Roughness-induced generation of crossflow vortices in three-dimensional boundary layers
Using the parallel-flow assumption and a nonasymptotic adaption of the asymptotic receptivity theory of Goldstein and Ruban, the roughness- induced generation of stationary crossflow vortices as well as nonstationary instability waves in swept-wing, incompressible boundary layers are investigated. Different types of roughness geometries such as a single isolated roughness element or roughness arrays that are periodic in one or both surface directions are treated. Numerical results are presented in the form of a parameter study for the Falkner-Skan-Cooke family of three-dimensional swept-wing boundary layers. In agreement with experimental findings, the parameter study supports earlier conjectures that the receptivity to roughness-induced stationary vortices is likely to be more important than the nonstationary receptivity in the presence of acoustic free stream disturbances unless the latter are extremely high. The effects of curvature and nonparallelity could alter these findings.
scientific article; zbMATH DE number 527631
scientific article