Front Tracking algorithms have generally assumed that the computational medium is divided into piece-wise smooth subdomains bounded by interfaces and that strong wave interactions are solved via Riemann solutions. However , in multidimensional cases, the Riemann solution of multiple shock wave interactions are far more complicated and still subject to analytical study. For this reason ,it is very desirable to be able to track contact discontinuities only. In this paper , we describe a new numerical algorithm to couple a tracked contact surface and an un tracked strong shock wave. The new tracking algorithm reduces the complication of computation , and maintains the sharp resolution of the contact surface. The numerical results are in good agreement.
