A novel method is developed for simulation of multi material compressible flows with arbitrary equation of state. The presented method is based on the idea of ghost fluid method in which a new EOS (equation of state) independent formulation is developed for populating ghost points. Assuming a three wave structure at the interface, by imposing the Rankin-Hugoniot jump condition across the fastest and the slowest wave, the intermediate Riemann states is estimated analytically at the interface. These Riemann states are used to populate ghost points. Employing 4 th order CWENO method as a base solver together with the presented ghost fluid method, the whole algorithm is independent of equation of state. Our new formulation is as capable as Riemann based GFM method in dealing with strong wave-interface interaction while enjoying the black box property for the equation of state. The capability of the proposed method is shown and tested via numerous one and two dimensional test cases including fluid-fluid and fluid-solid interface interaction with strong shock waves. In addition and based on the proposed method a completely Eulerian algorithm is developed for fluid- elastic-plastic solid interaction with large deformations. The governing equations for fluid and solid are considered to be fully nonlinear without any simplifying assumptions. Solid is assumed to behave as an Elasto-plastic material with Mie-Gruneisen equation of state. The algorithm solves fluid and solid equations simultaneously with the boundary conditions are imposed at the interface via proposed GFM method. Key words : Multimaterial flow, Ghost Fluid, Shock, interface, interaction, Equation of state, CWENO
