Pressure Measurement on Suction Surface of a Single Vane Using Pressure-sensitive Paint

Global pressure distribution on the suction surface of a single vane in a transonic cascade wind tunnel is measured with the help of intensity-based pressure-sensitive paint (PSP) technique using a type of temperature-insensitive fluorescent paint and a self-made measurement system. This measurement is conducted at the outlet of the cascade wind tunnel at the Mach numbers 0.3 and 0.4, attack angle about -20 degrees, ambient pressure 95.4 kPa and temperature 15 degrees C. The vane under study owns a large camber angle of about 40 degrees and 4x10 pressure ports on its suction surface with a steel cubic stand attached. It is fixed vertically on the lower guide steel plate at the outlet through the stand for convenient acquisition of images. Conventional electronic static pressure (ESP) measurement is also fulfilled simultaneously with an ESP scanner for comparison. The method of intensity-based PSP technique is introduced, especially, with the self-made PSP system. The operating sequence of PSP measurement for improved accuracy is also proposed. The practical steps of image processing are described. As an image registration, target alignment is introduced after the 4x10 pressure ports have been selected as targets. The comparison of PSP results with ESP data shows that the maximum error remains within 6.5%.