Applying Vortex Breakdown Empiricisms to Predict Aerodynamic Characteristics in Symmetric and Asymmetric Situations

On manoeuvrable aircraft manned or unmanned, it is imperative to understand the onset of wing vortex flows and their breakdown. The applications are for military and civil types featuring moderate to high sweep. An understanding of vortex flows is also required from the viewpoint of control, LE & TE devices. Quantitative information and understanding is needed on vortex flows e.g. forces, moments and loadings so as to either exploit them or avoid them. Further, symmetric and asymmetric effects are both required. The challenge here is to predict forces and moments on a wing-body (deltas or swept trapezium wings of moderate taper, cambered, rounded LE) operating with large side-slip throughout full α range with Mach and Reynolds number effects. To address many geometric variables, a reasonably quick turn-around is required. This paper is via the initiative of the RTO-AVT Task group AV-080. In this "condensed" version, results from an approach are presented that has attempted to model such effects for a series of 53° and 58° swept trapezium wings.