MODELING OF RAPID PRESSURE-STRAIN IN REYNOLDS STRESS CLOSURES - DIFFICULTIES ASSOCIATED WITH ROTATIONAL MEAN FLOWS

Intercomponent energy transfer within the context of Reynolds stress c losures is studied. Attention is focussed on the rapid limit of homoge neous flow situations where this energy transfer is caused solely by t he rapid pressure strain rate. We present and analyze the performance of the recently proposed rapid pressure strain rate model of Johansson & Hallback (J Fluid Mech. 1994) in various homogeneous (rapid) flow s ituations, and compare with results obtained with other models from th e literature and rapid distortion solutions. The prediction difficulti es associated with rotational mean flows are analyzed. A generally for mulated test case, which as special cases comprises, e.g. plane strain and homogeneous shear flow, is used to illustrate the modelling diffi culties associated with rotational mean flows. An axisymmetric case is used to demonstrate that parts of the spectrum with anti-reflectional symmetry, which are instrumental for the dynamics when rotational eff ects are present, are totally missed in classical Reynolds stress clos ures. A closer prediction in cases with strong influence of rotation w ould require introduction of other transported quantities.