EFFECT OF CURVATURE ON STATIONARY CROSS-FLOW INSTABILITY OF A 3-DIMENSIONAL BOUNDARY-LAYER

An incompressible three-dimensional laminar boundary-layer flow over a swept wing is used as a model to study both the wall-curvature and st reamline-curvature effects on the stationary crossflow instability. Th e basic state is obtained by solving the full Navier-Stokes (N-S) equa tions numerically. The linear disturbance equations are cast on a fixe d, body-intrinsic, curvilinear coordinate system. Those nonparallel te rms which contribute mainly to the streamline-curvature effect are ret ained in the formulation of the disturbance equations and approximated by their local finite difference values. The resulting eigenvalue pro blem is solved by a Chebyshev collocation method. The present results indicate that the convex wall curvature has a stabilizing effect, wher eas the streamline curvature has a destabilizing effect. A validation of these effects with an N-S solution for the linear disturbance flow is provided.