ContentslistsavailableatScienceDirect
Sensors and Actuators A: Physical
jo u r n al hom e p a g e :w w w . e l s e v i e r . c o m / l o c a t e / s n a
Multistaging of nonuniform area resonator based fluidic acoustic pump
Sonu K. Thomas
a,∗, Akash B
b, Thiruchengode M. Muruganandam
baDepartmentofMechanicalEngineering,IndianInstituteofTechnology,Madras,Chennai600036,India
bDepartmentofAerospaceEngineering,IndianInstituteofTechnology,Madras,Chennai600036,India
a r t i c l e i n f o
Articlehistory:
Received13June2019
Receivedinrevisedform22October2019 Accepted11November2019
Availableonline14November2019
Keywords:
Acousticcompressor Standingwavepump Fluidicdiodes Multistaging
a b s t r a c t
Feasibilityofmultistagingofanonuniformarearesonatorbasedfluidicpump,bothinseriesaswellasin parallel,isdiscussedincomparisonwithsinglestagepump.Multistaginguptotwostageswascarriedout inthisstudy.Multistagingwassuccessfulinachievinghigherflowratesandhigherbackpressuresthan asinglestagepump.Seriespumpdelivered1.8timesthepressureforzeroflowrate,whereasparallel pumpdelivered2.3timestheflowrateatzerobackpressure.Ofallthreeconfigurations,singlestage pumpwasfoundtohavethebestefficiencybasedontheinputpowerrequirements.Itwasalsofound thattheacousticinteractionsbetweenthestagescanaffecttheperformanceofthepump.
©2019ElsevierB.V.Allrightsreserved.
1. Introduction
Conventional pumps for gases, typically use moving parts, whichhavethedrawbackoffatigueandfailure.Oneofthemajor failingcomponentsisthemechanicalvalveusedinthesepumpsfor flowcontrol.Itisunfavorabletousesuchpumpswherereliabilityis moreimportantthanefficiency.Forinstance,conventionalpumps arehighlyunsuitabledevicesforMEMSapplications[1],handling ofextremelypoisonousandcorrosiveliquids[2,3].Therearemany no-moving-partsvalvesbasedpumps studiedextensively inlit- erature[4–10].Arecentadditiontono-movingpartvalvepump technologyisthevalve-lessstandingwavepump.Nabavietal.[11]
andNabaviandMongeau[12],usedastandingwaveproducedin aresonatorasthesourceforanoscillatoryflowandcombinedit withfluidicdiodesforflowrectification.Asmentionedbefore,flu- idicdiodeswerebeingusedextensivelyinmicro-pumps.Nabavi etal.[11]essentiallyusedthestandingwaveastheactuationmech- anismasopposedtocavitydisplacementasinthecaseofStemme andStemme[13].Moreover,Nabavietal.[11]alsoshowedthatthe pumpedflowrateisproportionaltothestandingwavepeakpres- sure.Thisworkmarkedthebeginningoffluidicacoustic(standing wave)pumps.Initsmostbasicform,fluidicacousticpumpcon- sistsofanactuationmechanismtoestablishastandingwaveina
∗Correspondingauthor.
E-mailaddress:[email protected](S.K.Thomas).
resonator,whereinthepressureoscillationisamplified.Resulting highpressureoscillationisrectifiedusingfluidicdiodes.
Itiswellknownthatforcedoscillationsinsideauniformarea closedduct,ingeneral,cannotattainarbitrarilyhighpeakpressure amplitudesbecauseofshockformation[15,16].Lucasetal.[17]
andLawrensonetal.[18]overcamethislimitationbyusingnonuni- formarearesonators.Theycombinedthesenonuniformresonators withmechanicalvalvestoproducemeanflow. Further,Thomas andMuruganandam[19,20]designedafluidicacousticpumpcom- biningnonuniformresonatorandno-moving-partvalves(fluidic diodes).Theperformanceofthesepumpswillprimarilydependon theshapeofresonatorandthetypeofrectifyingelementsused.
