压力敏感涂料测量技术在掠型叶栅表面测压中的应用

In order to obtain the pressure distribution on the suction surface of the swept blade，the optical path layout and pressure-sensitive paint（PSP）pressure measurement were carried out for a swept blade cascade with a solidity of 1.53 and a sweep angle of 10.7°. The three-dimensional pressure distribution on the suction surface of the blade，which was easy to extract pressure data and highly readable，was obtained by using image processing and three-dimensional reconstruction algorithms，and was compared with the measurement results of the pressure taps. The results show that the independently developed optical path layout method effectively solved the problems of uneven illumination irradiance on the blade surface，and the limited shooting angle. The original pressure-sensitive images with high signal-to-noise ratio and the pressure distribution on the suction surface of the swept cascade in a wide range of operating conditions were obtained. Compared with the pressure taps，the PSP measurement error was within 5%，and the PSP measurement results also captured the migration of the peak isentropic Mach number position along the chord and the flow separation phenomenon at the trailing edge of the blade. The pressure distribution on the suction surface of the swept blade at different incidence angles and incoming Mach numbers was analyzed. At zero and positive incidence angles，the swept blade has obvious radial pressure gradient，which makes the flow on forward sweep move forward，increases the energy of low energy fluid in the forward swept downflow，and makes forward sweep more helpful to delay corner separation. However，backward sweep is more prone to corner separation. The spanwise pressure symmetry of the swept blade is good at low inlet Mach number，and the influence of the swept design is not significant. The high incoming Mach number magnifies the difference of corner separation control effect between forward and backward sweep. Compared with the limited pressure resolution of traditional pressure taps，PSP measurement can provide abundant and reliable pressure experimental data for the design of swept blades and the analysis of flow mechanism.