Effects of the low Reynolds number on the loss characteristics in an axial compressor

Abstract

As the gas turbine becomes smaller and is operated at high altitude, the aerodynamic condition frequently lies at the low Reynolds number. In the present study, three-dimensional computations were performed to understand the effects of the low Reynolds number on the loss characteristics in an axial compressor. The numerical results showed that the performance of the axial compressor like the static pressure rise is reduced by the full-span separation on the suction surface and the boundary layer on the hub, caused by the low Reynolds number. Compared with that at the reference Reynolds number, the total pressure loss at the low Reynolds number was found to be greater from the hub to 85 per cent span and smaller above the 85 per cent span. For a detailed analysis, the total pressure loss was scrutinized through three major loss categories available in the subsonic axial compressor: profile loss, tip leakage loss, and endwall loss.