Sincethefrequency ofoperationishighinsuchpumps, simple diffuser/nozzleshapedflowpassagesaregenerallyusedasfluidic diodes.ThomasandMuruganandam[14] gavea comprehensive reviewofsuchacousticpumps,withmoreemphasisgiventothe fluidicaspect.
Asignificantpartoftheversatilityofconventionalpumpsliesin theircapabilitytobemultistaged.Multistagingcanquicklyimprove theperformanceofthefluidicacousticpumpandprovidehigher flowrateorhigherpressurefordifferentapplications.Thiswork exploresifmultistaging canachievea wider rangeof pressures andflowratescomparedtoasinglepump.Inthecaseofacous- ticcompressors,theonlyseriousattempttheauthorscouldfindin publishedacademicliteraturewasbyEl-Sabbagh[21],whereitwas proposedtousedoublecavityplacedbacktobackwithapistonin between.Thisconfigurationcanresultineffectivelyincreasingthe flowrate.SimilararrangementwasdesignedbyKawahashietal.
https://doi.org/10.1016/j.sna.2019.111751 0924-4247/©2019ElsevierB.V.Allrightsreserved.
2 S.K.Thomas,A.BandT.M.Muruganandam/SensorsandActuatorsA301(2020)111751 [22].Anotherattempttowardsmultistagingcanbeseeninapatent
byDooley[23].
Itisclearfromtheliteraturethat,thereishardlyanyworkon multistagingoffluidicacousticpumps.Thepresentworkinvesti- gatesthefeasibilityoftwo multistagedconfigurationsinvolving fluidicacoustic pumps:series and parallel.The performance of thesemultistagepumpsiscomparedtothatofsinglestagepump.
Seriesmultistaging is expectedtoproduce double thepressure ratio,whileparallelconfigurationisexpectedtogivedoublethe flowrateofasinglestagepump.Ambientairwasusedasthework- ingfluidinthisstudy.Compressedairisanimportantmediumfor transportandstorageofenergyacrossarangeofindustrialpro- cesses.Thisworkisexpectedtotakefluidicacousticpumpsastep closertowardstechnologicalfeasibilitybyenhancingtheirperfor- manceandadaptability.
2. Experimentalsetup
Inthissection,thebasicsingleresonatorandthediodecon- figurationare describedfirst.Thenextsubsectionsdescribethe seriesandparallelmultistagepumpconfigurations, followedby instrumentationused.
2.1. Singleresonatorpumpgeometry
Fig.1showstheschematicoftheexperimentalsetupforasingle stagefluidicacousticpump.Astainlesssteelconicalresonatorwith 15mmwallthicknessisdrivenbyaloudspeaker,whichinturn isdrivenbythepoweramplifier.Thespeakersaredrivenatthe fundamentalresonancefrequencyoftheresonatortoestablisha standingwave insidetheresonator.Conicalgeometryischosen owingtoitseaseofmanufacturing.Thegeometryisdescribedby Eqn.(1)
A(x)=(ax+b)2 (1)
where,A istheresonator crosssectional areain mm2,x isthe lengthoftheresonatormeasuredfromitssmallend,a=0.133,b
=17.84mmand0≤x≤200mm.Here,‘a’isrelatedtothedegreeof non-uniformityoftheconeand‘b’givestheradiusatthesmallend oftheresonator(where,x=0).
Apairoffluidicdiodes,oneforinflowandtheotherforoutflowis constructedoutofstainlesssteelconicaldiodeelementsarranged inspecificconfigurations(seeFig.1).Forbetterclarity,onlythe internaldimensionsofthefluidicdiodeareshowninitszoomed view.Fluidicdiodesforinflowandoutflowarethreadedtoaflange atthesmallendoftheconicalresonator.Theinflowdiodeiskept opentotheatmospherewhiletheoutflowdiodewasconnected toapressuretank.Dimensionsofthediodeshavebeenadopted fromtheperformancebasedonpreviousexperimentsonfluidic acousticpump[20].Theoutflowisthencollectedinthepressure tankfittedwithanexitflowcontrolvalve,whichisusedtocontrol thebackpressureactingonthepump.Abubbleflowmeterisused tomeasuretheoutflow.
