ADVANCED TURBULENCE CLOSURE MODELS - A VIEW OF CURRENT STATUS AND FUTURE-PROSPECTS

This report presents the status and reviews some of the current activities in the development of advanced one-point turbulence closure models with special reference to the modeling and computation of turbulent wall flows. It gives a brief retrospective of the development of the one-point closure models and highlights major achievements. It also recalls some of the pertinent issues that are still open and that pose challenges to modelers. Some pertaining deficiencies, which have been obvious since the very beginning of the development and are still present, are discussed, together with some marked differences in the views of various groups of modelers. The review is limited to conventional one-point two-equation Eddy Viscosity Models (EVMs) and Differential Second-Moment (Re-stress) Models (DSMs). It does not deal with any spectral approach, nor partial field models, such as subgrid modeling or similar methods used within the framework of other simulation techniques. Some new approaches, such as the Renormalization group theory (RNG), are mentioned briefly and only insofar as they may inspire modifications and improvements of conventional models. The report deals with general aspects of modeling complex turbulent flows, but is restricted to incompressible (or mildly compressible) fluid, with particular focus on computation of wall flows.