Effect of surface roughness on the aerodynamic performance of turbine blade cascade

The effect of surface roughness on the boundary development and loss behavior of turbine blades is investigated with different Reynolds numbers in this paper. The result shows that the velocity profile in boundary layer is plumper on rough surface than on smooth blade. The aerodynamic loss is lowered at low Reynolds number, but becomes significantly large at high Reynolds number. The total pressure loss coefficient of cascade can reach a top increase of 129% for rougher blades comparing with smooth blades at Re=300000.