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Article

Focusing of strong shocks in an elliptic cavity

Authors: Apazidis, N.
Document Type: Article
Pubstate: Published
Journal: Shock waves
Volume: 13   91-101
Year: 2003

Abstract

Focusing of strong shock waves in a gas-filled thin chamber with an elliptic boundary is investigated theoretically and numerically. The process of reflection and convergence of cylindrical shocks generated at one of the focal points of the chamber is studied by means of Whitham`s theory of geometrical shock dynamics (1957, 1959). The current calculations are based on the modified version of this theory, which takes into account the nonhomogeneous flow ahead of the advancing shock, Apazidis & Lesser (1996). There are two main results of the present study indicating a qualitatively different behavior of strong shocks as compared to the linear acoustic case. (1) - the form of thereflected shock is not cylindrical and (2) - the reflected, converging shock does not focus at the geometrical second focal point of the chamber. The dependence of the form of the reflected shock and the location of its focusing point on the strength of the shock and the eccentricity of the chamber is investigated.