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Formation and near-field dynamics of a wing tip vortex

Citation

Zuhal, Lavi Rizki (2001) Formation and near-field dynamics of a wing tip vortex. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechTHESIS:02072013-122723580

Abstract

The search for a more efficient method to destroy aircraft trailing vortices requires a good understanding of the early development of the vortices. For that purpose, an experimental investigation has been conducted to study the formation and near-field dynamics of a wing tip vortex.

Two versions of the Digital Particle Image Velocimetry (DPIV) technique were used in the studies. Planar DPIV was used to obtain velocity fields adjacent to the wing surface. Stereoscopic DPIV, which allows instantaneous measurements of all three components of velocity within a planar slice, was used to measure velocity fields behind the wing. The trailing vortex was produced by a rectangular half-wing model with an NACA 0012 profile. All measurements were made at Reynolds number, based on chord length, of 9040.

The present study has found that the wing sheds multiple vortices. A structure that closely resembles a wing tip vortex is first observed on the suction side of the wing near the tip at the mid-chord section of the wing. At the trailing edge of the wing, a smaller vortex with an opposite sense of rotation is observed next to the tip vortex. In addition to the two vortices, two vortex layers with opposite sense of rotation, one on the pressure side and one on the suction side, are apparent at the trailing edge. Farther downstream, most of the vorticity in the vortex layer, with the same sense of rotation as the tip vortex, rolls up into the wing tip vortex. The vortices, with opposite sense of rotation, break up into smaller vortices which orbit around the tip vortex. At least one relatively strong satellite vortex appears in some of the instantaneous fields. The studies found that the interaction of the tip vortex and satellite vortices give rise to the unsteady motion of the wing tip vortex. In addition, the studies also examined the effects of the boundary layer and the tip geometry to the strength and motion of the trailing vortex.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Aeronautics
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Aeronautics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Gharib, Morteza
Thesis Committee:
  • Hornung, Hans G.
  • Leonard, Anthony
  • Shepherd, Joseph E.
  • Colonius, Timothy E.
Defense Date:20 April 2001
Record Number:CaltechTHESIS:02072013-122723580
Persistent URL:http://resolver.caltech.edu/CaltechTHESIS:02072013-122723580
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:7469
Collection:CaltechTHESIS
Deposited By: Benjamin Perez
Deposited On:08 Feb 2013 17:31
Last Modified:28 Jul 2014 19:01

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