风向对直升机旋翼与甲板流场结构影响

Influence of wind directions on the flow field structures of helicopter rotor and deck

为了了解直升机旋翼流场与甲板流场的相互作用,采用数值模拟方法对船体与旋翼的复合流场进行求解.分析了不同风向时旋翼流场的流线形态、涡量分布与旋翼平衡性.详细阐述了复合流场中主要旋涡结构的产生及演变过程,并对旋涡结构进行分类.研究结果表明:旋翼流场与甲板流场间存在相互干扰,形成复杂的复合流场.0°风向时,旋翼的存在使得其后方甲板区域的涡流范围与气流下洗趋势增加明显;侧风会增大甲板区域涡流范围,加剧旋翼桨叶不平衡性;右舷15°风向时,旋翼升力能力与旋翼桨叶平衡性最差,该风向不利于直升机的甲板悬停.

In order to study the interaction between helicopter rotor and deck flow fields,numerical simulation was carried out on a composite flow field made up of ship and rotor.Streamline patterns,vorticity distribution,and balance of the helicopter rotor with different wind directions were analyzed.The appearance and evolution of the main vortex structures were elaborated and the vortex structures were classified.Simulation results show that,the rotor and the deck interfere with each other＇s flow field,forming a complex composite flow field structure.The existence of the rotor,with the wind coming from 0degree direction,markedly enlarges the vortex range and accelerates the downwash flow in the back area of the deck.Crosswinds enlarge the vortex range of the deck and intensify the imbalance of the rotor blades.It becomes unfavorable to the helicopter＇s hovering when the wind comes from 15 degree to the starboard,because the lifting and balance capacity of the rotor blades are the worst under this condition.