Abstract
Three-dimensional numerical simulations were conducted to understand the effects of low Reynolds numbers on the performance of a transonic axial compressor. For the reference case, the computational results showed good agreement with the experimental data in total pressure ratio and exit flow. With decreasing Reynolds number, the mass flow rate and total pressure ratio of the axial compressor decreased by 4% and 1%, respectively, in comparison to the reference case. This study found that large viscosity significantly affects the location and intensity of the passage shock, which moves toward the leading-edge at low Reynolds numbers. Additionally, these results successively revealed changes in internal flow pattern such as pressure distribution on the blade surface, tip leakage flow and separation. An attempt has been made to explain the dependence of the performance and the total pressure loss on the Reynolds number in a one-stage transonic axial compressor. In addition, it was confirmed that there is a critical Reynolds number around 250,000 in axial compressors, below which total pressure loss increases rapidly.
