RT Journal Article T1 Control of the separated flow around an airfoil using a wavy leading edge inspired by humpback whale flippers A1 Favier, J. A1 Pinelli, Alfredo A1 Piomelli, U. AB The influence of spanwise geometrical undulations of the leading edge of an infinite wing is investigated numerically at low Reynolds number, in the context of passive separation control and focusing on the physical mechanisms involved. Inspired by the tubercles of the humpback whale flippers, the wavy leading edge is modeled using a spanwise sinusoidal function whose amplitude and wavelength constitute the parameters of control. A direct numerical simulation is performed on a NACA0020 wing profile in a deep stall configuration (α=20°), with and without the presence of the leading edge waviness. The complex solid boundaries obtained by varying the sinusoidal shape of the leading edge are modeled using an immersed boundary method (IBM) recently developed by the authors [Pinelli et al., J. Comput. Phys. 229 (2010) 9073–9091]. A particular set of wave parameters is found to change drastically the topology of the separated zone, which becomes dominated by streamwise vortices generated from the sides of the leading edge bumps. A physical analysis is carried out to explain the mechanism leading to the generation of these coherent vortical structures. The role they play in the control of boundary layer separation is also investigated, in the context of the modifications of the hydrodynamic performances which have been put forward in the literature in the last decade. PB Elsevier France-editions Scientifiques Medicales Elsevier SN 1631-0721 YR 2012 FD 2012 LK https://hdl.handle.net/20.500.14352/43877 UL https://hdl.handle.net/20.500.14352/43877 LA eng DS Docta Complutense RD 28 abr 2024