旋翼近水面悬停状态气动特性分析  

Analysis of aerodynamic characteristics of rotor near water surface

作　　者：杨帆 赵国庆[1] 陈希[1] 招启军[1] 曹宸恺 YANG Fan;ZHAO Guoqing;CHEN Xi;ZHAO Qijun;CAO Chenkai(National Key Laboratory of Rotorcraft Aeromechanics,NUAA,Nanjing 210016,China)

机构地区：[1]南京航空航天大学直升机旋翼动力学国家级重点实验室,江苏南京210016

出　　处：《飞行力学》2023年第3期1-6,共6页Flight Dynamics

基　　金：国家自然科学基金资助(12072156);重点实验室基金资助(61422202103);江苏高校优势学科建设工程资助项目。

摘　　要：针对直升机在近水面区域飞行时的旋翼气动特性问题,基于RANS方程,结合流体体积(VOF)方法开展了旋翼水面效应流场的模拟分析研究。为提高水/气交界面的旋翼桨尖涡的捕捉精度,在背景网格区域采用了自适应网格方法,并通过与Caradonna-Tung旋翼试验结果的对比,验证了所提方法的可靠性。随后,基于该方法模拟了旋翼在地面、静水面、小幅波浪水面和大幅波浪水面4种工况下的地面/水面效应流场,对不同状态下的旋翼气动特性及水面干扰机理进行了细致讨论。结果表明:地面效应及水面效应下,旋翼桨尖涡更早向外扩散且桨叶中段的表面压强增幅比桨尖处更大,水面效应的强度要弱于地面效应;而波幅更高的波浪所引发的附着涡更容易改变桨尖涡的发展轨迹,增加桨尖涡的不对称性。In order to analyze the aerodynamic characteristics of the rotor when the helicopter is flying near the water surface,the simulation analysis of the rotor waveground effect flow field is carried out based on the RANS equation and combined with the VOF method.In order to improve the capture accuracy of the rotor tip vortex at the water-air interface,an adaptive mesh refinement method is adopted in the background grid area.The effectiveness of the method is verified by comparing with the Caradonna-Tung rotor test results.Then,based on this method,the ground/waveground effect flow field of the rotor under four conditions of ground,still water,small wave water surface and large wave water surface is simulated,and the aerodynamic characteristics and water surface interference mechanism of the rotor under different conditions are discussed in detail.The results show that under the ground and waveground effects,the rotor tip vortex diffuses earlier and the surface pressure increase in the middle of the blade is larger than that at the tip.Among them,the waveground effect is weaker than the ground effect,and the attached vortex induced by waves is more likely to change the development trajectory of the tip vortex when the wave amplitude is larger,which increases the asymmetry of the tip vortex.

关 键 词：旋翼 桨尖涡 VOF方法 地面效应 水面效应 

分 类 号：V211.52[航空宇航科学与技术—航空宇航推进理论与工程]