Sting Effects on Transonic Delta Wing Experiments

Abstract : It has been observed that delta wings placed in a transonic freestream can experience a sudden movement of the vortex breakdown location as the angle of incidence is increased. The current paper uses CFD to explain this behaviour in detail. The study shows that a shock-vortex interaction is responsible, with the shock arising from the presence of a sting in the supersonic flow over the wing. The balance of the vortex strength and axial flow, and the shock strength, is examined to provide an explanation of the sensitivity of the breakdown location. Limited experimental data is available to supplement the CFD results in certain key respects, and the ideal synergy between CFD and experiments for this problem is considered.