40 Years of Transition Research at NASA: A Personal Perspective

An overview of the laminar-turbulent transition research conducted by the author and his colleagues at NASA during the past few decades is presented in this paper. This includes development of computational methods for compressible stability analysis, linear and nonlinear parabolized stability equations, development of quiet supersonic and hypersonic tunnels, supersonic and hypersonic boundary layer transition prediction including the effects of nose bluntness and gas chemistry, resolution of cone-to-flat plate transition controversy, instability and transition in rotating disk flow, secondary instability of Gortler and crossflow disturbances and instability of the attachment-line boundary layer. As a result of the computational and experimental research conducted at NASA, the understanding of transition mechanisms was greatly enhanced and prediction tools developed for across the speed regime. The research also provided the necessary foundation for additional developments by the transition community to solve this challenging problem in fluid dynamics.