Doctoral Dissertations

Abstract

"A general method is presented for analyzing turbulent flow fields in the near wake regions of two-dimensional and axisymmetric bodies. The governing partial differential equations of continuity, momentum and turbulence kinetic energy are expressed in elliptic form in terms of the dependent variables stream function, vorticity and turbulence kinetic energy. An iterative finite-difference technique is used to solve the governing equations simultaneously. Numerical solutions are obtained for the following physical problems: 1. Laminar near wake: Only stream function and vorticity are considered for laminar flow. Solutions are compared with available analytical results for uniform flow over a sphere. 2. Turbulent near wake: Predicted distributions of stream function, vorticity, mean velocity, mean static pressure and turbulence kinetic energy are obtained for two-dimensional and axisymmetric turbulent wakes. Comparisons are made with experimental data for the two-dimensional turbulent wake of a wedge and for the axisymmetric turbulent wake of a spheroid. Solutions are obtained by two methods. The first method uses experimental data to determine effective viscosity distributions. Simultaneous solutions for stream function and vorticity are obtained in terms of the known effective viscosity, and the turbulence kinetic energy equation is solved as an auxiliary equation. Empirical models are developed to describe various terms in the turbulence kinetic energy equation. The second method assumes that initial distributions of effective viscosity are not available. The turbulence kinetic energy equation is solved simultaneously with the equations for stream function and vorticity. An additional empirical model is developed to close the system of equations. Both methods are used to construct energy balances for turbulence kinetic energy. Comparisons are made with far wake experimental energy balances. The primary advantage of the turbulence kinetic energy approach is its ability to consider the "history" of turbulence in a given flow field. A systematic development of this approach with the assistance of detailed turbulence measurements offers the promise of eventually leading to more realistic solutions of free turbulent mixing problems for engineering applications"--Abstract, pages ii-iii.

Advisor(s)

Lee, S. C.

Committee Member(s)

Oetting, R. B.
Rhea, L. G.
Howell, Ronald H. (Ronald Hunter), 1935-
Ho, C. Y. (Chung You), 1933-1988

Department(s)

Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering

Sponsor(s)

United States. Department of Defense
National Center for Atmospheric Research (U.S.)

Publisher

University of Missouri--Rolla

Publication Date

1971

Pagination

xiii, 105 pages

Note about bibliography

Includes bibliographical references (pages 98-104).

Rights

© 1971 James Edward Auiler, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Subject Headings

Turbulence -- Mathematical models
Turbulent boundary layer
Wakes (Fluid dynamics)
Kinetic theory of matter

Thesis Number

T 2616

Print OCLC #

6038567

Electronic OCLC #

874572465

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