简介:Duty-cyclemodulationalternatelyblowingfromtwoopposite-facingplasmaactuatorsontheleewardsurfaceneartheapexofaconewitha10semi-apexangleisadoptedtocontrolmeanlateralforceandmoment,andtheflowcontrolmechanismsarepresented.Pressuredistributionsovertheforebodyoftheconearemeasuredbysteadypressuretappings.Theexperimentsareperformedina3.0×1.6mopen-circuitwindtunnelatawindspeedof20m/s,a45angleofattackandaReynoldsnumberof2×105,basedonthediameterofthebaseofthecone.Almostlinearlyproportionalcontrolofthelateralforcesandmomentsoveraslenderconicalforebodyatahighangleofattackhasbeendemonstratedbyemployingapairofsingledielectricbarrierdischargeplasmaactuatorsneartheapexofthecone,combinedwithaduty-cycletechnique.Thepressuredistributionmeasurementsindicatethatthebi-stablevortexpatternappearstobeshiftedintheoppositedirectionwhentheportorstarboardactuatorisactivated,whiletheotheriskeptoffduringthetest.Itisshownthatthereducedpulse-repetitionfrequencybasedonthelocaldiameterattheplasmaactuatorequaltooneyieldsthehighesteffectivenessamongthecasesconsidered.
简介:Tomakethelarge-scaleheliumcryogenicsystemoffusiondeviceEAST(experimentaladvancedsuper-conductingtokamak)runstably,asthecorepart,theheliumturbineexpandermustmeettherequirementofrefrigerationcapacity.However,previousdesignswerebasedononedimensionflowtodeterminetheaveragefluidparametersandgeometricparametersofimpellercross-sections,sothatitcouldnotdescriberealphysicalprocessesintheinternalflowoftheturbineexpander.Therefore,basedontheinversepropositionofstreamlinecurvaturemethodinthecontextofquasi-three-dimensionalflows,theall-over-controlledvortexconceptwasadoptedtodesigntheimpellerunderspecifiedcondition.Thewrapangleoftheimpellerbladeandthewholeflowdistributiononthemeridianplanewereobtained;meanwhiletheperformanceofthedesignedimpellerwasanalyzed.Thusanewdesignmethodisproposedherefortheinversepropositionoftheheliumturbineexpanderimpeller.