舰载倾转旋翼机着舰域耦合流场数值模拟研究

Coupled flow field numerical simulation study of ship-borne tilt-rotor aircraft landing area

倾转旋翼机是当前旋翼飞行器研究的热点,但有关舰载倾转旋翼机着舰域耦合流场的研究还很少。以两栖攻击舰(LHA)和V-22"鱼鹰"倾转旋翼机为研究对象,基于雷诺平均Navier-Stokes(RANS)方程和SST k-ω湍流模型对舰载倾转旋翼机着舰域耦合流场进行数值模拟研究,并探讨了不同着舰高度时机/舰耦合流场的相互作用。结果表明:倾转旋翼尾流会与舰船脱落涡、甲板舷涡以及舰岛艉涡发生较强的"涡-涡干扰"现象,加大了耦合流场的湍流强度;舰船流场的低频非稳态特征会导致旋翼桨盘气动载荷发生显著的波动,不利于飞行操纵;垂直降落过程中,舰船甲板会形成"前低后高"的压力分布特征,倾转旋翼RMS气动载荷值也会明显增加,降低了着舰安全性,且右旋翼RMS气动载荷值比左旋翼平均大一倍以上,这也表明右旋翼面临着更加严峻的气动环境。

Tilt-rotor aircraft is a hotspot in the research of rotorcraft at present, but there are few studies on the coupled flow field of ship-borne tilt-rotor aircraft. Taking the LHA ship and V-22 "Osprey" tilt-rotor aircraft as the research objects, the numerical simulation of coupled landing flow field was carried out based on the Reynolds average Navier-Stokes(RANS) equation and SST k-ω turbulence model. The interaction of coupled landing flow field at different landing heights was discussed then. The results show that the vortice-vortice interaction between the tilt rotor wake, ship shedding vortices, the deck side vortices and the island’s stern vortices increases the turbulence intensity of coupled flow field. The low-frequency unsteady characteristics of the ship flow field can cause significant fluctuations in the aerodynamic loads of the rotor disk, which is not favorable to flight control. During the vertical landing process, the ship deck can form a "front low back high" pressure distribution characteristic, and the RMS aerodynamic load of tilt rotor increases significantly, which reduces the landing safety. Moreover, the RMS aerodynamic load of the right rotor is more than twice than the left, which also indicates that the right rotor faces a more severe aerodynamic environment.