MECHANISMS AND ACOUSTICS OF BLADE-VORTEX- INTERACTIONS

Paper presents results from a numerical study of Indices blade-vortex interaction (BVI) aerodynamics and acoustics. A two-dimensional model problem was used to do the flow simulation using an Euler- and a Navie r-Stokes code. For the turbulent calculations an algebraic Baldwin-Lom ax and the two-equation k-epsilon turbulence model was used. The acous tic features of BVI in the near- and midfield were analysed with the f low simulation code and the far-field results were obtained using the three-dimensional Kirchhoff's method. Several crucial parameters of BV I, such as vortex strength, vortex miss distance and the free stream M ach number were varied. The main difference between the inviscid and t he viscous flow consideration are pointed out. A comparison with exper imental data is done for the important case of a head-on collision.