Vortexlet formation in Schardin's problem

The present study focuses on the shock diffraction problem over a triangle wedge for Mach numbers of M = 1.3, 1.5, 1.7, and 2.0 by using a two-dimensional, high-order, in-house Euler solver. The solver is based on a family of advection upstream splitting method in combination with a central essentially non-oscillatory scheme and benefits a block-based adaptive mesh refinement algorithm to resolve the regions that contain discontinuities. High accuracies in time and space, and adaptive mesh refinement capabilities of the solver allow us to investigate vortexlet formation mechanism in detail. Our results reveal that there are two different types of vortexlet formation mechanisms. While the first type of formation is observed at all Mach numbers considered here, the second type arises when the Mach number is greater than 1.3. This difference results from their driving mechanisms, which are the upward moving accelerated shock and embedded shock in the primary vortex. In addition to their driving mechanisms, two types are also different in terms of their locations.