Comparison of two explicit Euler solvers with a hybrid approach to calculate transonic cascade flows with embedded shocks.

Numerical methods for calculating mixed subsonic/supersonic flows by solving the Euler equations are an integral part of transonic turbine design systems. There are some problems when using an Euler solver: the lack of conservation the total pressure in subsonic regions, the failure of predicting accurately shock intensity and losses and a rather long computing time. At present the method of characteristics is still the only method to provide an accurate solution of supersonic flow fields. Hence a combination of this method with an Euler solver, providing correct starting conditions in the throat region, can help to overcome these problems. In this paper two different Euler solvers will be discussed and the hybrid method combining an Euler code with the method of characteristics are presented.