Streamwise Curvature Effect on the Incompressible Turbulent Mean Velocity Over Curved Surfaces

Abstract

A curvature law of the wall, which determines the mean velocity profile, is analytically derived for near-wall turbulent flows to include strong curved-channel wall curvature effects through a perturbation analysis. The new law allows improved analysis of such flows, and it provides the basis for improved wall function boundary conditions for their computation (CFD), even for strong curvature cases. The improved law is based on the algebraic eddy viscosity and curvature-corrected mixing length concepts, the latter of which is a linear function of the gradient Richardson number. To include the complete Richardson number effects, the local streamline curvature effects in the gradient Richardson number are kept. To overcome the mathematical difficulty of keeping all of these local streamline curvature terms, an innovative nonconstant-parameter perturbation solution technique is successfully applied. [S0098-2202(00)00903-2]