Fully three-dimensional transition prediction on swept wings in transonic flows

A stability analyzer for transition prediction over arbitrary three-dimensional wings operating in the transonic regime is proposed, This analyzer is used to illustrate the importance of including the effects of spanwise pressure gradient in transition predictions over such configurations. To this end, three calculation methods were employed: 1) a three-dimensional Euler solver, 2) a three-dimensional boundary-layer solver, and 3) a numerical method for the solution of the linear stability equations based on the temporal formulation, The influence of spanwise pressure gradients is illustrated by the application of this stability analyzer to the flow about the NASA AMES and ONERA-M6 wings. The pertinence of using a fully three-dimensional method rather than the simpler conical-now calculations is demonstrated. The differences between the fully three-dimensional and conical-flow results are of the same order as the curvature or nonparallel effects.