Numerical simulation of shock/vortex interaction in transonic flow around a delta wing

It is observed that delta wings placed in a transonic flow can experience a sudden upward movement of vortex breakdown location as the angle of attack is increased, which is different from the case with subsonic flows. To investigate this flow phenomenon, transonic flows around a 65° swept leading edge delta wing are numerically simulated by solving Reynolds average Navier-Stokes (RANS) equations coupled with a rotation corrected Spalart-Allmaras (SAR) turbulence model. In addition to steady simulations, calculations using detached eddy simulation (DES) based on the SAR turbulence model in the time accurate flow are performed, in which the normal shock movements on the top surface of the delta wing and the corresponding leading edge vortex breakdown locations are preliminarily studied. A comparison with experimental data shows that the simulations based on the SAR model simulate the shock wave system and vortex structures accurately, and capture the phenomena of sudden upward movement of the vortex breakdown location due to shock wave interaction. Additionally, the unsteady simulation of post-breakdown flow shows that, because of the interaction of the normal shock ahead of the sting tip, the location of vortex breakdown moves downstream abruptly while the upstream movement is relatively slow.