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Wing Tip Vortices from an Exergy-Based Perspective
Journal of Aircraft
  • Muhammad Omar Memon, University of Dayton
  • Kevin Wabick, University of Dayton
  • Aaron Altman, University of Dayton
  • Rainer M. Buffo, RWTH Aachen University
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The lens of exergy is used to investigate a wingtip vortex in the near wake over a range of angles of attack. Exergy is the measure of thermodynamically “available” energy as determined through the more discriminating second law of thermodynamics. Experiments were conducted in a water tunnel at Institute of Aerospace Systems at Aachen.

The data were taken three chord lengths downstream in the Trefftz plane of an aspect ratio 5 Clark-Y wing with a square-edged wing tip using particle image velocimetry. Intuitively, the minimum available energy state is expected to correspond to the maximum lift-to-drag ratio angle of attack. This, however, is not the case here. Most interestingly, although only two-dimensional Trefftz plane data were used to obtain the exergy distribution across the individual wing-tip vortices, the crossover point for the out-of-plane change from wakelike to jetlike wing-tip vortex core axial flow (indicating the peak lift-to-drag ratio) is identified by the in-plane exergy distribution. This crossover point is not identifiable in the evaluation of any other characteristics calculated from in-plane quantities. Consequently, the exergy method holds promise as a metric for the improvement of aircraft performance through the reduction of lift-induced drag.

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The author's accepted manuscript is provided for download in compliance with the publisher's policy on self-archiving. There may be some differences between this version and the published version. To read the published version, use the DOI provided or visit an academic library.

This document was previously presented at the 52nd Aerospace Sciences Meeting in National Harbor, Maryland.

Permission documentation is on file.

American Institute of Aeronautics and Astronautics
Peer Reviewed
Citation Information
Muhammad Omar Memon, Kevin Wabick, Aaron Altman and Rainer M. Buffo. "Wing Tip Vortices from an Exergy-Based Perspective" Journal of Aircraft Vol. 52 Iss. 4 (2015)
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