Experimental and numerical investigation on aerodynamic performance of biomimetic blade in steam turbine

Abstract

Low load condition will cause the flow field in steam turbine to be complex, affecting the aerodynamic performance. We propose a biomimetic blade with bumpy leading edge to achieve better performance in low mass-flow conditions. The bumps on leading edge are inspired by the flipper of humpback whale. Both experiments and numerical simulation are conducted to discuss the function and mechanism of the biomimetic blade. The results from the experiment and simulation show high consistency. There exists a radial vortex on pressure side of original blade, blocking the energy exchange between blade and main flow. The bumpy leading edge generates streamwise vortex pairs to suppress the radial vortex. For the biomimetic blade, the pressure side from leading edge to the middle region has higher applied pressure because the streamwise vortices remains. The inlet flow pressure and the angle of attack have a significant influence on the vorticity of streamwise vortices. These two parameters should be in a certain range. The best value is inlet pressure of 1.09P0 and angle of attack of −40°. The current work uncovers the mechanism of bumpy leading edge in flow control and provides a new design for turbine blade.