Predicting Hypersonic Boundary-Layer Transition on Complex Geometries

Abstract

Laminar-turbulent transition strongly affects drag, aerothermal heat load, and the effectiveness of aerodynamic control surfaces for hypersonic vehicles. Reliable transition prediction and control is therefore a key technology for improved design of reusable launch and re-entry vehicles, missile interceptors and missiles for time-critical strike. AVT-346 organized cooperative hypersonic-transition research to improve our understanding of the following phenomena: 1) mechanisms of boundary-layer transition as affected by separation bubbles near control surfaces or compression corners; 2) mechanisms of transition on complex surfaces with multiple interacting instabilities; 3) ability to predict the effect of high enthalpy on transition induced by the second-mode instability; and 4) ability to predict the effect of ablation. Improvements in physical understanding resulted, along with improved experimental and numerical simulation capabilities.