An exact Riemann Solver for multidimensional special relativistic hydrodynamics

We have generalised the exact solution of the Riemann problem in special relativistic hydrodynamics for arbitrary tangential flow velocities. The solution is obtained by solving the jump conditions across shocks plus an ordinary differential equation arising from the self-similarity condition along rarefaction waves, in a similar way as in purely normal flow. The dependence of the solution on the tangential velocities is analysed. This solution has been used to build up an exact Riemann solver implemented in a multidimensional relativistic (Godunov-type) hydro-code.