SHEAR-FREE TURBULENT BOUNDARY-LAYERS .2. NEW CONCEPTS FOR REYNOLDS STRESS TRANSPORT-EQUATION MODELING OF INHOMOGENEOUS FLOWS

Models for the dissipation tenser and (slow) pressure-strain terms of the Reynolds stress transport equations are presented which are applic able near boundaries. These models take into account the large inhomog eneity and anisotropy that can be present near walls and surfaces, and are inspired by the physical insights developed in Part 1 of this pap er. The dissipation tenser model represents a fundamentally new approa ch to dealing with turbulence inhomogeneities. The pressure-strain mod el shows how the classic return-to-isotropy model of Lumley (1978) can be adapted to the near-wall region. The closure hypotheses underlying these two models are tested in an a priori fashion using direct numer ical simulation (DNS) data.