贴地飞行的旋翼尾迹研究

本文研究了贴地飞行的重要气动问题—地面涡现象。通过对旋翼近地尾迹的分析,建立了计算地面涡的离地高度、纵向位置和强度的计算模型、公式和方法,并以此计算了桨盘处诱导速度分布。计算结果与实验值作了比较,达到了相当好的一致性。

A STUDY OF THE ROTOR WAKE IN NAP-OF-THE-EARTH

In this paper an investigation of the ground vortex, the significant aerodynamic phenomenon in rotor aerodynamics on nap-of-the earth, is carried out. Based on the analysis of the rotor wake near the ground, a theoretical method, including the analytical model, the formulae and the computer program, has been established which can be used for calculationof the ground vortex--the longitudind position, the height above theground and its strength. By using a free wake model, with the ground vortex taken into account, the distribution of induced inflow at the r otor disc is also calculated. All computational results are compared with available experimental data and found in good agreement.