基于三维超声风速仪的无人直升机流场测试研究

he flow field of UAV has a great influence on the effect of the spraying operation, but there is a lack of sufficient and accurate dynamic measurement data in the actual measurement of the flow field. This paper builds a system of 3-D flow field measurement, using three-dimensional ultrasonic anemometer for the flow measurement of single rotor helicopter. The flow measurement was carried out with different rotation speed, in different radial distance, and different distance to the plane of the rotor wing. The test results show that, the absolute wind speed and vertical wind speed increases with the increase of rotation speed in general. The absolute wind speed and vertical wind speed take the same changing characteristic with the variation of different height and different radial position. At different heights, the maximum absolute wind velocity appears in different radial positions. At the height of 37.0cm, the maximum absolute velocity is maximum at at 60.2cm radial distance. Compared with the vertical velocity, the amplitude of the horizontal direction is smaller and the changing characteristics of the horizontal velocity is different. The horizontal velocity is not consistent with the rotational speed, but the direction of the horizontal velocity is roughly along tangent direction of the rotor.