The results of different approaches to quantitative flow visualization with large-scale capability are presented. The techniques were applied on the occasion of a measurement campaign in a medium-sized subsonic wind tunnel that addressed a passive wake control problem on an excursion boat. The obtained data was compared qualitatively with numerical results. Fluorescent tufts attached to the surfaceLandolt, A. in the area of interest were filmed by a digital camera. Subsequent post-processing retrievedBorer, D. the local intensity variance and thus the tuft’s movement. This allowed for both, the identification of local flowMeier, A. direction and regions of detached flowRoesgen, T. on the surface of the model. Helium-filled soap bubbles were tracked using an asynchronous temporal contrast sensor or Dynamic Vision Sensor (DVS). The sensor is recording temporal changes in intensity only and has a high dynamic range which made it possible to track the bubbles in ambient light conditions. The recordings yielded local flow velocity and the streamlines around the model. The pressure field or local flow direction were recorded by tracking hand-held probes in 3D space with a stereo vision system. The system allowed free placement and fast measurements close to the model’s complex surface or in its wake. By moving the probe in the volume of interest and with suitable post-processing applied, a quick quantitative assessment of the pressure field and flow topology was possible. The application of the different techniques confirmed the potential of quantitative flow visualization in large-scale testing. The methods complemented each other in the sense that they served to extract surface flow, streamlines and pressure fields.
Quantitative Flow Visualization Applied to a Passive Wake Control Problem
Lect.Notes in Applied (formerly:Lect.Notes Appl.Mechan.)
International Conference on Engineering Conferences International ; 2010 ; Potsdam, Germany September 12, 2010 - September 17, 2010
2015-08-20
13 pages
Aufsatz/Kapitel (Buch)
Elektronische Ressource
Englisch
Supersonic wake flow visualization
AIAA | 1969
|Supersonic wake flow visualization
AIAA | 1969
|NTIS | 2001
|Inexpensive quantitative flow visualization
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