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In this paper redesign process of an axial compressor of a Gas Turbine for mechanical drive is discussed together with computational results and experimental data. The goal of the project was to reduce compressor mass flow by 30% and at the same time to increase compressor specific work by about 10%. This could not be achieved by conventional methods such as re-staggering of Inlet Guide Vanes. Throughflow and CFD calculations were performed for redesigned versions. As a result an updated compressor was produced for the real engine and achieved design objectives. This paper shows how the swept area distribution along the compressor affects stage loading distribution and surge limits.

Several optimization approaches are presented in the paper, and the results of each task depending on the optimization setup are compared and discussed in terms of physical behavior and convergence. The optimization problem is set up and solved for several 2D compressor airfoils with different inlet parameters. The airfoils were generated and their characteristics were built for optimized solutions from different optimization approaches. The novel topology for 2D compressor airfoil is proposed and successfully utilized. The approach was tested for particular cases and showed a gain in efficiency and flow turning up to 15% (relative) compared with NACA-65 airfoils taken as the initial design.

The paper presents a study of corner separations in hub to blade region at various operation conditions towards compressor stall. It is known that for compressor flows with low or none separations computation fluid dynamics with RANS methods work quite well, however, for highly separated flows they are no longer entirely valid. Therefore, several criteria were applied for prediction and quantification of possible corner separation, and the main interest of this work is in predicting the separation just before it will actually happen by certain flow metrics, so these metrics can be further used as a ‘pre-stall’ criteria whilst the RANS CFD operating point still behave within its appropriate limits. Also the effect of shear lean is discussed in the presented context.