Tunable Dual-Wavelength Erbium-Doped Fiber Ring Laser

A novel technique regarding the reduction of helicopter blade-vortex interaction noise is proposed. The proposed technique is based on the idea of injecting air at the leading edge of the blade to alter the vortex characteristics (strength and core size). The numerical investigations are performed using the large-eddy simulation (LES) approach. The simulations were performed for a Reynolds number, Re = 1.3 x 106, based on the NACA0012 airfoil chord and free-stream velocity. The present study shows that by injecting air at the leading edge of the blade, the influence of blade-vortex interaction on the aerodynamic coefficients and aeroacoustic noise is significantly reduced. © 2012 by Marcel Ilie. Published by the American Institute of Aeronautics and Astronautics, Inc