Design optimization of hypersonic vehicles for boundary-layer stability

In this work, we present a methodology for a shape-based hypersonic vehicle optimization driven by boundary-layer stability properties. Full Navier-Stokes CFD calculations are performed at each parametric design point for both axisymmetric and three-dimensional surface geometries. Boundary-layer stability analysis is then performed through application of the parabolized stability equations. The performance metric used for the optimization procedure is either the N factor, representing the integrated growth rate of naturallyoccurring disturbances in the boundary-layer, or a predicted boundary-layer transition location based on a correlation of the N factor with experimental results. Optimization then involves minimization or maximization of this value.