简介：摘要波音机队普遍使用的备用无线电导航指示器RDMI-734型无线电磁距指示器，存在非计划拆换率高、修理后装机时间短等问题。本文通过对该部件结构及工作原理的分析，结合波音和生产商Collins提供的相关资料和航空公司的修理数据，寻找出造成此类问题的原因并提供解决方案。

简介：Inthispaper,aerodynamicactuationcharacteristicsofradio-frequency(RF)dischargeplasmaarestudiedandamethodisproposedforshockwavecontrolbasedonRFdischarge.Underthestaticcondition,aRFdiffuseglowdischargecanbeobserved;underthesupersonicinflow,theplasmaisblowndownstreambutremainscontinuousandstable.Time-resolvedschlierenisusedforflowfieldvisualization.ItisfoundthatRFdischargenotonlyleadstocontinuousenergydepositionontheelectrodesurfacebutalsoinducesacompressionwave.Underthesupersonicinflowcondition,aweakobliqueshockwaveisinducedbydischarge.Experimentalresultsoftheshockwavecontrolindicatethattheappliedactuationcandispersethebottomstructureoftheramp-inducedobliqueshockwave,whichisalsoobservedintheextractedshockwavestructureafterimageprocessing.Moreimportantly,thiscontroleffectcanbemaintainedsteadilyduetothecontinuoushigh-frequency(MHz)discharge.Finally,correlationsforschlierenimagesandnumericalsimulationsareemployedtofurtherexploretheflowcontrolmechanism.Itisobservedthatthevortexintheboundarylayerincreasesaftertheapplicationofactuation,meaningthattheboundarylayerinthedownstreamoftheactuationpositionisthickened.Thisisequivalenttocoveringalayeroflow-densitysmoothwallaroundthecompressioncornerandontherampsurface,therebyweakeningthecompressibilityatthecompressioncorner.OurresultsdemonstratetheabilityofRFplasmaaerodynamicactuationtocontrolthesupersonicairflow.