2.2. Seriesmultistage
Fig.2showstheschematicoftheseriesmultistagefluidicacous- ticpump.Thisconfigurationconsistedoftwopairsoffluidicdiodes, tworesonatorsandtwodrivers.Thedriverswereelectricallycon- nectedinparallel.Eachdrivercoulddrawpowercomparableto singlestagecasedriver.Theinflowdiodeofthefirstresonator(R1) wasopentotheatmospherewhileitsoutflowdiodewasconnected toahollowtube(nodiode).Thishollowtubereplacedtheinflow diodeofthesecondresonator(R2).Thus,theonlydiodepresent inthesecondresonatorisanoutflowdiode,whichisconnected
tothetank-controlvalve-bubbleflowmeterarrangement.Itwas foundthatwithaninflowdiodeinR2,flowfromR1wasimpeded bytheinflowdiodeinR2,howeverthiswasnotthecasewhenthe inflowdiodewasreplacedbyatube.
2.3. Parallelmultistage
Fig.3 shows theschematicof theparallel multistagefluidic acousticpump.Thisconfigurationwaseffectivelytwosinglestage pumpsconnected togetherat theoutlets.Here also,thedrivers wereelectricallyconnectedinparallel.Theinflowdiodesofboth resonatorswereopentotheatmospherewhiletheoutflowdiodes ofbothresonatorswereconnectedtoawyejunction.Theoutlet ofthewyejunctionisconnectedtothetank-controlvalve-bubble flowmeterarrangement.
2.4. Measurementtechniqueandinstrumentation
Eachresonatorwasdrivenatthefundamentalmodeofvibra- tion.Sinusoidalinputatthefundamentalmodefrequencyfrom afunctiongenerator(TektronixAFG30220B)wasusedtoexcite aloudspeakerhorndriver(Capital 2165/150W).Foreachpump configuration,twodifferentvoltagelevelsviz.,15Vand25Vwere suppliedwiththehelpofadigitalmulti-meter(YokogawaModel 73201).Correspondingpowerinputlevelsweremeasuredusing awattmeter(MECO-G150V-5A).Theresolutionofthewattmeter andvoltmeterwere2Wand0.01V,respectively.
Twokindsofpressuredatawereacquired.Acousticpressure amplitudeatthesmallendoftheconicalresonatorswasmonitored usingapiezoelectricpressuretransducer(PCBModel113B28).The meanpressuresinsidethepressuretank(inallcases)andinsideR2 inthecaseofseriesmultistagingweremeasuredusingasolidstate piezo-resistivesensor(OmegaPX140).
Outflowwasmeasuredusingabubble flowmeter (Teledyne Hastings-Raydist,100mltube),intermsoflitersperminute(LPM), asintheearlierwork[20].Themovementofthebubblewascap- turedusingahigh-speedcamera(PCODIMAX)setataframerate of500Hz.Thevolumetraversedandthecorrespondingtimetaken areusedtocalculatethevolumeflowrate(seeEqn.2).Inorderto obtainflowrateatdifferentbackpressures,acontrolvalvewasused tovarythebackpressure.Forzeroflowratebackpressure,thecon- trolvalvewascompletelyclosedandforzerobackpressureflow rate,thecontrolvalvewascompletelyopen.Theleastbackpressure possibleinthisarrangementwasaround35Pa.Thesebackpressure andflowratereadingswereusedtocharacterizethepump.Flow rateinLPMwascomputedaccordingtoEqn.(2)
QLPM=Volumetraversesdbybubble (ml) Timeelapsed(s) × 60
1000 (2)
3. Resultsanddiscussion
Allexperimentswereconductedwithambientairasthepump- ingfluidatatemperatureof23–250Candhumidityintherangeof 65–70%RH.Thefundamentalmodefrequencyofthenonuniform resonatorwasfoundtobe915Hzforallthepumpconfigurations.
