Curvature Law of the Wall for Swirling Axial Flows

A new law of the wall accounting for curvature effects for swirling axial flows was derived. The curvature influence on turbulent mixing lengths in both axial and tangential directions was examined theoretically using Reynolds Stress Model. For equilibrium flows and weak curvature, identical mixing lengths were derived for both directions. In addition, the effect of shear stress ratio on the near-wall velocities was explored systematically. It was found that the curvature effect in swirling axial flows was suppressed by a factor of 1/(1+σ_w²) compared to that in curved channel flows. Considerably improved agreement with measurements was obtained for the new curvature law compared to the classical logarithmic law.