双喷管STOVL飞行器升力突降动态过程的三维数值模拟

3-D numerical simulation of dynamic process of twin nozzle STOVL aircraft lift loss

针对双喷管短距/垂直起降(STOVL)飞行器升力突降问题,采用基于雷诺平均的k-ε湍流模型模拟STOVL飞行器气动流场,研究STOVL飞行器吸附力、附加升力对升力突降的影响.获得了稳、动态过程吸附力曲线,研究表明:吸附力由喷管外侧卷吸夹带流动产生的低压区决定,附加升力对升力突降的影响较小.在稳态过程无量纲高度小于3.5,吸附力占飞行器升力10%以上.对比稳、动态过程,发现动态过程吸附力大于稳态过程,在无量纲高度为2时,两者相差最大,为20.6%.主涡的运动和发展迟滞是造成稳、动态过程吸附力差异的原因.

For twin nozzle short take off and vertical landing （STOVL） aircraft lift loss, Reynolds-averaged turbulence k-s model was employed to simulate the aerodynamic flow field of STOVL aircraft and its lift loss. The effects of suck down and additional lift of STOVL aircraft on lift loss were studied, and curves of suck down during steady and dynamic proces- ses were acquired. Results showed that suck down mainly depended on low pressure area generated by entrained flow, and additional lift had little effects on lift loss. When dimen- sionless height was lower than 3.5, suck down was larger than 10% of the aircraft lift. Dy- namic and steady processes were compared, and suck down in the dynamic process was grea- ter than that in the steady status, especially at dimensionless height 2, nearly 20.6% differ- ence. The movement and development delay of main vortex was the cause of this difference of suck down during steady and dynamic processes.