Flowratesweremeasuredfortwodifferentdrivingvoltages;viz., 15Vand25V,atfourbackpressures,forallthepumpconfigura- tions.
Asmentionedintheprevioussections,eachpumpconfigura- tionhasa differentarrangement.Thus,thepowerconsumption ofthepumpwilldependuponitsspecificconfiguration.Table1 summarizesthepowerconsumptionfordifferentconfigurations.
Thesepowerconsumptionvaluesareusedtodeterminetheacous- ticpowerinput.
Fig.1.Schematicoftheexperimentalsetupforasinglestagepumpalongwithzoomedinviewofthefluidicdiodeconfiguration(onlyinternaldimensionsofthediodesare shown).
Fig.2.Seriesmultistagepumparrangement.
Table1
Powerconsumptionfordifferentpumpconfigurations.
PumpConfiguration Voltage(volts) Power(watts)
SingleStage 15 5
25 20
SeriesMultistage 15 16
25 60
ParallelMultistage 15 16
25 60
3.1. Pumpcharacteristicsandefficiency
Theperformanceofallthreepumpconfigurationscanbeunder- stoodintermsoftheircharacteristiccurves.Weassumealinearfit forthebackpressure-flowratedatawithaminimumcoefficient ofdeterminationof0.98.Thisisconsistentwiththefactthatthere arenosuddenchangesineitherflowrateorbackpressureoverthe rangeofoperation.Thelinearcharacteristiccurvecanbedescribed byEqn.(3)
4 S.K.Thomas,A.BandT.M.Muruganandam/SensorsandActuatorsA301(2020)111751
Fig.3.Parallelmultistagepumparrangement.
P=P0−kQ (3)
Where,Pisthemeanbackpressure,Qistheflowrate,P0isthezero flowmeanbackpressureandkistheslopeofthecharacteristic curve.
Thepowerinputthatisbeingmeasuredisthepowerinputto theloudspeakerdriverfromtheamplifier.However,loudspeak- ersareextremelypooratconvertingelectricalenergytoacoustic energy.Therefore,theoverallpumpefficiencyisnotatruemeasure oftheefficiencyofanygivenpumpingarrangement.Toremedythis, pumpefficiencyisdefinedasinEq.(4)
= Flowpoweroutput(Q×P)
Acousticpowerinput (4)
Thetypicalefficiency(electricaltoacousticconversion)ofthe loudspeakerisaround1%,whichisusedtofindtheinputacoustic power.
Theperformancecharacteristicsofallthreeconfigurationsfor bothdrivingvoltagelevelsareplottedsimultaneouslyinFig.4(a) and(b).Table2summarizestheresultsforallpumpconfigurations andalldrivingpowers.Withincreaseinvoltage,theperformance curvesforallthreeconfigurationsappeartobeshiftedupwards toahigherP0withmarginalincreaseinabsoluteslope’k’.Atboth drivingvoltages,seriesconfigurationdelivershigherzeroflowback pressuresthaneithersinglestageorparallelmultistage,whereas, parallelconfigurationattainsmuchhigherflowratesatlowback pressuresthaneithersinglestageorseriesconfiguration.Moreover, theparallelconfigurationachievesmorethandoubletheflowrate, whiletheseriesconfigurationachieveslessthandoubletheback pressures,compared tothesinglestagepump.Singlestageand parallelconfigurationshaveroughlythesameP0foragivendriving amplitude.
