Numerical Simulation on the Cavity-Induced Boundary Layer Transition

The boundary layer transition can be triggered in either natural or forced way. In this paper, a Mach 3 cavity-induced boundary layer transition is simulated using the implicit large eddy simulation, in order to study the transition caused by the surface gap on the vehicles in the real condition. One of the characteristics of this paper is that no disturbance is imposed in the inflow condition such that the boundary layer transition is triggered by the self-sustained fluctuation in the upstream cavity. Results show that the transition appears in the natural scenario and the stage of the linear instability seems to be followed by the process of the secondary instability. Linear stability analyses are also utilized to show the development of the unstable modes.