Numerical study of the circular cylinder in supersonic ground effect conditions

A numerical study of the aerodynamics of a circular cylinder section in proximity to the ground surface was performed, for Mach numbers of 1.5 and 2.9 and ground clearances between 2 and 0.125, non-dimensional with respect to the cylinder diameter. The supersonic flow was computed using a finite-volume Reynolds-averaged Navier-Stokes solver, using adequately stabilized numerical schemes. The flow field computed in ground effect conditions was complex, and significantly varied as a function of both variables. The shape and standoff distance of the detached bow shock were very sensitive to changes in ground clearance. The velocity profile in the gap between the cylinder and ground showed significant interactions between the two boundary layers, and a gradually reduced supersonic expansion close the body surface.