Development of a nonlinear eddy-viscosity closure for the triple-decomposition stability analysis of a turbulent channel
V Kitsios, L Cordier, J-P Bonnet, A Ooi, J Soria
JOURNAL OF FLUID MECHANICS | CAMBRIDGE UNIV PRESS | Published : 2010
The analysis of the instabilities in an unsteady turbulent flow is undertaken using a triple decomposition to distinguish between the time-averaged field, a coherent wave and the remaining turbulent scales of motion. The stability properties of the coherent scale are of interest. Previous studies have relied on prescribed constants to close the equations governing the evolution of the coherent wave. Here we propose an approach where the model constants are determined only from the statistical measures of the unperturbed velocity field. Specifically, a nonlinear eddy-viscosity model is used to close the equations, and is a generalisation of earlier linear eddy-viscosity closures. Unlike previ..View full abstract
The first author would like to thank the Egide group for funding his research stay in France via the Eiffel Doctorate grant. He would also like to thank Thomas Gatski and Bernd Noack for their many discussions on the triple decomposition.