非对称入流对“螺旋桨/机翼”系统气动特性的影响

针对“螺旋桨/机翼”系统在复杂非对称入流情况下的非定常气动相互干扰问题，采用混合结构-非结构滑移网格方法，结合非定常雷诺平均Navier-Stokes方程，研究了偏航角及入流条件（包括攻角和来流风速）对螺旋桨/机翼相互气动干扰和滑流流场的影响，并与无滑流模型计算结果进行对比。结果显示：在三维非对称入流的影响下，偏航角从0°增加到20°时，机翼升、阻力系数分别降低了4.9%和10.64%，但是螺旋桨的拉力系数和推进效率则大幅提升了18.36%和7.26%，非对称入流机翼升力系数曲线变化幅度为对称入流的4倍。在攻角不变，改变偏航角时，螺旋桨滑流增加了机翼俯仰力矩稳定性裕量。但是随着攻角的变化，飞机纵向不稳定性逐渐增加，在桨后气流的影响下，两侧机翼上表面吸力峰均向左和向前移动，上下表面的吸力峰值均明显增大。在不同的风速下，有滑流影响的机翼升力特性相对无滑流影响的机翼增加量均在20%附近，且不断增大。

Influence of propeller/wing system on aerodynamic performance at asymmetrical inflow

In order to address the problem of the unsteady aerodynamic mutual interference of propeller/wing system in cases of complex asymmetrical inflow, the hybrid structured-unstructured sliding mesh method combined with the unsteady Reynolds-averaged Navier-Stokes equation was used. This approach assessed the influences of yawed angel and inflow conditions (e.g., angle of attack and freestream velocity) on mutual aerodynamic interference of the propeller/wing and the propeller slipstream, and compared with the calculation results of the no-slipstream model. The results revealed that under the influence of three-dimensional asymmetric inflow, the wing lift coefficient and drag coefficient fell by 4.9% and 10.64%, respectively, when the yawed angle increased from 0° to 20°. However, the thrust coefficient and propulsion efficiency of the propeller improved significantly by 18.36% and 7.26%. Additionally, the fluctuation range of the lift coefficient of the asymmetrical inflow was four times that of the symmetrical inflow condition. When the angle of attack remained constant and the yawed angle changed, the propeller slipstream enhanced the stability margin of the wing pitching moment. Unfortunately, with a fluctuating angle of attack, the longitudinal instability of the wing gradually increased. Meanwhile, under the influence of the airflow behind the propeller disk, the suction peaks on the upper surface of the wing on both sides of the nacelle moved leftward and forward, while the absolute values of the peak on both the upper and lower surfaces increased considerably. With varying wing speed, the increase in wing lift performance with slipstream was around 20%, compared with the wing without the influence of slipstream. Besides, the lift performance continued to increase with wind speed.