Pressure sensitive Paints in quantitative Wind Tunnel Studies

Abstract

At 1992 DLR Göttingen started with its own PSP development. The first version, a one direction viewing system, based on a 16bit camera with an 512x512 pixel CCD-element and an UV-light source based on lambda = 337 nm wavelength was optimized for first transonic measurements. Only the important part of PSP - the paint - was ordered that time from OPTROD Company from Russia. Now, since 1998 DLR is independent in paint development, because own paints exist after an intensive cooperation with the Organic-Chemistry Institutes of the Universities of Göttingen and Regensburg. Paints for all speed ranges from low speed to hypersonic Uo = 20m/s up to Ma=6.0 are available. Also an 8-Twin-Camera system was build up to get 360° information, finally to calculate forces and moments from PSP values. A mobile system is developed for different facilities and an own software ToPas for fast data acquisition and presentation of final results; typical time: 2 minutes later, after an obtained polar with 12 different angles of attack.