Interaction of a swirling jet with a free surface
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Authors
Feyedelem, Michael S.
Subjects
Swirling jets
Ship wakes
Free surface
Ship wakes
Free surface
Advisors
Sarpkaya, T.
Date of Issue
1996-03
Date
March 1996
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
The turbulent flow field of a swirling jet issuing from a nozzle, beneath and parallel to a free surface has been studied in as much detail as possible using a three-component laser Doppler velocimeter and flow visualization. The results have shown that the swirl leads to the faster spreading and quicker mixing of the jet. For strongly swirling jets (S = 0.522), the similarity is not reached within ten diameters downstream. The results have also shown that both the acial and tangential velocity components decrease outward from the jet axis, naturall leading to centrifugal instabilities. This, in turn, leads to the creation of large scale coherent structures at the periphery of the jet, particularly when it is in the vicinity of the free surface. The turbulent shear stresses exhibit anisotropic behavior, the largest always being in the plane passing through the jet axis. The change of TKE with S is not monotonic. It is maximum for S - 0.265, smallest for S = 0.50, and has an intermediate value for S - 0.522. This is due to the occurrence of vortex breakdown and the resulting intensification of the turbulence within the jet prior to its exit from the nozzle.
Type
Thesis
Description
Series/Report No
Department
Mechanical Engineering
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funder
Format
175 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.