摘要
直升机着舰流场复杂多变,严重影响着旋翼的气动环境,进而影响直升机着舰安全。本文基于计算流体力学(Computational fluid dynamics,CFD)技术建立了一个直升机动态着舰的数值模拟方法,并以此研究直升机着舰过程中的气动载荷变化。该方法以N-S方程作为控制方程,并选取k-ω湍流模型来提高对涡流场的捕捉精度,采用动量源方法模拟旋翼。应用所建立的方法,着重分析了直升机侧弦进场、垂直降落过程中的耦合流场特征和气动载荷变化。结果表明:直升机侧弦进场时旋翼会与甲板舷涡以及舰船艉部的涡回流区发生较强的涡干扰,导致拉力显著降低,在舰面效应的影响下易产生一个附加的滚转力矩,影响直升机姿态稳定;垂直降落时在上述干扰的综合作用下,旋翼拉力呈现出先减小、后增大的特点,各气动载荷在接近甲板时会出现剧烈的波动,加大了着舰风险。
Ship air wake flow field has complex structures, which seriously affects the aerodynamic environment of rotor and the landing safety of helicopter. This paper proposes the numerical simulation method of helicopter’s dynamic landing based on computational fluid dynamics(CFD),and studies the changes of helicopter’s aerodynamic load in the landing process. The N-S equation is used as the governing equation. The k-ω model is selected as the turbulence model to improve the simulation accuracy of the vortex field and the rotor adopts the momentum source method. Based on the above method,the characteristics of the coupled flow field and the aerodynamic load changes during the helicopter’s landing are analyzed. The results show that when the helicopter enters the field from ship’s one side,the rotor will have strong eddy interference with deck-edge vortices and large recirculation zone,which leads to a significant reduction of thrust. An additional roll moment can be easily produced because of the shipboard effect,which affects the stability of the helicopter. Under the combined effect of the above interference,the rotor thrust is reduced at first and then increases. The aerodynamic load will fluctuate sharply when the helicopter approaches the deck,which will increase the risk of landing for shipboard helicopter.
作者
陈华健
徐国华
史勇杰
CHEN Huajian;XU Guohua;SHI Yongjie(National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics,Nanjing University of Aeronautics&Astronautics,Nanjing,210016,China)
出处
《南京航空航天大学学报》
EI
CAS
CSCD
北大核心
2020年第2期232-239,共8页
Journal of Nanjing University of Aeronautics & Astronautics
基金
江苏高校优势学科建设工程基金资助项目。
关键词
直升机
舰船
动态着舰
艉流场
气动载荷
helicopter
ship
dynamic landing
air wake
aerodynamic load
