includes the fluid profile whichimpeller while the rest of the fluid region is defined asdefined for the fluid flow at impeller inlet, impeller outlet, Inlet and outlet of pump withGeneral connection and conservatmixture of Ethylene Glycol & water is defined with required properties for the solverequation in material library. The mainvestigated for cavitation effect in pumpImpeller SpecificationHub Dia 19.35 mmImpeller Outside Dia 56 mmSuction Dia Impeller ODFlow Type Radial FlowBlade Type Circular 2DNo of Blade 7 (CCW)Total Height 23.47 mmInternational Journal of Mechanical Engineering and Technology (IJMET), ISSN 09766359(Online) Volume 4, Issue 3, May - June (2013) © IAEME105Pump Geometry 1tationary and Rotating domain of pump flowBoundary ConditionIn steady state type analysis, Non Buoyant, two fluid domains are definedrotating domain includes the fluid profile which is in contact with theest of the fluid region is defined as Stationary domain. Interfaces aredefined for the fluid flow at impeller inlet, impeller outlet, Inlet and outlet of pump withGeneral connection and conservative interface flux in fluid flow.Engine coolant, a 50/50 %mixture of Ethylene Glycol & water is defined with required properties for the solverThe mass transfer model is set to cavitation and the results areeffect in pump at different pump rpm.19.35 mm56 mmImpeller ODRadial FlowCircular 2D7 (CCW)23.47 mmInternational Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –June (2013) © IAEMEtwo fluid domains are defined - Rotatingin contact with theStationary domain. Interfaces aredefined for the fluid flow at impeller inlet, impeller outlet, Inlet and outlet of pump withEngine coolant, a 50/50 %mixture of Ethylene Glycol & water is defined with required properties for the solverand the results are
  7. 7. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 09766340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, MayRESULTAbove results shows contour plots of velocity and pressure on different planes. Below graphshows flow rate vs. head at different engine RPM. By carefully studying each case, it can beconcluded that at very low RPM, flow is turbulent. Alsocavitation is achieved at medium engine speed.SIGNIFICANCE OF PUMP GEOMETRYA common misconception about cooling systems is that if the coolant flows tooquickly through the system, it will not have time to cool properly.cooling systems are a closed loop, coolant allowed to stay in the radiator longer will alsostay in the engine block longer producing increased coolant temperatures. This caneasily lead to ‘hot spots’ and ultimately, engine failure.increases velocity by reducing pressure with providing sudden reduction in cross seat outlet of pump. Sudden reduction also result into turbulent flow at the outlet whichcontradictory helps in maintaining engine block temperatures which we canabove results also.However turbulent flow at inlet leads to less pumpbelow vapor pressure of coolant then it leads to pump cavitation. From above results we canconclude that venturi effect at the inlet of the pump helps in avoiding cavitation by increasinginlet fluid pressure above vapor pressure at normal speedInternational Journal of Mechanical Engineering and Technology (IJMET), ISSN 09766359(Online) Volume 4, Issue 3, May - June (2013) © IAEME106024680 20 40HEAD(ft)FLOW RATE (GPM)3000 RPM 2625 RPMAbove results shows contour plots of velocity and pressure on different planes. Below graphshows flow rate vs. head at different engine RPM. By carefully studying each case, it can beconcluded that at very low RPM, flow is turbulent. Also best pump efficiency with lesscavitation is achieved at medium engine speed.GEOMETRYA common misconception about cooling systems is that if the coolant flows tooquickly through the system, it will not have time to cool properly. Because automotivecooling systems are a closed loop, coolant allowed to stay in the radiator longer will alsostay in the engine block longer producing increased coolant temperatures. This caneasily lead to ‘hot spots’ and ultimately, engine failure. To avoidthesecentrifugal pumpvelocity by reducing pressure with providing sudden reduction in cross seat outlet of pump. Sudden reduction also result into turbulent flow at the outlet whichcontradictory helps in maintaining engine block temperatures which we canHowever turbulent flow at inlet leads to less pump efficiency and also if pressure fallslow vapor pressure of coolant then it leads to pump cavitation. From above results we caneffect at the inlet of the pump helps in avoiding cavitation by increasingapor pressure at normal speed and decreasing velocity of fluid.International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –June (2013) © IAEME60FLOW RATE (GPM)2250 RPMAbove results shows contour plots of velocity and pressure on different planes. Below graphshows flow rate vs. head at different engine RPM. By carefully studying each case, it can bebest pump efficiency with lessA common misconception about cooling systems is that if the coolant flows tooBecause automotivecooling systems are a closed loop, coolant allowed to stay in the radiator longer will alsostay in the engine block longer producing increased coolant temperatures. This cancentrifugal pumpvelocity by reducing pressure with providing sudden reduction in cross section areaat outlet of pump. Sudden reduction also result into turbulent flow at the outlet whichcontradictory helps in maintaining engine block temperatures which we can see throughefficiency and also if pressure fallslow vapor pressure of coolant then it leads to pump cavitation. From above results we caneffect at the inlet of the pump helps in avoiding cavitation by increasingand decreasing velocity of fluid.
