Far-field behavior of waves in a relaxing gas

An asymptotic equation is derived which describes the far-field behavior of the governing system of partial differential equations for a one dimensional unsteady plane and radially symmetric Bow of an inviscid relaxing gas; this evolution equation, is a generalized Burger's equation, which enables us to study in detail the various effects that appear in the propagation of plane, cylindrical and spherical waves in a dissipative medium with a quadratic nonlinearity. An approximate solution of this equation is obtained by using the method of matched asymptotic expansions; the method enables us to determine how the shock amplitude and the shift in the shock center are influenced by the relaxation effects. (C) 1997 Elsevier Science Ltd.