RIEMANN SOLVER FOR RELATIVISTIC HYDRODYNAMICS

In this paper we construct an efficient, accurate, and rugged Riemann solver for relativistic hydrodynamics. The algorithm is an extension of the two shock approximation of Colella to the relativistic regime. The Riemann solver constructed here is made to converge to the solution via iteration. Two different iterative techniques are presented, one based on a secant method and the other on a Newton method. The method presented here provides an exact treatment of the transverse velocities across general, oblique shocks. This is a non-tirviall but very desirable property to have in a Riemann solver for relativistic flow. We also show the equivalence of our new formulation to the previous ones in the non-relativistic limit. (C) 1994 Academic Press, Inc.