Numerical Simulation of Two-Dimensional Parallel Blade-Vortex Interactions Using Large Eddy Simulation

AbstractIn this paper, an unsteady, two-dimensional, parallel blade-vortex interaction (BVI) has been calculated using large eddy simulation (LES) and the predicted pressures are compared with experimental measurements. The BVI is a primary source of rotor vibratory loading and rotorcraft noise. The LES technique provides a promising tool for obtaining the unsteady wall-pressure fields, aerodynamic coefficients, and acoustic functions. The dynamic sub-grid scale stress model, the low diffusion Roe flux-difference splitting scheme, and second order accuracy in the time and space are used. The simulation was performed for Mtip= 0.714 and Re = 2.2e6, on a case where the miss distance equals 0, which will be referred to as a strong BVI. The simulation was first run until a unsteady compressible fully-developed turbulent flow field was achieved for the non-lifting NACA 0012 airfoil. Then, the Scully vortex, which has been widely used, was added to the fully-developed turbulent flow field as a perturbation. In the present computation, the spatial resolution close to the surface was very good. The wall y+ was smaller than 0.6. The LES method can accurately preserve the characteristics of the vortex. The simulation which was low dissipative had a good agreement with the experimental results (C. Kitaplioglu, 1999). Moreover, the vortex had an important influence on the aerodynamic performance of the blade