Development of Motion-Cancelled PSP System and its Application to a Helicopter Blade

Abstract

We introduce a motion-cancelled pressure-sensitive paint (PSP) system that can be applied to a time-dependent model motion. It consists of a two-color PSP combined with a hi-speed color camera. Our developed PSP has a reference luminescence in green and a pressure-sensitive luminescence in red regions. These are matched with the green and the red images of the camera. By simply rationing the green and the red images, we can cancel the illumination non-uniformity and the change in the camera – PSP distance that causes substantial error for a timedependent PSP measurement. The pressure sensitivity and the temperature dependency are shown to describe the characterizations of the system. An application of this system to a helicopter blade model is included in this paper. The system can capture an unsteady motion of the blade rotation. However, a pressure measurement on the blade is still a challenging. Nomenclature A = coefficient of Stern-Volmer equation B = coefficient of Stern-Volmer equation Cillum = luminescence variation caused by an illumination non-uniformity Cloc = luminescence variation caused by a change in the camera – PSP distance g = function of luminescence variation which is independent of pressures I = luminescent intensity P = static pressure t = time