Performance Analysis of savonius hydro turbine using CFD simulation

Niteen Choudhary1 , Purushottam Sahu2 , Ghanshyam Dhanera3

1Reseach scholar, BM College of Technology, Indore

2Professor and HEAD BM College of Technology, Indore

3 Professors, BM College of Technology, Indore ***

Abstract - The primary goal of this study is to experimentally analyse the turbine's maximum efficiency. The goal of this research is to analyse the performance of a Savonius turbine utilised as a hydro turbine using computational fluid dynamics (CFD) simulations and experimental data. This project is primarily based on the renewable energy system.

Key Words: Fluiddynamics,hydroturbine,modelling,performance,andsimulation,alongwithcomputationalfluiddynamics

1. INTRODUCTION

Thecurrenteraistheeraofenergy.Energycanbeproducedbythewind,tides,sun,geothermalheat,biomass,includingfarmand animalwaste,aswellashumanexcrement,whichisknownasunconventionalenergy.Alloftheseresourcesarerenewableor limitlessanddon'tharmtheenvironment.Additionally,theydon'tdemandheavyuse.Currently,theworldusesupto20,000billion Kwh of energy, of which 70% is generated by conventional sources and the remaining 30% by sources such as hydropower, geothermal,biomass,solar,wind,andatomicenergy.About16%ofthis30%iscreatedthroughthekineticenergyoffallingor streamingwater,whichisthenconvertedintopower.

2. Lift Force Performance Model 3.1

Let'sassumethat(L)istheliftingforce,whichactsinthedirectionofthefluidflow'snormal.Thisisexplicableusingthegoverning equation.

L=1/2C_(L)ρAV^2………………………………………(4.1)WhereAistheareaofthebladeairfoil,istheliftcoefficient,andisthedensity ofwater.PullForceDragforceisthenamefortheforcethatoperatesinthedirectionofflow.Drepresentsthedragforce.Thisforce ismostlycausedbythefluid'sviscosity.ThiscanbestatedusingtheformulaD=1/2AC_d(U-V).^2………………………………(4.2)where speedisV,dragforceisD,fluidvelocityisU,anddragcoefficientisCd.

WherespeedisV,thefluid'svelocityisU,thedragforceisD,andthedragcoefficientisCd.

Typically,theliftanddragcoefficientvaluesareestimatedprovisionallyandcomparedtotheReynoldsnumber.InFig.3.2,aregion ofasharpedgeatspanIisindicated,togetherwiththeassociatedspeeds,powers,andedges.Theedgeoftherelativeliquidspeed totheplaneofrevolutionisdenotedby,andtherelativeliquidvectoratspanrisdenotedbyVrel.LandD,whichareguided oppositeandparalleltotherelatedliquidasappeared,speaktotheresultingliftanddragpowers.

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Fig 3.1 Forces Act on Blade [26]

Forthehighestlevelofskill,carefulconsiderationoftherotoredges'geometryandshapechangeisessential.Despitethefactthat freshairfoilsarerarelymadeforuseonrotors,turbineshavefrequentlyusedairfoilsthatareinspiredbyaeroplanewings.Airfoils usetheconceptofliftratherthandragtoharnessthepoweroftheair.Cuttingedgesthatuselift(powersagainstthedirectionof thestream)aremoreefficientthandragmachines.Ingeneral,usinglifthasresultedinsomebentandalteredshapes.

3. ANALOGOUS SIMULATION- I

Thegeometryforthetwo-bladedSavoniusturbineusedinthisprojectwasdevelopedinSolidWorksandimportedintotheANSYS 15workbench,whereadditionaloperationsincludingmeshingandsimulationswerecarriedout.

Modelling and Grid Size

Thetwobasiccomponentsofthecomputationaldomainarethecoredomainandtheouterdomain.Tworotorswiththeright dimensionsandanappropriateaspectratiomakeupthemaindomain.Here,themotionlessouterdomaincontrastswiththe spinningprimarydomain.Thecomputationaldomain'sgeometryisdepictedinthefollowingfig.

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 10 Issue: 03 | Mar 2023 www.irjet.net p-ISSN: 2395-0072 © 2023, IRJET | Impact Factor value: 8.226 | ISO 9001:2008 Certified Journal | Page1430

Fig 3.2 Forces on the Blade [5]

Parameters Dimensions in mm Diameterofblade(D) 50 Maindomain 110 Aspectratio(e) 5

Table 3.1 Geometry Parameters

3.2 NUMERICAL SIMULATION- II

Therangeoftheaspectratiohasbeenpickedfrom5to25,andanumberofgeometrieshavebeenoptimisedforthisnumerical simulation.AftercreatingallofthegeometryinSolidWorks,itisimportedintoANSYS15foradditionalnumericalsimulation.

Thegeometryofthesamesizewiththesamerotordiameterbutdifferentbladepositionsandproduceaworkablesolution.Inthis case,allofthegeometryiscalculatedusingthesameprocedureasinthepreviouschapter.

Belowfiguresshowthe5differentgeometryhavingdifferentaspectratio.

