Aerodynamic impacts of cold and hot blades in a transonic compressor rotor

Under the influence of aerodynamic loading and centrifugal forces， the elastic deformation of compressor rotor blades varies at different operation conditions. Utilizing a fixed hot blade for performance prediction in the full operation range significantly reduces the accuracy in aerodynamic calculation. This study primarily proposes an inverse computational method for determining the cold blade from a given hot blade and investigates the impacts of static elastic deformation （SED） on aerodynamic performance of compressor rotor blades in the full operation range. Firstly， the fundamental principles and implementation procedures of the iterative computational method based on fluid- structural interaction （FSI） for determining the cold blade are introduced. By regarding the geometry of the open reported hot blade as the target and its pressure distribution on the blade as the aerodynamic loading， the method starts from an initial cold blade and iteratively reduces the geometric deviation between the deformed blade and the original hot blade. The inverse calculation and accuracy verification results of the transonic compressor rotor， NASA Rotor 37 under the design operation condition indicate that this method requires only one flow computation of the original hot blade and the geometry of the resulting deformed blade obtained from iterative computation converges closely to that of the original hot blade， demonstrating both high computational efficiency and high accuracy. Subsequently， using the GS-FSI method， the performance characteristics in the full operation range of both the constant hot blade and the blade considering elastic deformation （FSI blade） of NASA Rotor 37 are calculated and compared. The analysis reveals that the performance characteristics of FSI blade exhibit significant differences with those of the constant hot blade. Comparing with the constant hot blade， elastic deformation results in positive twist of the FSI blade under the operation conditions with high mass flow rate， which reduces the mass flow rate， total pressure ratio and adiabatic efficiency. However， under the operation conditions with low mass flow rate， elastic deformation results in negative twist of the FSI blade， which increases the mass flow rate， total pressure ratio and adiabatic efficiency. Moreover， the total pressure ratio and adiabatic efficiency of the FSI blade show improved agreement with the experimental results.