  8. 8. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME107CONCLUSIONThe summary of the present research paper as follows1. By studying different design points carefully it can be concluded that the existingpump of Alto car is designed for best performance at normal car speed. Pumpgeometry at inlet (venturi effect) avoids cavitation phenomenon and increase pumpefficiency significantly.2. However at low and high speed of car, pump is subject to more cavitation. So there isscope to improve that.3. Sudden reduction at pump outlet is observed in existing pump, which is generally tobe avoided while designing the pump. But it helps in avoiding hot zones by increasingvelocity and making flow turbulent.REFERENCES[1] Rodrigo Lima Kagami, Edson LuizZaparoli, Cláudia Regina de Andrad, “ Cfd Analysisof An Automotive Centrifugal Pump”, 14th Brazilian Congress of Thermal Sciencesand Engineering, October18-22, 2012[2] Munish Gupta, Satish Kumar, Ayush Kumar, “Numerical Study of Pressure andVelocity Distribution Analysis of Centrifugal Pump”, International Journal of ThermalTechnologies, ISSN 2277 – 4114,Vol.1, No.1 (Dec. 2011) ,pp-118-121.[3] R.Ragoth Singh, M.Nataraj “Parametric Study and Optimization of Centrifugal PumpImpeller by Varying The Design Parameter Using Computational Fluid Dynamics: PartI”, Journal of Mechanical and Production Engineering (JMPE) ISSN 2278-3512 Vol.2,Issue 2, Sep 2012 ,pp-87-97[4] E.C. Bacharoudis, A.E. Filios, M.D. Mentzos1 and D.P. Margaris,“Parametric Study ofa Centrifugal Pump Impeller by Varying the Outlet Blade Angle”, The OpenMechanical Engineering Journal, 2008, 2, pp-75-83[5] Mohammed Khudhair Abbas “Cavitation In Centrifugal Pumps”, Diyala Journal ofEngineering Sciences, ISSN 1999-8716, 22-23 December. 2010, pp. 170-180[6] AbdulkadirAman, SileshiKore and Edessa Dribssa ,“Flow Simulation and PerformancePrediction of Centrifugal Pumps Using CFD-Tool”, Journal of EEA, Vol. 28, 2011,pp-59-65.[7] Weidong Zhou, Zhimei Zhao, T. S. Lee, and S. H.Winoto ,“Investigation of FlowThrough Centrifugal Pump Impellers Using Computational Fluid Dynamics”,International Journal of Rotating Machinery, 9(1): 49–61, 2003,pp-49-61.[8] S.Rajendran and Dr.K.Purushothaman,“Analysis of a Centrifugal Pump Impeller UsingANSYS-CFX”, International Journal of Engineering Research & Technology (IJERT)Vol. 1 Issue 3, May – 2012,ISSN: 2278-0181,pp-1-6.[9] http://www.engineeringtoolbox.com/specific-speed-pump-fan-d_637.html[10] Manish Dadhich, Dharmendra Hariyani and Tarun Singh, “Flow Simulation (Cfd) &Fatigue Analysis (Fea) of a Centrifugal Pump”, International Journal of MechanicalEngineering & Technology (IJMET), Volume 3, Issue 3, 2012, pp. 67 - 83, ISSN Print:0976 – 6340, ISSN Online: 0976 – 6359.[11] Kapil Chopra, Dinesh Jain, Tushar Chandana and Anil Sharma, “Evaluation of ExistingCooling Systems for Reducing Cooling Power Consumption”, International Journal ofMechanical Engineering & Technology (IJMET), Volume 3, Issue 2, 2012,pp. 210 - 216, ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359.

×