简介:Anumericalsimulationisperformedtofindoutakeyvorticalstructureinthelaminar-turbulenttransition.Alow-speedstreakisgeneratedinsidealaminarboundarylayerusinganisolatedcuboidroughness,aimedatprovidinganenvironmentunstabletoouterdisturbances.Then,ashortdurationjetisissuedintotheboundarylayer.Whenthejetvelocityislow,somevorticesappearintheboundarylayer,butthetransitionoftheboundarylayerdoesnottakeplace.However,whenthejetvelocityexceedsacertainthreshold,twovorticesnewlyappearabovetheelongatedlegsofaV-shapedvortexandonlyoneofthemisstretchedandsurvives.Afterthat,vorticesaregeneratedoneafteranotheraroundthesurvivedone.Bycomparingthedecayedandthesurvivedvortices,itisfoundthatthedifferenceintheirheightsisthekeycharacteristicwhichleadstothetransition.
简介:摘要:在各大企业不断变革研究大背景下,思想政治工作的作用也逐渐变得更加突出,尤其是国有企业。在国企中,政工工作是重点之一 ,寻找并培养政工工作的人才精英是国企的核心任务之一,建设强有力的政工队伍也正是发挥思想政治工作在国企中重要作用的手段之一