Interaction of a vortex pair with a free surface.
Loading...
Authors
Elnitsky, John II.
Subjects
vortex convection
free surface deformation
free surface deformation
Advisors
Sarpkaya, T.
Date of Issue
1987-09
Date
September 1987
Publisher
Language
en_US
Abstract
The trailing vortices generated by the control planes of submarines give rise to surface signatures in the form of scars and striations. Two counter-rotating vortices were generated in a novel experimental system and their interaction with the free surface was investigated. In addition, the governing equations have been solved through the use of the boundary-element method for a representative Froude number. The results have been expressed in terms of the depth of submergence of the vortices, their mutual induction velocity, and the initial vortex separation. It has been shown that the free surface begins to deform when the vortices are at a distance of about one initial vortex separation from the free surface. The height of the maximum deformation is attained at a normalized time of about 0.1, when the vortices are at a distance of about 0.5 bₒ from the free surface. The elevated part of the surface is bounded by two scars, whose motion is slaved to that of the vortices.
Type
Thesis
Description
Series/Report No
Department
Mechanical Engineering
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
112 p.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.