Effect of Streamwise Wall Curvature on Compressible Turbulent Boundary Layers

The mechanism of the turbulent motion is influenced by the density stratification, which is stable under the action of centrifugal acceleration in a boundary layer over a convex wall. On a concave wall the density stratification is unstable near the surface and stable farther away from it. The contribution of centrifugal and Coriolis forces to the turbulent energy production is discussed. The turbulent heat exchange is regarded as a transport of entropy fluctuations. Simple relations are proposed for shear stress and heat flux, which are applied to the flow in the vicinity of curved walls. The velocity profiles are more hollow on convex than on plane surfaces, and fuller shapes appear on concave surfaces.