Abstract: The transonic separated flows around a pitching delta wing and vortex breakdown and aerodynamics characteristics are studied numerically. The results show that, the starting angle of attack of vortex breakdown is related to pitching speed very complicatedly, but doesn't change much in present calculation. The development of the bursting point in dynamic cases is very different from that in stationary cases. The unstable vortex and vortex breakdown are the main features of unsteady flow near the core of leading edge vortex around a delta wing at high incidence. When the pitching speed is high enough, the unsteady lift will higher than steady lift even at middle incidence, which will don't occur in incompressible cases. The pitching movement increase the stalling angle of attack, maximum lift and the lag between stalling and bursting angle of attack due to the vortex breakdown is delayed, but almost doesn't change the C L /C D .

Key words: maneuvered flight, unsteady flows, vortex-brea kdown, numerical simulation