Application of Analytical and Numerical Methods for the Design of Transonic Axial Compressor Stages

Usually, the first stage of a compressor of a gas turbine works in the region of transonic flow, so that the designer has to take into account a lot of flow details like shocks, boundary layer separation and their interaction, when a new machine is defined. Beside other problems the choice of the blade geometry and profile family is one important consideration. For the design of the blades analytical and numerical methods are applied, but there is always a difference in their results, because the analytical methods are based on simplified assumptions and the numerical techniques make use of turbulence models. So the question arises: How large is the difference between the analytical and numerical results? This is theme of the following contribution. Key-Words: Transonic Flow, Analytical and Numerical Calculation Techniques, Shocks, Unique-Incidence-Condition