I. Bolgar, S. Scharnowski, C.J. Kähler

The combination of high-resolution planar PIV with high frequency dynamic pressure transducers allows for the correlation of velocity field fluctuations with wall pressure fluctuations. This technique was successfully applied at the TWM facility in order to resolve the driving flow mechanisms that create the dynamic pressure loads aft of a BFS. Experiments at Ma[infinity] = 0.8 were conducted, while PIV and pressure data were recorded simultaneously over 33s at 15 Hz and 25 kHz, respectively. By offsetting the pressure data, which is correlated with the PIV images by a few samples, it is possible to statistically track the dominant flow phenomenon in space and time, thus artificially increasing the temporal resolution of PIV. This allows for the determination of important fluid mechanic properties such as the convection velocity of the dominant fluid motion, as well as the vortex shedding frequency. The results show that the most dominant phenomenon exciting the dynamic loads aft of a BFS are the Kelvin-Helmholtz vortices in the reattaching shear layer, occuring at a Strouhal number normalized to the step height of Srh = 0.13.

Deutscher Luft- und Raumfahrtkongress 2017, München

Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn, 2017

Conference Paper

englisch

21,0 x 29,7 cm, 10 Seiten

urn:nbn:de:101:1-2017092216889

Heckströmung von Trägerraketen, TR40

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22.09.2017