振荡射流提高翼型升力的机理研究

INVESTIGATION OF MECHANISM OF PROFILE-LIFT INCREASE BY OSCILLATING EXCITATION

本文数值模拟了施加振荡射流以及相应定常吸气条件下的翼型分离流动。对振荡射流改善翼型升力的机理进行了研究。结果表明,翼型表面施加的振荡射流能够控制流动分离的形态,提高分离区流体的湍流度,增强分离区内部流体,以及与主流的动量和能量交换,增强近壁区流体的动能,降低翼型吸力面压力,而对压力面无显著影响,因而翼型的升力得到提高。

The flow fields around a profile at a large attack angle with/without oscillating/steady excitation at the profile's leading edge have been numerical simulated. The lift-increase mechanism by the oscillating excitation has been investigated. The results indicated that the oscillating excitation at the surface of the profile totally changes the structure of separation flow vortex, improves the turbulent intensity of the separated flow so that the momentum and kinetic energy of the flow near the profile suction surface has been increased and its pressure has been decreased. At the same time, the oscillating excitation has little influence on the profile pressure surface. Therefore, the lift of the profile is increased.