Messungen flächiger Druckverteilungen auf Windkanalmodellen mittels Pressure Sensitive Paint (PSP)

Abstract

The pressure sensitive paint (PSP) intensity and lifetime system is an optical measurement technique to investigate absolute pressure fields on model surfaces for basic research in laboratories, industrial wind tunnels or high speed rotating turbo machines. Detailed qualitative and quantitative information and understanding of flow phenomena can be obtained in speed ranges from U? =20 m/s up to Ma= 5.0. A number of investigations of problems of industrial interest in different speed ranges from low speed flow over transonic to trisonic and cryogenic flows have been realised and compared with conventional techniques like pointwise pressure measurements (pressure taps, Kulites®), flow velocity field measurements (PIV), and qualitative visualization (laser light sheets). Influences of the main error sources for the components of the PSP system have been checked. Comparison of experimental pressure fields obtained by means of PSP and the results of numerical calculations have been carried out. Different wind tunnel models ranging from basic configurations such as a cropped delta wing to a complex half model of a large propeller-driven transport aircraft with all flaps, rudders and shrouds, and rotating or oscillating models as well as Reynolds number effects on models have been investigated. Presently two complete mobile PSP systems adapted to different types of industrial applications are available at DLR for accurate planar pressure measurements and for comparison with CFD results.