Theefficiencycharacteristicsofallthreeconfigurationsat15V and25VdrivingamplitudesareplottedinFig.5(a)and(b),respec- tively.The efficiencyvalues by definitionare zeroat zero flow conditionsandatzerobackpressureconditions.Thesinglestage configurationhashigherpeakefficiencythanbothseriesandpar- allelmultistageconfigurationsirrespectiveofdrivingamplitude.
Thisismostlikelyduetointeractionbetweenthetworesonators, andtheconnectionsbetweentheminmultistagedpumps.
Intheseriesarrangement,thefirstresonator(R1)pumpsairinto thesecondresonator(R2)inordertoraisethemeanpressureinside
it.R2thenpumpsairathigherpressureintothetank.Themean pressureinR2intheseriesconfigurationwasmeasuredforallthe cases.Thisdataalongwiththetankmeanpressureispresentedin Fig.6atdifferentflowratessettings.Itisevidentthatforagiven driving,asthebackpressureincreases,themeanpressureinR2 isalsoincreasing.Atthezeroflowconditions,thepressureinR2 iscomparable tothepressureinthetank. Forallthecases,the pressureat25Vdrivingishigherthanthatfor15Vcases.
Table2alsoliststheacousticpeakpressureamplitude(ppk,R1 andppk,R2)atthesmallendoftheresonators(R1andR2)forall configurations.Increaseinthesmallendamplitudewithincreasein drivingamplitudeisevidentacrossallconfigurations.FromTable2, themoststrikingobservationregardingtheacousticdataisthatthe differencebetweenthesmallendamplitudesismorepronounced inthecaseoftheseriesconfigurationascomparedtoparallelcon- figuration.R1hasanamplitudecomparabletothatofsinglepump resonatorwhilethatofR2isreducedtohalfatbothdrivingvolt- ages.Thiscouldbeduetotheusageofplaintubeinsteadofinflow diodeinthecaseofR2.
Anotherobservationisthattheresonatorsmallendacoustic pressureamplitudedropsbyabout31%whentheresonatorsare connectedtogetherinparallelconfiguration(seeTable2).Onecan alsonotethat,R2pressuresareabout10%higherthanR1pressures.
Thismaybeduetosomeintrinsicdissimilaritiesbetweenthetwo resonatorsanddrivers.
3.2. Commentsonmultistaging 3.2.1. Flowandbackpressure
Intheseriesmultistaging,itisexpectedthatthemeanpressures willbedoubledforagivenflowrate.However,itcanbeseenfrom Table2,thebackpressureatzeroflowrateisroughly1.8timesfor 15Vand1.6timesfor25V.Itwasobservedthatthepowerdrawn togetherbythedriverswasalmostthreetimesthatofthesingle stagepumpdriver(seeTable1).
Inthecaseofaparallelpumparrangement,onewouldexpect thattheflowrateswouldbedoubledatagivenbackpressure.In thiscasealso,itwasobservedthatthepowerdrawntogetherby thedriverswasalmostthreetimesthatofthesinglestagepump driver(seeTable1).Thustheexpectedflowratesmustbemore
Fig.4. Pumpcharacteristics(a)15Vand(b)25V.Errorbarsaresmallerthanthemarkersize.
Table2
Performanceparametersofallpumpconfigurationsat15Vand25V.
PumpConfiguration DrivingVoltage(V) P0(Pa) Qmax(LPM) peak(%) Slope(k)(Pa/LPM) ppk,R1(kPa) ppk,R2(kPa)
Single 15 419 2.24 8.6 168.6 14.2 –
25 961 4.31 9.8 197.6 21 –
Series 15 771 3.43 7.2 213.2 14.2 7.0
25 1546 5.67 6.2 265.9 21 9.6
Parallel 15 449 5.27 7.3 71.9 9.7 10.7
25 901 8.88 6.2 89.8 14.8 16.3
Fig.5.Pumpefficiency(a)15Vand(b)25V.
thantwice.Theactualflowrateriseis2.3timesthesinglestagefor 15V,and2.1timesat25Vdriving(seeTable2).
