alpha-, beta-phenomena for the supersonic flow around an impulsively started circular cylinder

The vortex dynamics of a supersonic flow past an impulsively started circular cylinder are studied numerically. A well-developed high-order finite difference method is adopted to solve the two-dimensional Navier-Stokes equations. In particular, Ma = 1.1 and Re = 2.2 x 10(4) are selected to report the vortex evolution process. The results confirm that the alpha-, beta-, sub-alpha-, and sub-beta-phenomena observed in incompressible flow in the separated region do exist in the supersonic regime. In addition, the influence of Mach number and Reynolds number on the vortex is also studied, and the vortex changes are compared at Ma = 1.1, 1.7 and Re = 1 x 10(4), 2 x 10(4), 2.5 x 10(4), 3 x 10(4), 5 x 10(4), and 1 x 10(5). (c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).