Slender wings with leading-edge vortex separation - A challenge for panel methods and Euler solvers

The demands of performance and maneuverability on modern fighter aircraft and missiles require slender wings, whose leading edge vortex flows result in increased lift at high angles of attack This paper reviews the history of the utilization of these vortex flows, and the development of theoretical methods for prediction of the nonlinear characteristics of slender wings Possible improvements based on the integral physical effects of the vortex flow are also considered Recent advances in the numerical solution of the time dependent Euler equations make Euler methods an attractive alternative to the methods based on potential flow solution ap proaches The latter are usually limited to subsonic speeds and demand as much effort to predict the flow around more complex configurations as do the Euler methods The latter even are able to predict flow separation effects to some extent, providing significant support for the evaluation of more complex shapes, thus improving the design procedures Results obtained by a panel procedure and by an Euler method are presented for different wings and wing body configurations Preliminary results obtained by applying these methods to vortex breakdown are included