3.2.2. Acoustics
Oneofthemajorconsiderationsinthemultistageassemblyof thesepumpsistheinteractionbetweensoundwavesexitingthe resonatorsthroughthediodesandtheresonators.Itwasensured
thatboththedrivers,inbothseriesandparallelarrangement,were drivenwithoutanyphaselag.
It can beseen that, in seriesmultistaging, R1 performs just asgood asa singlestagepump,whileR2is havinglesserpeak pressures.Thismaybeduetotheinteractionbetweentheacous- ticwavesandtherectifiedflowenteringR2fromR1.Asseenin Fig.2,seriesarrangementhastheinflowdiodeoftheR2asasim-
6 S.K.Thomas,A.BandT.M.Muruganandam/SensorsandActuatorsA301(2020)111751
Fig.6. R2meanpressureandthetankmeanpressureatdifferentflowratesinthe caseofaseriesmultistagepump.Errorbarsaresmallerthanthemarkersize.
plestraighthollowtubeinsteadofadiode.Whendiodewasused instead,therewasnomeanpressureincreaseinR2.Thismaybe due totheinteractionbetweenthetwo fluidic diodes,but this wasnot investigatedfurther.Carewasalsotakentoavoidsud- denbendsinthepathofthetravellingwaveandtherectifiedflow, sincesuddenbendsinflowpathcorrespondtochangesinthechar- acteristicimpedance,whichcandirectlyhampertheperformance ofthesepumps.Theactuallengthoftheinterconnectingtubemay alsohaveaneffectduetoanyphasemismatchbetweenthetrav- elingwaveandthewaveinR2.Positionofdiodeelementsinthe interconnectingtubesisalsoafactorwhichcouldaffecttheoverall acousticbehavior,butthesedependencieswerenotinvestigatedin thisstudy.
Ontheotherhand,intheparallelarrangement,thepeakpres- suresarecomparableinR1andR2.Itisintriguingthattheindividual peakpressuresintheresonatorsarelowerthanthatofthesin- glestageresonator,even afterdriversdrawingroughly 3times thepower.Theoutputtubelengthswereensuredtobethesame forboththelegsofthewye.Thus,theremustbeaneffectofthe interactionbetweenthetwoflows/acousticwavesinthewye.
Thisalsodemonstratesthat,becauseofacoustics,multistaging ofacousticpumpsneedsmoreattentionthanmultistagingofcon- ventionalpumps.However,itappearsthatparallelarrangement haslesserinteractioneffectscomparedtoseriesarrangement.
4. Conclusion
Multistagefluidicacousticpumps,basedonnonuniformarea resonator,hasbeentestedinbothparallelandseriesconfigura- tions.Theresultsofmultistagepumpswerecomparedwithsingle stagepump.Higherbackpressuresofupto1.8timesthatofsingle stagepumphasbeenattainedusingseriesmultistagepump.Higher flowratesofupto2.3timesthatofsinglestagepumphasbeen achievedbyparallelstaging.Seriesstagepumpyieldedmaximum backpressureof1546Paat25V.Maximumflowrateof8.88LPM wasobtainedwithparallelstagepumpdrivenat25V.Maximum efficiencyof9.8%wasrecordedforsinglestagepumpoperating at25V.Themultistagepumpshadefficiencieslowerthanthatof singlestagepump.Bothseriesandparallelpumpsconsumedthree timestheelectricalpowercomparedtothesinglestagepump.
Fromtheacousticperformanceviewpoint,whenoperatingin series,thefirststageresonator(R1)wasfoundtooperateiden- ticaltothesinglestagepump,whilethesecondstageresonator (R2)washavinghighermeanpressuresandloweracousticpeak pressures.Ontheotherhand,whenoperatinginparallel,thepeak pressuresinbothresonatorswerelowercomparedtothesingle stagepump.Preliminaryinferenceisthatparallelmultistaginghas lesserperformancedegradationcomparedtoseriesmultistaging.
