Aerothermodynamics optimal design of a multistage axial compressor in a gas turbine using directly manipulated free-form deformation

The compressor global geometric model including the endwall and the blade is parameterized based on a directly manipulated free-form deformation (DFFD) approach. A meridional flow streamline curvature method for solving inverse and forward problems is applied to the reverse design and performance analysis of the compressor. Combined with an improved Powell search algorithm and the multi-island genetic algorithm, a platform for the fast aerodynamic optimal design of the multistage axial compressor is established. The integrated automatic design and performance optimization of a nine-stage axial compressor in a gas turbine are performed. Meanwhile, the inlet transition section, strut and outlet expansion section of the compressor are retrofitted and optimized considering the connection with the front and rear of the test section. The result indicates that the platform can automatically and effectively realize the process of the fast design, analysis and optimization for the multistage axial compressor. Finally, the total pressure ratio and adiabatic efficiency at the design point and the surge margin at the design rotate speed are 5.057, 88.16% and 17.25%, which are 0.377%, 1.043% and 1.173% relatively higher than those before the 3D DFFD optimization respectively.