倾转旋翼机旋翼对机翼气动干扰的建模及分析

建立了一个耦合旋翼自由尾迹模型和机翼面元模型的悬停状态旋翼/机翼气动干扰迭代计算方法,用于分析旋翼对机翼的气动干扰影响.在该方法中,为较好地模拟大桨盘载荷及大扭转桨叶的气动特征,旋翼桨叶采用Weissinger-L升力面模型;为考虑厚度效应及机翼的升力影响,建立了包含源面元和偶极子面元的厚度机翼模型;为正确模拟旋翼桨尖涡与机翼表面间的贴近干扰,采用了一个"分析数值匹配法"的"贴近涡/面干扰模型".应用上述方法,对单独倾转旋翼下洗流分布以及旋翼对机翼的气动干扰影响进行了计算.结果表明,在旋翼下洗流场的干扰下,机翼各剖面都产生向下载荷,但并非简单地随拉力系数的增大而增大;机翼受到的旋翼干扰影响与旋翼下洗流沿桨叶展向变化密切相关.

Modeling and analytical investigation on rotor/wing aerodynamic interaction for tiltrotor aircraft

Based upon a rotor free-wake model and a 3-D wing panel model,an iterative and full-coupled analytical method for rotor/wing aerodynamic interaction has been developed to predict the interactional effects of the tiltrotor on its wing in hover.In order to simulate the aerodynamic characteristics of the rotor with large disk loading and large twist angles,the rotor blade was modeled by the Weissinger-L lifting-surface theory.A thick wing model combining source panel with doublet panel was adopted for the consideration of both the thickness and lift effects of wings.A close Vortex/Surface Interaction model on the Analytical/Numerical Matching(ANM) was employed in the method for effectively simulating the close interaction between rotor tip-vortex and wing surface.Using the method,the calculations on the downwash flowfield of an isolated titlrotor and the interactional effects of the tiltrotor on wing in hover have been carried out. It is shown that the interaction of the tilt-rotor downwash flowfield will result in the download on each wing section,and the download does not simply follow the variation of the rotor thrust coefficient.The interactional effects of the rotor on wing are closely associated with the spanwise distribution of the rotor downwash.