旋翼涡尾流与下洗流场的计算方法

 以重点考察旋翼尖涡的运动为目标来构想一种悬停和前飞旋翼涡尾流的理论计算方法.首先从预定的广义尾流入手,并引入尖涡涡核作用的半经验修正,对旋翼的自由尾流进行计算分析.然后在环量收敛与尾迹收敛的条件下,计算拉力以满足拉力收敛准则.之后,作为本方法的工程应用,文中给出了计算的旋翼沿火箭发射线的下洗速度分布并作了简单分析.从理论上说,文中所发展的方法可以为进一步研究尖涡的生成模式与涡核结构所应用,同样也可以预测旋翼的涡诱导流场.

旋翼涡尾流与下洗流场的计算方法

An analytical method for predicting rotor vortex wake in low speed and hovering flight is described to investigate the motion of the helical tip vortex. Beginning with the prescribed wake model, a Semi Empirical Correction for the vortex core effect on rotor wake is made and free wake calculation is carried out. Then on the condition of circulation and wake geometry convergence, the rotor thrust is calculated to satisfy convergence criterion of thrust. Finally, as an example of its engineering application, the calculated downwash velocity field along the rocket launch line is presented and simply analysed. In terms of theory, the calculating method developed here may provide referable basis for further studying the formation mode of the tip vortex and vortex core interior structure. Also the method is practical for predicting rotor induced flow field in engineering applications.