Thispaperonlypresentedthefeasibilitystudyformultistag- ingoffluidicacousticpumpsforachievinghigherflowratesand pressures.Theexactoptimumconfigurationforbestoperationof
thesemultistagedpumpsneedstobearrivedat.However,itisclear fromthestudythattheinteractionofacousticsineachoftheres- onators,diodes,connectingelementsandtank,makesthebehavior ofmultistagedacousticpumpsdifferentfromthatofconventional multistagedpumps.
ConflictofInterest
Allauthorshaveparticipatedin(a)conceptionanddesign,or analysis and interpretationof thedata; (b) draftingthe article orrevisingitcriticallyforimportantintellectualcontent;and(c) approvalofthefinalversion.
Thismanuscripthasnotbeensubmittedto,norisunderreview at,anotherjournalorotherpublishingvenue.
Theauthorshavenoaffiliation withanyorganizationwitha directorindirectfinancialinterestinthesubjectmatterdiscussed inthemanuscript
References
[1]N.-T.Nguyen,X.Huang,T.K.Chuan,MEMS-micropumps:areview,J.Fluids Eng.124(2002)384–392,http://dx.doi.org/10.1115/1.1459075.
[2]R.Tippetts,AFluidicPumpforuseinNuclearFuelReprocessing,in:Proc.5th Int.FluidPowerSymp.,Bedford,1978.
[3]V.Tesaˇr,Safepumpingofhazardousliquids-Asurveyofno-moving-part pumpprinciples,Chem.Eng.J.168(2011)23–34,http://dx.doi.org/10.1016/j.
cej.2011.01.046.
[4]E.Stemme,G.Stemme,Avalvelessdiffuser/nozzle-basedfluidpump,Sensors ActuatorsAPhys.39(1993)159–167,http://dx.doi.org/10.1016/0924- 4247(93)80213-Z.
[5]T.Gerlach,M.Schuenemann,H.Wurmus,Anewmicropumpprincipleofthe reciprocatingtypeusingpyramidicmicroflowchannelsaspassivevalves,J.
Micromech.Microeng.5(1995)199–201,http://dx.doi.org/10.1088/0960- 1317/5/2/039.
[6]A.Olsson,G.Stemme,E.Stemme,Avalvelessplanarfluidpumpwithtwo pumpchambers,SensorsActuatorsAPhys.46–47(1995)549–556.
[7]A.Olsson,G.Stemme,E.Stemme,TheFirstValve-lessDiffuserGasPump, Proc.IEEETenthAnnu.Int.Work.MicroelectroMech.Syst.AnInvestig.Micro struct.Sensors,Actuators,Mach.Robot.,1997,http://dx.doi.org/10.1109/
MEMSYS.1997.581780.
[8]A.Olsson,G.Stemme,E.Stemme,Numericalandexperimentalstudiesof flat-walleddiffuserelementsforvalve-lessmicropumps,SensorsActuatorsA Phys.84(2000)165–175,http://dx.doi.org/10.1016/S0924-4247(99)00320-9.
[9]V.Tesaˇr,Valve-lessrectificationpumps,Encycl.Microfluid.Nanofluidics.
(2015)3399–3415,http://dx.doi.org/10.1007/978-1-4614-5491-51656.
[10]D.Rinderknecht,A.I.Hickerson,M.Gharib,Avalvelessmicroimpedance pumpdrivenbyelectromagneticactuation,J.Micromech.Microeng.15 (2005)861–866,http://dx.doi.org/10.1088/0960-1317/15/4/026.
[11]M.Nabavi,K.Siddiqui,J.Dargahi,Analysisoftheflowstructureinsidethe valvelessstandingwavepump,Phys.Fluids(1994)20(2008)1–10,http://dx.
doi.org/10.1063/1.3026074.
