Critical aerodynamic aspects of helicopter blade-vortex interaction; A numerical study using large-eddy simulation

Numerical investigations of helicopter blade-vortex mechanism of interaction are performed using large eddy simulation (LES). The simulations were performed for a Reynolds number, Re = 1.3 × 10⁶, based on the chord, c, of the airfoil (NACA0012). Computations are carried out for two different types of blade-vortex interactions, concerning single and respectively two vortices blade interaction. It was observed that for single vortex-blade interaction, the blade-vortex interaction becomes less significant with the increase of vertical miss distance. Larger amplitudes of aerodynamic coefficients were observed for the case of two vortices-blade interaction when compared with the single vortex blade interactions.