共轴式双旋翼悬停流场和气动力的CFD计算

考虑到共轴式双旋翼流场特征高度复杂、桨叶承受非定常气动载荷的特点,为更好地预测共轴式双旋翼的气动特性,把非结构嵌套网格方法和网格的自适应技术相结合,发展了一套适合于共轴式双旋翼流场数值计算的求解器.在该求解器中,采用非结构嵌套网格方案来模拟桨叶之间存在的相对运动,自适应网格技术用来捕捉尾迹对流场和气动特性的影响,求解惯性坐标系下的非定常N-S主控方程来模拟流场的非定常特性.应用该求解器,首先计算了有试验结果可供对比的一副试验旋翼的诱导速度场分布,在此基础上,计算了共轴式双旋翼的桨尖涡轨迹和拉力分布特性,并与单旋翼的计算结果进行了对比和分析,得到了一些有意义的结论.

Calculation on flow field and aerodynamic force of coaxial rotors in hover with CFD method

A solver which is suitable for the calculation of the coaxial rotor flow field was developed after considering the complexity of flowfield and the unsteady aerodynamics of blades by combining the unstructured embedded grid method and the adaptive technique,aiming at estimating the characteristics of coaxial rotor flowfield with more accuracy.In this solver,the unstructured embedded grid method was adopted to simulate the relative movement among the blades,the adaptive technique was taken into account to capture the wake and its effects to the flowfield and aerodynamics,and the unsteady N-S equations were solved to simulate the unsteady characteristics of coaxial rotor flowfield.Based on this solver,the induced velocity field of a coaxial rotor with experimental data was simulated,then the tip-vortex trajectory and thrust distribution were calculated and compared with the corresponding single rotor results,and some meaningful conclusions were drawn.