Outflow Boundary Condition Issues in Direct Numerical Simulation of Three-Dimensional Plane Wake Flow

Dif!etr;nt choices of ontflow bounda7'1j conditions an, discussed in this paper' anda ptojh;t' choice is used in a hybrirl numerical simulation irluc]: produces datato inucsiiqaie the effect of ouijlou) !)(j'1lndm'y corulition. the connective outjlou.bonnrlar1j condition with the uiau« sprerl as predicted [rom lituxu: stabilit:11 theory'is used. the non refll'c'fi/wli c88 of this type is uiuestiqated and the rcjleciion or'the lac]: of rcjlection in a ill/lf rirfieit plane wake jiou. stuiulat.un: is stiulied.tlu: results of simulation reported in iliis jhlper itulicaie that the wave speedpredicted from linear stability analysis is appropriatc for the conncctiue velocityat the ouijiou. boundm'y of the larq« dr/int plane wake flow. on tlu: litherhand the usc of the [rcestreartr vclocilq for the conoeciiuc speed at the outflowboundary of a larqe dcjicii plane 'inr/,:(' flow also yenemlcs a serious [cedbacl:prohlcu).