低密度环境旋翼三维流动特性的PSP与Stereo-PIV实验研究

工作在低密度环境中的旋翼无人机是火星等地外星球探索的重要工具。与常规旋翼相比，低密度环境中旋翼的流场具有低雷诺数与高马赫数的显著特征，尤其是流动参数沿径向的变化会造成复杂的三维分离流动。本项目拟利用PSP及Stereo-PIV技术对低密度环境中旋翼的三维流动特性开展研究：首先，研究PSP在低密度环境下的压力响应机理，解决当前PSP压力敏感性不足、发光寿命长的问题；随后，在真空试验舱中开展旋翼实验（环境压力1至20kPa），理清桨叶表面压力分布与三维流动结构的相互作用机制。在低转速（不可压）与高转速（可压）条件下，分别研究雷诺数与马赫数对于旋翼桨叶压力载荷与分离流动的影响。本项目能够突破传统测量技术的瓶颈，揭示低密度环境中旋翼复杂的流动机理，为我国高性能火星旋翼无人机的开发奠定基础。

Rotorcraft working in low-density environment is an important tool for exploring Mars and other extraterrestrial planets. Compared with conventional rotors, the flow field of rotor in low-density environment has the characteristics of low Reynolds number and high Mach number. Especially, the change of flow parameters along the radial direction will lead to complex three-dimensional separation. This project intends to study the three-dimensional flow characteristics of rotor in low-density environment by using PSP and stereo PIV. Firstly, the pressure response mechanism of PSP in low-density environment is studied to solve the problems of insufficient pressure sensitivity and long luminescent life of PSP. Then, the rotor experiments are conducted in a vacuum chamber (ambient pressure 1-20kpa) to clarify the interaction mechanism between surface pressure distribution and three-dimensional flow field. The effects of Reynolds number and Mach number on the pressure distribution and separated flow field on rotor blade are studied at low (incompressible) and high (compressible) rotational speeds, respectively. This project can break through the bottleneck of traditional measurement technologies to reveal the complex flow mechanism of rotor in low-density environment, and lay the foundation for the development of high-performance Mars rotor UAV in China.