Diffraction of a weak shock with vortex generation

Abstract

The region of finite vorticity near the edge of a diffracting wedge is investigated. Dimensional analysis gives the dependence of the circulation and the velocity of the vortex region on the pulse strength. A close estimate of the magnitude of the magnitude of these quantities is obtained by replacing the vortex region by a single concentrated vortex. The theoretical conditions at the sharp edge are discussed and compared with observations of real fluid behaviour. A short account of the theory of the core of the spiral vortex sheet in a perfect fluid is appended.The research reported herein was supported by the United States Air Force, through the Office of Scientific Research of the Air Research and Development Command.