[12]M.Nabavi,L.Mongeau,Numericalanalysisofhighfrequencypulsatingflows throughadiffuser-nozzleelementinvalvelessacousticmicropumps, Microfluid.Nanofluidics7(2009)669–681,http://dx.doi.org/10.1007/s10404- 009-0427-4.
[13]G.Stemme,E.Stemme,Avalvelessdiffusernozzlebasedfluidpump,Sens.
ActuatorsAPhys.2(1993)156–167.
[14]S.K.Thomas,T.M.Muruganandam,Areviewofacousticcompressorsand pumpsfromfluidicsperspective,SensorsActuatorsAPhys.283(2018)42–53, http://dx.doi.org/10.1016/j.sna.2018.09.031.
[15]M.A.Ilgamov,R.G.Zaripov,R.G.Galiullin,V.B.Repin,Nonlinearoscillationsof agasinatube,Appl.Mech.Rev.49(1996)137–154,http://dx.doi.org/10.
1115/1.3101922.
[16]R.A.Saenger,G.E.Hudson,Periodicshockwavesinresonatinggascolumns,J.
Acoust.Soc.Am.32(1960)961–970,http://dx.doi.org/10.1121/1.1908343.
[17]T.S.Lucas,T.W.VanDoren,ResonantMacrosonicSynthesis,USPatent US5515684,1996.
[18]C.C.Lawrenson,B.Lipkens,T.S.Lucas,D.K.Perkins,T.W.VanDoren, Measurementsofmacrosonicstandingwavesinoscillatingclosedcavities,J.
Acoust.Soc.Am.104(1998)623–636.
[19]S.K.Thomas,T.M.Muruganandam,Nonuniformresonatorbasedvalve-less standingwavesuctionpumpforgases,SensorsActuatorsAPhys.261(2017) 40–48,http://dx.doi.org/10.1016/j.sna.2017.05.004.
[20]S.K.Thomas,T.M.Muruganandam,Acousticblowerusingfluidicdiodesanda nonuniformresonator,Int.J.FlowControl.7(2015)55–66,http://dx.doi.org/
10.1260/1756-8250.7.1-2.55.
[21]A.El-Sabbagh,Gas-FilledAxisymmetricAcousticResonators,Universityof Maryland,2005.
[22]M.Kawahashi,M.A.Hossain,T.Fujioka,AcousticCompressorWithTwo Resonators,US7443060B2,2008.
[23]K.A.Dooley,StandingWaveExcitationCavityFluidPump,US6672847B2, 2004.
Biographies
SonuKThomas,Ph.Dreceivedhisbachelor’sdegreeinAeronauticalEngineer- ingfromTheAeronauticalSocietyofIndiain2008.Recently,hereceivedhisMS andPhDinAerospaceEngineeringfromIndianInstituteofTechnology,Madrasin 2016.Currently,heisworkingasapostdoctoralresearcherinMechanicalEngi- neeringDepartment,IndianInstituteofTechnology,Madras.Hisresearchinterests includeductacoustics,gasdynamicsandfluidics.Inparticular-ductacousticsand itsapplicationsinfluidics.
AkashB.,receivedhisbachelor’sdegreeinMechanicalEngineeringfromUniversity ofKeralain2017.Recently,hereceivedhisMTechinAerospaceEngineeringfrom IndianInstituteofTechnologyMadrasin2019.Hisresearchinterestsincludegas dynamics,ductacousticsandnumericalsimulationofflows.
T.M.Muruganandam,Ph.DiscurrentlyaProfessorofAerospaceEngineeringin theIndianInstituteofTechnology,Madras.HereceivedhisPhDfromGeorgiaTech, Atlanta,USA,in2006andjoinedthefacultyofIndianInstituteofTechnologyMadras AerospaceDepartmentsoonafter.HehaswontheYoungFacultyRecognition AwardfromIndianInstituteofTechnologyMadrasin2015.Hisresearchinter- estsincludeadvanceddiagnosticsincombustion,ductacoustics,fluidicsandhigh speedflows.
