A Phenomenological Model for the Momentumless Turbulent Wake in a Stratified Medium
A Phenomenological Model for the Momentumless Turbulent Wake in a Stratified Medium

Author: D. R. S. Ko

Publisher:

Published: 1973

Total Pages: 53

ISBN-13:

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The growth and collapse of the turbulent wake behind a submarine in a stratified ocean is studied analytically using simple phenomenological models. The present analysis closely follows a previous integral approach based on the concept of local similarity and turbulent entrainment. A nonuniform entrainment rate, obtained by considering the three turbulent velocity components separately, marks the main difference to the previous approach. The present analysis is limited to a wake without swirl and does not include the energy leakage through the internal wave field.

Journal of Hydronautics
Journal of Hydronautics

Author:

Publisher:

Published: 1980

Total Pages: 260

ISBN-13:

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A publication of the American Institute of Aeronautics and Astronautics devoted to marine science and technology.

Turbulent Wakes in a Stratified Fluid. Part 1: Model Development, Verification, and Sensitivity to Initial Conditions
Turbulent Wakes in a Stratified Fluid. Part 1: Model Development, Verification, and Sensitivity to Initial Conditions

Author: W. S. Lewellen

Publisher:

Published: 1974

Total Pages: 134

ISBN-13:

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A computational model has been developed for the turbulent wake of a body moving through a stably stratified fluid. Details of the wake growth, collapse and generation of internal waves were examined by the application of a second-order closure approach to turbulent flow developed at A.R.A.P. over the past few years. Predictions of the model have been verified by comparison with a wide variety of wake flows including wakes with no momentum, wakes with axial momentum, wakes with angular momentum, and for wakes in both stratified and unstratified fluids. A sensitivity investigation reveals that the primary variable affecting the strength of the generated internal waves is the initial Richardson number, with the first local maximum of the vertical height of the wake scaling inversely with the 1/8th power of the initial Richardson number.

Experiments on Turbulent Wakes in a Stable Density-stratified Environment
Experiments on Turbulent Wakes in a Stable Density-stratified Environment

Author: Walter P. M. van de Watering

Publisher:

Published: 1969

Total Pages: 74

ISBN-13:

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In a laboratory experiment, turbulent mixed regions were generated in a linearly density-stratified fluid and their behavior was studied. Such regions may occur in nature in the atmosphere and in the ocean. Particularly during their early history, the shape of such regions is influenced by the interacting effects of turbulence and buoyancy, culminating in the occurrence of a maximum thickness and subsequent vertical collapse. A Richardson number (equivalent to the ratio of the characteristic turbulence time and the Vaisala period) was found satisfactorily to correlate the data obtained, together with those previously obtained by other investigators with self-propelled bodies. An estimate is made of the degree of mixing that takes place inside a turbulent mixed region during its growth in stably-stratified surroundings: the effectiveness of this mixing determines the ultimate thickness to which the mixing region collapses. (Author).