Experimental Compressor Multidisciplinary Optimization Using Different Parameterization Schemes

The multi-criteria and multidisciplinary optimization of the rotor and stator blades of the experimental compressor stage NASA Rotor 37 is carried out. For the optimization the unified parameterized multidisciplinary 3D model was specially made and used. This model includes the air-gas channel of the compressor stage and the finite element model of the rotor blade. This approach allows the consideration of different requirements for the aerodynamic, strength, and mass characteristics within one coupled optimization problem in unified computational space. The goal of this work is the analysis of different blade parameterization schemes and determination of optimum number of variable parameters for compressor stage aerodynamic characteristics improvement with respect to rotor blade static and dynamic strength. As an optimization criterions compressor stage efficiency and the blade mass minimization were used. Aerodynamic limits are: flow rate and pressure ratio values should not exceed base values more than ±0,5%. A static and dynamic strength limits are: maximum stress level should not exceed base level (the original design stress level) and the relative distance between the four natural frequencies and the nearest harmonics should not be less than 20%. As a result of optimization the NASA Rotor 37 version was found, which provide the efficiency increasing by approximately 2% and the blade centrifugal load decreasing by approximately 9%, while all aerodynamic and strength requirements are satisfied. It was also found, that increasing of the blade profile number of variables more than 7 is not rational.