Advanced Axial Compressor Airfoils Design and Optimization

Abstract

Advanced compressor airfoils design and optimization have been investigated for the axial compressor of gas turbine at high subsonic condition, which aim to decrease losses and to increase compressor operating ranges. The design and optimization processes are carried out based on (CDP_HEU) the Compressor Design Platform of Harbin Engineering University, in which a geometric code for the airfoil description, grid generation, blade-to-blade solver and the interface codes were combined. The influence of the higher airfoil Reynolds numbers flow of the land/marine based compressors is compared with aero engine and the impact of these differences on the location of boundary layer transition are taken into account by γ-Reθ transition model in ANSYS/CFX solver. The optimization objective function is a compromise of the total pressure losses at design-point and at off-design conditions of a large incidence angle range. The effects of optimization variables selection, objective functions and numerical optimization algorithms on the design results are analyzed and discussed in this paper. The superior performance of the optimized airfoil is demonstrated by a comparison with conventional controlled diffusion airfoils (CDA) at a wide range of inlet flow angles, inlet Reynolds numbers and inlet Mach numbers that maximum value can reach 0.77. The aerodynamic advantage of the optimized airfoils have been presented, which include the leading edge shock wave losses and the profile losses etc. The optimized results indicate that a significant improvement in compressor efficiency and stability for land/marine gas turbine could be reached by the proposed optimized airfoils instead of conventional airfoils. Moreover, different optimized variables, objective function and optimization algorithm are recommended which could improve the optimization efficiency remarkably with the same design effect.