Diffraction of a two-shock configuration by a concave cylindrical surface

Diffraction of a two-shock configuration by a concave cylindrical surface with a continuously varying angle of diffraction in a perfect (inviscid and non-heat-conducting) gas is numerically investigated. Peculiarities of flow formation in the perturbed region due to a large initial angle of diffraction are revealed. The reasons for the appearance of the reverse flow over the cylindrical surface, which causes a vortex, are found. The influence of the vortex on the behavior of the loose end of the TU layer (slipstream) is studied. It is shown that the structure of the loose end of the TU layer is determined by vortex-related mixing in the gas. The nonstationary interaction of the diffracting shock wave and a sublayer shock with a concave cylindrical wall and the symmetry plane, which is accompanied by a change in the type of reflection, is examined. Published in Zhurnal Tekhnicheskoĭ Fiziki, 2007, Vol. 77, No. 10, pp. 24–33. The article was translated by the authors.