The reflection of a plane shock wave over a double wedge

An analysis is presented of the shock wave configurations which will occur when a plane shock is incident on a double wedge for which the second wedge may have a greater (concave case) or a smaller (convex case) inclination than the first wedge. It is shown that seven different reflection processes may be expected depending on the Mach number of the incident shock M_i and the two wedge angles 0^ and 0%,. These processes may be defined by seven regions in the (θ¹_W θ²_W)-plane, for a given value of M_i. Each of the seven processes has been verified by sequences of shadowgraph and schlieren photographs. A shock polar analysis of each of the seven processes has provided information about the pressure changes and the wave structures which develop immediately behind the main reflections along the wedge surfaces. These wave structures have been verified experimentally, and two types have been observed: one normal to the reflecting surface, and the other in the form of a regular reflection. The criteria to determine which of these configurations will occur have not yet been established. It is believed that the present study will be of value in predicting the loading of shock waves on structures, and may lead to a better understanding of shock reflections from concave and convex cylindrical surfaces.