Abstract: In order to circumvent the problem of a huge amount of computing time required for solving viscous flows over bodies with complicated configuration using N-S equations, a mixed Euler/N-S solver was proposed. The solver is capable of preserving sufficient accuracy by using N-S equations in the flow field where viscous effects emerge as the dominant factor and employing Euler equations in the remaining regions. The primary scheme was constructed based on a high order entropy condition algorithm, in conjunction with an operator splitting concept deduced from theory of semi-group. The developed method was usedto simulate subsonic, transonic as well as supersonic flows over a mortar configuration. The numerical results were compared favorably with experimental data.