An experimental study of the time-dependent behavior of the appendage-body junction vortex
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An experimental study of the time-dependent behavior of the appendage-body junction vortex by Joseph M. Fallone

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Published by Available from the National Technical Information Service in Springfield, Va .
Written in English


Book details:

The Physical Object
Pagination97 leaves.
Number of Pages97
ID Numbers
Open LibraryOL25494855M

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  Recent studies in wind tunnels have identified a bi-modal characteristic in the structure of the vortex. An experimental investigation of the time dependent behavior of the junction root vortex was conducted using MIT's variable pressure water tunnel and laser doppler anemometry : Joseph F. Fallone. An experimental study of the time-dependent behavior of the appendage-body junction vortex. By Joseph M. Fallone Download PDF (6 MB)Author: Joseph M. Fallone. Devenport W J and Simpson R L, a, t'Time- dependent and time-averaged turbulence structure near the nose of an wing-body junction", Journal of Fluid Mechanics, vol. , pp Devenport W J and Simpson R L, b, "An experimental investigation of the flow past an idealized wing-body junction: preliminary data report", AOE Dept., VPI&SU. The horseshoe vortex generated around the appendage–body junction of submarines strongly influences the non-uniformity of submarine wakes at the propeller discs.

The time-dependent and time-averaged features of a wing-body junction flow formed around a cylindrical wing with a elliptical nose and NACA tail are being studied. In this paper, velocity and skin friction measurements made in the nose region are presented and discussed. The time-averaged kinematical and dynamical characteristics of the junction vortex system in front of a symmetrical obstacle are systematically analyzed for both laminar and turbulent flows. A wide set of experimental and numerical results from the literature is coordinated in nondimensional form together with some new computational data. The low frequency, large scale bimodal behavior of the horseshoe vortex at the nose of the junction is characterized by multiple frequencies within f.δ/U∞=[−] (where δ is the boundary.   Junction flows may suffer from secondary flows such as horseshoe vortices and corner separations that can dramatically impair the performances of aircrafts. The present article brings into focus the unsteady aspects of the flow at the intersection of a wing and a flat plate. The simplified junction flow test case is designed according to a literature review to favor the onset of a corner.

  The past experimental and numerical studies[1] of junction flows were extensively reviewed and their underlying physics were discussed. The most striking finding of previous experiments was that the horseshoe vortex was dominated by coherent, low-frequency un- steadiness and characterized by bimodal histograms of probability density functions. The effectiveness of passive flow-control devices in eliminating high surface rms pressure fluctuations at the junction of several idealized wing/body junction flows was studied. Wall-pressure fluctuation measurements were made using microphones along the line of symmetry at the wing/body junction of six different wing shapes. We study numerically the appearance and number of axial vortices in the outlets of X-shaped junctions of two perpendicular channels of rectangular sections with facing inlets. We explore the effect.   The experimental results show that the heat transfer is reduced in the junction region and the level of heat reduction is greatly dependent on the size of the vortex generators. Moreover, the lateral gap between the vortex generators has an influence on the peak value of the heat transfer as well as on the local variation of the heat transfer.