一种分布式电动飞机螺旋桨滑流影响机理

提出了一种分布式电推进螺旋桨飞机，采用二阶精度求解RANS方程的k-ω SST （Shear-Stress-Transport）湍流模型，基于多参考系（MRF）方法，针对低速特性进行数值模拟，得到了分布式螺旋桨滑流效应对全机气动特性的影响规律，重点对螺旋桨后方速度场及机翼表面压力分布进行分析。结果表明有滑流状态增加了全机升力和阻力，升力系数最大增量超过65%，且升力增量随迎角的增加而增大，改善了失速性能，增加了低头力矩；螺旋桨旋转增加了周向速度，改变了径向速度分布，增加轴向速度，高能量螺旋桨滑流改变了机翼当地升阻力特性；螺旋桨桨叶向上旋转一侧气流受上洗影响而局部迎角增加，另一侧局部迎角降低，越靠近桨盘位置，受螺旋桨洗流带来的影响越大；螺旋桨的旋转方向对螺旋桨两侧的机翼表面压力分布有较大影响，尤其是翼尖螺旋桨对全机气动性能影响较大。

Influence mechanism of propeller slipstream on wing of a distributed electric aircraft scheme

This paper proposes a kind of distributed electric-propelled propeller aircraft, which uses the second-order precision k-ω Shear-Stress-Transport (SST) turbulence model to solve the RANS equation, and uses the Multiple Reference Frame (MRF) method to carry out numerical simulation for the low-speed characteristics, and this paper obtains the influence of the distributed propeller slipstream effect on the aerodynamic characteristics of the entire aircraft. The results show that the slip flow state increases the lift and drag of the whole aircraft, the maximum increment of lift coefficient is more than 65%, and the lift increment increases with the increase of angle of attack. The slip flow improves the stall performance, and increases the head-down moment. Meanwhile the rotation of the propeller increases the circumferential speed, changes the radial speed distribution, increases the axial speed, and the high-energy propeller slipstream changes the local lift and drag characteristics of the wing; the result also shows the airflow of the propeller blades rotates upwards, and the local angle of attack increases due to the up washing effect on one side, while the local angle of the attack on the other side decreases. The rotation direction of the propeller has a great influence on the surface pressure distribution of the wing on both sides of the propeller; especially the wingtip propeller has a great influence on the aerodynamic performance of the whole aircraft.