LED or LASER based lifetime PSP measurements

Abstract

Two different measurement techniques are compared in an application of pressure-sensitive paint (PSP) in a wind tunnel test at the transonic wind tunnel Göttingen (DNW-TWG). Besides the standard lifetime method with accumulation of many single exposures on a CCD camera by using LEDs as light sources, a single-shot technique using a modified CCD camera and a laser for excitation of the PSP was applied to measurements on the DLR Fl 7 model. The results of both techniques are in good agreement. While the standard Lifetime technique delivers better signal-to-noise ratio for a larger observable surface, the singleshot technique shows also potential for applications with fast rotating objects.