High-Temperature, Wide-Range, and Fast-Response Thin-Film Anemometer Based on Plasma of Glow Discharge

Obtaining the flow velocity variation of compressor blade surface or wall is of great significance for the fault monitoring and health management of aeroengine. However, the extremely harsh working environment of high temperature, high speed, and high pressure brings severe challenges to the flow velocity measurement. At the same time, the difficulty of blade surface sensor installation also restricts the development of blade surface velocity measurement technology. Plasma sensing technology based on glow discharge can realize the measurement of supersonic Mach number, and it is insensitive to temperature changes and has fast frequency response. Therefore, it can meet the testing requirements of the static and dynamic wall flow field of compressor. In this article, the film sensing technology is combined with plasma wind velocity measurement technology. The design, fabrication, and testing of thin-film plasma anemometer were carried out on alumina insulated base and high-temperature nickel-based alloy blades, respectively, which broke through the difficulty of blade surface sensor installation and verified the feasibility of plasma anemometer technology applied to the measurement of surface flow field on complex curved surfaces. The influence of key parameters of plasma film anemometer on its performance is studied, and the design parameters of the anemometer are optimized. The calibration range of anemometer average speed is 0–150 m/s. In addition, the sensor can withstand temperature up to 700 °C and has a fast response, stable working life of more than 2 h. These results show that the plasma thin-film anemometer has the potential to measure the flow field on blade surface or wall in high-velocity, high-temperature, and high-pressure environment.