Numerical analysis of aerodynamic characteristics of a bumped leading edge turbine blade

This paper investigates the aerodynamic effects of waving bumps inspired by a humpback whale fin on the leading edge of a turbine blade. A comparison was made between performances of two isolated blades: a blade with a sinusoidally shaped bumped leading edge (LE) and one with a straight leading edge; both based on the same NACA0012 cross section profile. The simulations used a Reynolds number of 1.8·10^5 for a range of angles of attack from 0o to 30o. The results for the bumped blade have shown a substantial gain in aerodynamic characteristics for certain angles of attack (AoA). At AoA larger than 10o, the bumped blade has shown an increase in lift (3%-9.5%) and decreased drag, while negligible differences in lift and a smaller drag were exhibited for AoA smaller than 10o. Overall, the bumped blade provided greater advantage in lift to drag ratio (approximately 50%) over the AoA range from 0o to 20o. The sinusoidal leading edge also delayed the stall crisis, increasing the critical angle of attack by approximately 5o over the one for the blade with a straight leading edge.