A REVIEW OF APPROXIMATE RIEMANN SOLVERS WITH GODUNOV METHOD IN LAGRANGIAN COORDINATES

This paper constructs several approximate Riemann solvers for use in s olving the fluid flow equations in Lagrangian coordinates (the overall solution procedure used here is Eulerian with a Lagrangian step follo wed by a remap to the original coordinates). Results obtained with the se solvers are compared with exact or converged numerical solutions to define their characteristics. The Riemann solvers developed here are useful in flow solution algorithms involving a Lagrangian-Eulerian or purely Lagrangian formulation.