简介：介绍了一种基于Spalding公式拟合的脊状表面减阻测试方法，相比于用天平等测力设备测试的方法，其优点在于简便实用，从应用实例来看，准确性也是令人满意的．由于该方法依靠的数据基础是壁面边界层内层速度分布，因此，速度分布测量的准确程度是影响该方法测试结果准确与否的决定因素．

简介：Itisaverydifficulttasktodevelopamethodofreducingturbulentboundarylayerdrag.However,inrecentyears,plasmaflowcontroltechnologyhasdemonstratedhugepotentialinfrictiondragreduction.Tofurtherinvestigatethisissue,asmoothplatemodelwasdesignedasatestingobjectarrangedwithabidirectionaldielectric-barrier-discharge(DBD)plasmaactuator.Inaddition,measurementofskinfrictiondragwasachievedbyapplyinghotwireanemometrytoobtainthevelocitydistributionoftheturbulentboundarylayer.AmethodofquantifyingthefrictiondrageffectwasadoptedbasedontheSpaldingformulafittedwiththeexperimentdata.Whenplasmaactuationwasconducted,avelocitydefectoccurredatthetwomeasuringpositions,comparedwiththenoplasmacontrolcondition;thismeansthattheDBDplasmaactuationcouldreducethedragsuccessfullyinthedownstreamoftheactuator.Moreover,dragreductioncausedbybackwardactuationwasslightlymoreefficientthanthatcausedbyforwardactuation.Withanincreasingdistancefromplasmaactuation,thedrag-reductioneffectcouldbecomeweaker.Experimentalresultsalsoshowthattheimprovementofdrag-reductionefficiencyusingaDBDplasmaactuatorcanachieveabout8.78%inthelocalregionoftheexperimentalflatmodel.