Numerical inviscid vortex model applied to parallel blade-vortex interaction

In this paper a numerical inviscid vortex method is applied to the unsteady, two-dimensional and incompressible flow that occurs during a parallel blade-vortex interaction. We use a vorticity-panel method, where the airfoil bound vorticity is modeled as a discrete distribution of vortices having strength continuously and linearly distributed over the airfoil surface. The impermeability condition is satisfied on the airfoil surface, whereas the no-slip condition is not. The generation of the wake vorticity is accomplished with the equation of conservation of circulation and the application of the Kutta condition, which imposes the continuity of the pressure field at the airfoil trailing edge. The vortices shed into the flow to form the airfoil wake are convected downstream with the mean flow using a Lagrangian time-marching scheme. The main vortex that interacts with the airfoil is modeled as a potential vortex. The numerical results are compared to the experimental data of Straus et al. (1990), showing good agreement for the entire flow, except when the vortex is close enough to the trailing edge so that separation occurs.