基于RANS方程的共轴刚性旋翼气动干扰参数影响分析  

Influence Analysis of Coaxial Rigid Rotors Aerodynamic Interference based on RANS Equation

作　　者：田波 李春华[1] TIAN Bo;LI Chunhua(China Helicopter Research and Development Institute,Jingdezhen 333001,China)

机构地区：[1]中国直升机设计研究所,江西景德镇333001

出　　处：《直升机技术》2021年第2期1-7,15,共8页Helicopter Technique

摘　　要：基于雷诺平均Navier-Stokes(RANS)方程建立了适用于共轴刚性旋翼悬停和前飞流场计算的数值模拟方法,采用运动嵌套网格技术计入旋翼复杂运动,通过对试验模型的计算对比验证了方法的准确性。采用共轴刚性旋翼配平作为计算输入,对旋翼气动干扰特性进行计算分析,并研究了旋翼间距、相遇方位角对气动干扰特性的影响。结果表明:共轴刚性旋翼流场存在强烈的桨涡干扰现象,上下旋翼相遇过程会发生“载荷效应”和“厚度效应”,造成拉力周期性波动;随前飞速度增加,旋翼间非定常效应减弱,旋翼升阻比先增大后减小,共轴刚性旋翼升力偏置量增大;小的旋翼间距会加剧双旋翼间气动干扰,随间距增大,上旋翼拉力和悬停效率增加,下旋翼无明显变化;旋翼中高速度前飞流场中相遇角22.5°较0°相遇角拉力幅值降低,拉力波动1/2峰峰值降低一半,拉力的4Ω幅值明显降低,旋翼拉力波动周期从4/Rev变为8/Rev。A numerical simulation method suitable for the calculation of the flow field of the coaxial rigid rotor hovering and forward flight was established based on the Reynolds average Navier-Stokes(RANS)equation.The complex motion of the rotor was accounted for by the moving overset grid technology.The accuracy of the method was verified by the calculation of the experimental model.Trimmed the coaxial rigid rotors as the calculation input.The unsteady aerodynamic characteristics of the coaxial rigid rotors were calculated and analyzed,and the aerodynamic interference persistence of the rotor spacing and encounter azimuth angle was studied.The results showed that there was a strong vortex interference phenomenon in the flow field of the coaxial rigid rotor.The"load effect"and"thickness effect"would occur during the encounter of the rotors,causing periodic fluctuations in the pulling force;as the forward flight speed increases,the unsteady effect between the rotors weakened,the lift-to-drag ratio of the rotor first increased and then decreased,and the lift offset increased;small rotor spacing would increase the aerodynamic interference between the two rotors.As the distance increased,the upper rotor tension and hovering efficiency increased,and the lower rotor did not change significantly;in the flow field of high speed forward flight,the tension amplitude of cross angle 22.5°was lower than of 0°cross angle,the 1/2 peak-to-peak value decreased by one half.The 4Ωamplitude of the trust was significantly reduced,and the cycle of the rotor tension fluctuation changed from 4/Rev to 8/Rev.

关 键 词：共轴刚性旋翼 气动干扰 旋翼配平 RANS方程 运动嵌套网格 相遇角 

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]