Published online by Cambridge University Press: 12 April 2006
This paper considers the case of a one-dimensional piston moving outwards with a speed proportional to rα and driving a strong shock into a non-uniform ambient gas whose density is initially proportional to r−k, k > 0. This problem is connected with that studied by Grundy & McLaughlin (1977), who effectively discussed the case α = 0. We discover further important uses of the Sedov similarity solutions and find kc, the upper limit to k for the shock path to be asymptotically similar to the piston path.