Hypersonic Boundary-Layer Transition

Abstract

Boundary-layer transition is a problem that has plagued several generations of aerodynamicists. There are very few things about transition that are known with certainty, other than the fact that it happens if the Reynolds number is large enough. Researchers have been frustrated by the many unsolved transition phenomena, by the fact that transition sometimes by-passes the known linear processes, and by the difficulties of sorting out the many interrelated and complicated effects for investigation. Transition predictors are confronted with many transition prediction methods, all with serious limitations, and insufficient information as to the best method to accomplish their task. Transition history has many examples of conflicting ideas and interpretations, and sudden changes in perspective are not uncommon. Research studies have emphasized the great complexity of the transition process and how little is known about the problem. A good prediction of transition is sometimes perceived as an impossible task.