Prediction of the effect of streamline curvature on turbulence

Abstract

It is shown that the observed effects of small amounts of streamline curvature on turbulence are accounted for by the curvature terms which appear in the Reynolds stress equations and in the turbulence model of Launder, Reece, and Rodi. Because of the smallness of these terms, this is a surprising result, but their effect is shown to appear in a magnified form in the effective eddy viscosity. A comparison is made between computed solutions of the modeled Reynolds stress, mean momentum and dissipation rate equations, and experimental data for curved wall jets, a curved free jet, and curved boundary layers. The curvature effects are well predicted when the curvature terms are included. The turbulence model implies that the turbulence shear stress is relatively insensitive to longitudinal accelaration which seems to be in reasonable agreement with experiment.