Structure-based turbulence modeling for wall-bounded flows

The performance of Reynolds stress transport (RST) models in non-equilibriu m flows is limited by the lack of information about two dynamically importa nt effects: the role of energy-containing turbulence structure (dimensional ity) and the breaking of reflectional symmetry due to strong mean or frame rotation. Both effects are fundamentally non-local in nature and this expla ins why it has been difficult to include them in one-point closures like RS T models. Information about the energy-containing structure is necessary if turbulence models are to reflect differences in dynamic behavior associate d with structures of different dimensionality (nearly isotropic turbulence vs turbulence with strongly organized two-dimensional structures). Informat ion about the breaking of reflectional symmetry is important whenever mean rotation is dynamically important (flow through axisymmetric diffuser or no zzle with swirl, flow through turbomachinery, etc.). Here we present a new one-point model that incorporates the needed structure information, and sho w a selection of results for homogeneous and inhomogeneous flows. (C) 2000 Begell House Inc. Published by Elsevier Science Inc. All rights reserved.