A centrifugal compressor has been evaluated numerically for the scalability of aeroelastic parameters for different pressure levels. By maintaining the flow coefficient, as done in the development process, comparable aerodynamics for the compressor cases have been generated ranging from 0.96 bar to 40 bar inlet pressure. It has been found, that the mean static pressure as well as the aerodynamic damping can be scaled by the inlet density ratio. The gained results proofed for this case to be sufficient in magnitude and distribution for an early development stage. Harmonic pressure scaling for centrifugal compressors however has resulted in non-negligible errors. The origin of changes for the setup presented is found in the variation of Reynolds number. Especially the hub and tip sections are influenced and therefore also the secondary flow through the impeller tip gap. This generally results in lower scalability after the transition from axial to radial flow. Hence impeller trailing edge mode shapes have to be considered carefully. The Reynolds number effects become smaller however for higher temperature levels, reducing the scaling errors.
High-Reynolds-number effects on turbulent scalings in compressible channel flow
