Wave Patterns in the Interaction of an Incident Shock with an Elliptic Gas Cylinder

The wave patterns in the interaction between a planar incident shock and an elliptic gas cylinder are studied by two-dimensional Eulerian simulations. The finite volume weighted essential non-oscillatory (WENO) scheme with interface and shock-capturing algorithm is employed. The aspect ratio of the heavy/light elliptic gas cylinder ranging from 0.25 to 4.0 is defined as the ratio of streamwise length to spanwise length. For the heavy cases, numerical results show that the transmitted shock splits in the cylinders with aspect ratio less than one while reflects in the cylinders with aspect ratio greater than one. On the other hand, for the light cases, the wave patterns are similar, and the interaction time is relatively short. As the incident shock propagates downward, the wave patterns change from “free precursor refraction” to “twin von Neumann refraction” in the light cases. Irrespective of cylinder gas species, the greater aspect ratio results in more primary circulation deposition, and the normalized linear deposition rate is nearly the same for different aspect ratio cases.