Pressure Field Measurement on Compressor Cascade Using Pressure-Sensitive Paint

Abstract

In the current work, pressure distribution on the surface of blade and endwall is investigated experimentally in a compressor cascade for capturing some flow features by analyzing pressure profile aerodynamics. Pressure is measured using pressure sensitive paint (PSP) technique. Before the tests, some system errors including temperature-dependence of paint, in-situ calibration, and Self-illumination among neighboring structure are studied in details. In addition, the spatial layout scheme of LEDs and CCDs for each test is designed by self-developing optical theoretical method that based on the LTS (light Tracing Simulation). In the post-processing, an in-situ calibration is conducted to convert the intensity of luminescence to pressure, and each test uses independent calibration equation. Finally, discrete pressure is also measured by pressure taps to compare with PSP. All of the tests are performed at the AOA (Attack of Angle) of −2.5°∼10°, and Mach number of 0.4∼0.8. The results show that the pressure distribution at low Mach number presents a good PSP performance in terms of signal-to-noise-ratio, and apparent pressure step gradient is captured at high Mach number. Meanwhile, the pressure distribution at high incidence reveals the unsteady of separated flow. By combining the end-wall plot with profile plot, the influence of corner-flow on main flow in the passage is obtained.