Transition detection methods in a pitch-sweep test by means of tsp using lifetime and intensity measurements

A combination of carbon nanotube and Temperature Sensitive Paint (cntTSP) has a potential to visualize dynamic movement of the boundary-layer transition on a model surface. One wide area of application for the use of cntTSP is the continuous model pitch-sweep tests, which are desired in order to improve the data productivity of the wind tunnel. In this paper, the applicability of cntTSP to a continuous moving model (pitch-sweep test) is investigated in a low-speed wind tunnel with a simplified airplane model wing. Two TSP measurement methods, the intensity and single-shot lifetime method, and two data reduction methods for the transition detection, the maximum temperature slope method and the differential thermography methods, were examined. All methods performed in this work successfully detected the moving boundary-layer transition on the pitch-sweep model and results matched well. The advantages and technical difficulties of each method are also discussed.