倾转涵道倾转过渡阶段的非定常气动力

为研究倾转涵道动力装置在倾转过渡阶段的非定常气动力,使用基于滑移网格技术的非定常计算方法,利用基于内场信息和叶素理论的压力盘模型模拟风扇螺旋桨,通过求解Navier-Stokes(N-S)方程,对涵道风扇俯仰拉起过程进行数值模拟.结果表明:在倾转过程中涵道风扇非定常气动力的迟滞特性明显,俯仰角速度延迟了流场分离,增加了涵道风扇的升力和阻力;低速飞行时,涵道风扇在整个倾转过渡阶段气动性能优良;在高速大迎角飞行时,涵道风扇气动性能恶化,俯仰力矩曲线紊乱,不利于进行倾转过渡飞行. 

Unsteady aerodynamic force of tilt ducted fan during transition period

In order to study the unsteady aerodynamic force of the tilt ducted fan powerplant during transition period, a unsteady numerical simulation method based on sliding meshes was used. A disk model based on inner flow field information and blade element theory was utilized to simulate the fan propeller, and the Navier-Stokes (N-S) equations were solved to simulate the process of ducted fan during pulling up. The results demonstrate that the hysteresis properties of unsteady aerodynamic force of the ducted fan are obvious at transition period. The increase of pitch rate of the tilt ducted fan delayes the flow field separation, and increase lift and drag of ducted fan. The aerodynamic performance of the ducted fan is excellent in transition period at low speed. Higher speed and larger angles of attack worsen the aerodynamic performance of ducted fan, and the curve of the pitch moment is in a mess against the transition flight.