Results and Discussions

8.3.1 Velocity contour of savonius hydro-turbine at Aspect Ratio e=25 and canal width 0.636D, 2.5D, 5D, and 15D

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Fig 5.1Computational Domain Along With Boundary Conditions[25] Fig6.1SavoniusHydro-TurbinewithPosition Fig6.2SavoniusHydro-TurbinewithPositione=10 Fig 8.7 Velocity Contour at 2.5D Canal Width

Outlet

Interference

Fig 8.8 Velocity Contour at 5D Canal Width

Velocity Inlet Pressure

Bottom Wall Top Wall

Savonius Turbine

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 10 Issue: 03 | Mar 2023 www.irjet.net p-ISSN: 2395-0072 © 2023, IRJET | Impact Factor value: 8.226 | ISO 9001:2008 Certified Journal | Page1432

Fig 8.9 Velocity Contour at 15D Canal Width Fig 8.10 Velocity Contour at 1.25D Canal Width Fig 8.11 Velocity Contour at 0.636D Canal Width 8.3.2 Pressure contour of savonius hydro-turbine at Aspect Ratio e=25 at different canal width Fig 8.12 Pressure contour at 5Dcanal width Fig 8.13 Pressure contour at 15D canal width

Fig 8.14 Pressure contour at 10D canal width Fig 8.15 Pressure contour at 2.5D canal width

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 10 Issue: 03 | Mar 2023 www.irjet.net p-ISSN: 2395-0072

Fig 8.16 Pressure contour at 0.636D canal width

Fig 8.17 Cp Vs Blockage comparison

8.4 Closure

Thefig9.17showshowtheCpisvaryingwithrespecttocanalwidthitisanobviousobservationthatifthecanalwidthistoosmall thetotalforceofwaterwhichiscomingwithafreestreamvelocityisdroppedontherotorandthenwhileincreasingthewidthof theinletareathefluctuationiscontinueandatamiddlepositionabletogettheoptimumCpinthiscasethefeasiblesolutioncanbe abletogetat5D.Thewidthisminimizeatthelastpositionwhereitisunabletorotorfromaboveitisclearlyobservethatwhile reducingthewidthofthecanaltheCpisdecreasinggradually.

TheperformanceofaSavoniushydroturbineCFDsimulationisexaminedinthecurrentworkatlowvelocitiesintherangeof0.6 m/sinsideanopencanal.Forthesamesettings,resultsfrombothexperimentsandCFDworkarecompared.Theresearchresults aresummarisedinthefollowingconclusions:

1. The findings of the torque and power performance measurements of the Savonius hydro turbine indicate that the maximumCpcanbeattainedataspecificlocationwithalowfreestreamvelocitywithlessfluctuationintheturbine.

2. Thelocationdeterminedbythisworkisthemostpracticalsinceitallowsforamaximumpowerco-efficientthatisfar higherthanthatofanyotherposition.

3. Freestreamwatervelocityof0.6m/swouldbeidealforthecurrentworkbecauseitcanbeachievedwithlessfluctuating torqueandpower.

4. Astheoverlapratioincreases,itisseenthattheareasthatcoveralargerpercentageproducehighCpataspecificpoint, whichindicatesthatthepowerextractedthroughaSavoniushydroturbineisincreasinggradually.

5. TheCpisobservedtostartdecreasingate=30astheoverlapratioisfurtherraised,indicatingthate=25isthepractical pointfortheblade.

REFERENCES

[1] N.K. Sarma, A Biswas, R.D. Misra ,“Experimental and computational evaluation of Savonius hydrokineticturbine forlowvelocityconditionwithcomparisontoSavoniuswindturbineatthesameinputpower”Energyconversionand Managementatsciencedirect(2014)

[2] Zied Driss,Olfa Mlayeh Dorra Driss, Makram Maaloul, Mohamed Salah Abis “Numerical simulation and experimental valisation of the turbulent flow around a small incurved Savonius wind rotor” Energy at science direct (2014)

Engineering

Technology (IRJET) e-ISSN: 2395-0056

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Volume: 10 Issue: 03 |

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Fig6.101ComparisonbetweenCpvsTSRwithanaspectratioof5

CONCLUSION

4.

ISO

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| Page1434

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Volume: 10 Issue: 03 | Mar 2023 www.irjet.net

p-ISSN: 2395-0072

[3]PatelC.R.,PatelV.K.,PrabhuS.V.,EldhoT.I.,“InvestigationofOverlapRatioforSavoniusTypeVerticalAxisHydro Turbine”InternationalJournalofSoftComputingandEngineering(IJSCE)ISSN2231-2307,Volume-3,Issue-2,May (2013)

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[8] Mabrouki,ZiedDriss,MohamedSalahAbis,“PerformanceAnalysisofaWaterSavoniusRotorEffectoftheInternal Overlap Ibrahim”Sustainable Energy, 2014, Vol. 2, No. 4, 121-125 Available online at http//pubs.sciepub.com/rse/2/4/1©ScienceandEducationPublishingDOI10.12691/rse-2-4-1

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