Abstract: Simulation of multi-medium compressible flows is generally on structured meshes. As triangular meshes provide a flexible way for decomposing a complex domain, we present an interface treating method for multi-medium flows on triangular meshes with a rGFM (real ghost fluid method). A level set function is used to capture interface. A Riemann problem is constructed at interface to provide fluid states. By defining interface boundary conditions with these states, calculation can be carried out as if in a single medium flow. A high-accuracy RKDG method is then employed to discretizing equations. Several examples are given to test robustness and efficiency of the algorithm. It shows that the method can capture sharp interface and shock wave accurately.

Key words: triangular meshes, RKDG method, multi-medium flow, real ghost nuid method, Riemann problem