On the stability of turbulent wall jets along concave surfaces.

Abstract

Stability analysis for the occurrence of Taylor-Gortler vortices in turbulent wall jets along concave surfaces is studied by comparative experiment. The eddy viscosity expression in the perturbation equations are determined from a modified version of a two-equation turbulence model including curvature, which predictes well the main features of the turbulent wall jets along concave surfaces. From the stability analysis, it is found that the minimum curvature at the neutral stability state decreases slightly as the Reynolds number increases. Then, the theoretical minimum curvature reaches good agreement with the experiment, when the eddy viscosity expression is treated as a function of curvature.