倾转旋翼机巡航状态旋翼滑流影响

倾转旋翼机由于需要兼顾垂直起降和高速平飞2种典型工况下的动力需求，采用大直径旋翼作为推进装置会使机翼大部分处于旋翼滑流区内，这与常规螺旋桨飞机存在较大差异。为评估不同数值计算方法并研究旋翼滑流对倾转旋翼机气动特性的影响，针对选取两叶旋翼的某倾转旋翼机方案，利用激励盘模型、多参考系（MRF）模型、滑移网格模型分别进行了巡航状态下旋翼滑流对全机气动特性影响的数值模拟研究。结果表明:相对于无滑流状态，滑流定常影响使全机阻力增大，最大升阻比降低了7.5%，尾翼产生的升力增大，纵向静稳定度增加了17.1%，全机低头力矩增大；当迎角较小时，滑流虽然改变了机翼表面的升力分布，但是全机升力变化不大；滑流非定常影响会使全机气动特性产生周期性波动，升力系数波动幅度为9.0%，阻力系数波动幅度为10.8%，并且随着迎角的增大，波动幅度也越大。 

Effect of rotor slipstream of tiltrotor aircraft in cruise mode

The tiltrotor aircraft needs to take into account the power requirements of vertical takeoff and landing and high-speed level flight, and using large diameter rotor as the propulsion device will make most of the wing in the rotor slipstream area, which is different from the conventional propeller aircraft. In order to evaluate different numerical methods and study the effect of rotor slipstream on the aerodynamic characteristics of a tiltrotor aircraft with two-blade rotor in cruise mode, the actuator disk model, the Multiple Reference Frame (MRF) model and the sliding mesh model are used respectively for numerical simulation study. The results show that, compared with no slipstream, the steady effect of slipstream increases the drag of the whole aircraft, and the maximum lift-drag ratio decreases by 7.5%. The lift generated by the tail wing is increased. The longitudinal static stability is increased by 17.1% and the pitch down moment of the whole aircraft is increased. When the angle of attack is small, although the slipstream changes the lift distribution on the wing surface, the lift of the whole aircraft does not change much. The unsteady influence of the slipstream causes periodic fluctuation of the aerodynamic characteristics of the aircraft. The fluctuation range of lift coefficient and drag coefficient are 9.0% and 10.8% respectively. With the increase of the angle of attack, the fluctuation range also increases.