Natural transition of the supersonic streamwise corner flow

The laminar-to-turbulence transition of a streamwise corner flow is recognized to occur first at the corner based on the stability analysis, but there is no persuasive experimental evidence to back it up, especially for supersonic flow. In this work, natural transition in a supersonic corner boundary layer has been experimentally studied using a nanoparticle-based planar laser scattering technique. It is inspiring to observe that the natural transition position of the corner boundary layer shows a random behavior among the corner side, flat-plate side, and their combination. Based on an intermittent factor analysis, these stochastic transitions show a dominant preference for transitions occurring near the corner region.