The invention provides a low-torque supercritical natural laminar flow airfoil for the middle of a high-speed coaxial double-rotor helicopter blade. The radius of the front edge of the airfoil is 0.78%, the maximum thickness of the airfoil is 9.0%, the airfoil is located at the 40.6% chord length position of the airfoil, the maximum camber is 0.69%, the airfoil is located at the 14.0% chord length position of the airfoil, and the included angle of the rear edge is 1.46 degrees. Under the condition that low-speed aerodynamic performance loss is not large, the zero lift torque in the transonic speed state is obviously reduced compared with that of an OA309 airfoil, and the available Mach number range of the airfoil controlled by the torque is obviously increased; the resistance divergence characteristic of the airfoil is also remarkably better than that of an OA309 airfoil, the Mach number reaches 0.844 and is improved by 0.013 compared with that of the OA309 airfoil, and specifically, the airfoil can weaken shock waves on the upper surface of the airfoil in the transonic speed state; and the requirement for resistance coefficient robustness of the outer section airfoil in the rotor of the coaxial double-rotor helicopter is met, and a foundation is laid for airfoil design of the middle part of the blade of the coaxial double-rotor helicopter.
本发明提出一种用于高速共轴双旋翼直升机桨叶中部的低力矩超临界自然层流翼型,翼型前缘半径0.78%,翼型最大厚度为9.0%,位于翼型40.6%弦长处,最大弯度为0.69%,位于翼型14.0%弦长处,后缘夹角为1.46度。本发明在保证低速气动性能损失不大的情况下,跨声速状态的零升力矩比OA309翼型有了明显的下降,使得翼型由力矩控制的可用马赫数范围明显增大;该翼型的阻力发散特性也显著优于OA309翼型,达到了马赫数0.844,比OA309提升了0.013,具体体现在该翼型能够在跨声速状态下削弱翼型上表面激波;且满足共轴双旋翼直升机旋翼中外段翼型阻力系数稳健性要求,为共轴双旋翼直升机桨叶中部的翼型设计奠定了基础。
Low-torque supercritical natural laminar flow airfoil profile for middle part of high-speed coaxial double-rotor helicopter blade
一种用于高速共轴双旋翼直升机桨叶中部的低力矩超临界自然层流翼型
13.10.2023
Patent
Elektronische Ressource
Chinesisch
IPC: | B64C AEROPLANES , Flugzeuge |
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