Abstract: A pressure-sensitive paint measurement system is established in a 0.6 m trisonic wind tunnel to resolve the subsystem synchronization control problem. Based on the established pressure-sensitive paint system, this research studies the effect of coating on the surface pressure distribution as well as the image filtering technology and the measurement stability and accuracy of the pressure-sensitive paint system. The system is applied for the first time to the wing surface pressure measurement test in future large passenger aircraft drag reduction and shock control, obtaining the pressure distribution and the shock position of the original wing and the bump wing on the wing upper surface. Then the design of bump is verified to have a good shock control effect in the design state. The results indicate that the changes in surface roughness and thickness caused by low coating quality can significantly affect the pressure distribution, necessitating the need of strict control of the spray quality. In addition, Gaussian filtering with 8-pixel windows and 3-time iterations presents better smoothing of pressure fluctuations without distortion. The pressure coefficient measurement root mean square deviation between the established pressure-sensitive paint system and the pressure sensor is smaller than 0.022,the root mean square deviation of pressure is less than 620 Pa,revealing high measurement accuracy of the pressure-sensitive paint system. Furthermore, the design bump can effectively weaken the shock wave and improve the lift and drag characteristics of the wing in both the design state and non-design state.

Key words: pressure-sensitive paint, quality of coating, image filtering, accuracy, trisonic wind tunnel