A New Plasma Pressure Measurement Technology Based On Dielectric Barrier Discharge

With the rapid development of aerodynamics, the flow filed structures of aircraft and turbomachinery are increasingly complex, which places higher and more stringent demands for unsteady flow field measurement techniques. Surface pressure measurement technology has significant meaning to the forecast of blade flutter, blade design and the capture of rotating stall inception in the aircraft engine. The plasma probe based on gas discharge emerged in the last century. Previous studies showed that the plasma pneumatic measurement technology has advantages of high frequency response, high sensitivity and so on.A plasma pressure display diaphragm (PPDD) was devised based on the principle of dielectric barrier discharge (DBD) and the author tried to apply it to measure the surface pressure in this paper. The author built a plasma laboratory, designed several diaphragms of different structures and provided verification of the principle of PPDD with experimental results. Then a static calibration system and a dynamic calibration platform were built. Effects of different factors on the performance of PPDD were explored and dynamic response characteristics of the diaphragm were tested. The contents in this dissertation can be briefly summarized as below:1. The measuring principle of the diaphragms was introduced. The brightness of DBD plasma changes with gas pressure. Then theoretical basis and experimental verification were provided for the principle. Specific research plan based on the measurement principle was put forward and the author presented preliminary data processing method.2. Different design schemes of PPDD were explored.3. A static calibration platform is built. Impacts of various factors on the performance of PPDD were studied through experiments in the static calibration system and the measurement errors were analyzed. This work could be used to provide guidance to improve and optimize the diaphragm.4. A qualitative measurement of the surface pressure on a flat panel was carried out in a low-speed wind tunnel. The measurement results of PPDD and the exact results from pressure scanning valve were compared and analyzed.5. A rotary jet disk was used in the experiments to test the dynamic response characteristics of the diaphragm. Photomultiplier tube was used for the brightness acquisition of PPDD and fast fourier transformation (FFT) analysis was applied to prove that its frequency response could reach 1980Hz. Then the research plan in which the shock tube was employed for further testing of the dynamic response of PPDD was proposed.In the last part of the article, the key technologies of PPDD were forecasted.