On the Role of Leading-Edge Bumps in the Control of Stall On-Set in Axial Fan Blades

B3 - Unsteady Aerodynamics and Flow Simulations

Biologists have associated the capability of the humpback whale to execute very sharp rolls and loops under water with the presence of bumps on the leading edge of their flukes that work as a stall-control system. Taking a lead from the humpback whale flukes, this paper reports on a three-dimensional numerical study of sinusoidal leading edges on cambered airfoil profiles. The authors computed the turbulent flow around the cambered airfoils at different angles of attack with the open source solver OpenFOAM and an isotropic eddy viscosity model integrated to the wall. The reported research focused on the effects of the modified leading edge in terms of lift-to-drag performance. The research was primarily concerned with the elucidation of the fluid flow mechanisms induced by the bumps and the impact of those mechanisms on airfoil performance.