Turbulent Boundary Layer Distorted by a Longitudinal Vortex Pair Produced by a Delta-Wing with an Attack Angle (Reynolds Stress Profiles in a Symmetrical Plane)

Abstract

An experimental investigation has been made on the Reynolds stress field in the interaction process between boundary layer and longitudinal vortex. Two types longitudinal vortex pair, namely common-flow up and common-flow down, were introduced into developed turbulent boundary layer from the free stream. Effect of the extra rate of strain, ∂W/∂z and ∂V/∂y, was examined in the profiles of three turbulent intensity components and Reynolds shear stress profiles. The boundary layer along symmetrical plane is classified into “cross flow” in case of cfd and “identifiable streamwise vortices” in case of cfu. The extra rates of strain modify magnitude of turbulent intensity and Reynolds shear stress in the inner layer in case of cfd. Otherwise, close to the wall in the case of cfu, local adverse pressure gradient is deduced from the fact that magnitude of transverse divergence is grater than that of spanwise convergence.