USAT: Unified Software for Analysis of Transition

"Laminar-Turbulent transition phenomenon in hypersonic flows remains poorly understood although it has a profound impact on the thermal protection system weight, vehicle drag and air-breathing engine performance. Transition location uncertainties forcedesigners to be conservative by adding weight and reducing thrust. Efficient techniques for prediction and control of boundary-layer transition are needed. The proposed effort deals with the development of a unified software package for advancedtransition analysis and prediction. This transition prediction tool includes the effect of external (free-stream, wall-induced) disturbances on boundary-layer transition which is accomplished by coupling a receptivity module with a disturbance growthmodule. The receptivity module determines the relationship between the imposed disturbances and boundary-layer instability waves, while the disturbance growth module computes the evolution of these instabilities and determines the location of transition.The disturbance growth and the receptivity modules will be incorporated in the unified software package, USAT, in a way that minimizes problem setup time as well as computational time. The software package will be developed for use by aerospace designers."