Investigation of the F117A Vortical Flow Characteristics Preliminary Results

The investigation of the vortical flow around the F117A Stealth Fighter is presented in order to demonstrate the capability to resolve leading edge vortices with an adaptive finite element solver for the Euler equations. The major goal is to capture vortex breakdown at high angles of attack. This work presents the five main steps involved in a typical study of the flow characteristics of a complete aircraft : the definition of the model geometry, the realization of a suitable grid around the discretized model, the implementation of a flow solver, the subsequent analysis of the flow field and the comparison to experimental data sets. The computational data are compared to the lift curves of the aircraft obtained in a subsonic 5' x 7' wind tunnel. The occurance and location of vortex breakdown is determined by performing flow visualization in the tunnel. Five cases are computed for this work. Each case is studied at Mach 0.3 and angles of attack range between 7 and 30 degrees