Masters Theses

Keywords and Phrases

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Abstract

"The goal of this work was to quantify the uncertainty and sensitivity of commonly used turbulence models in Reynolds-Averaged Navier-Stokes codes due to uncertainty in the values of closure coefficients for transonic, wall-bounded flows and to rank the contribution of each coefficient to uncertainty in various output flow quantities of interest. Specifically, uncertainty quantification of turbulence model closure coefficients was performed for transonic flow over an axisymmetric bump at zero degrees angle of attack and the RAE 2822 transonic airfoil at a lift coefficient of 0.744. Three turbulence models were considered: the Spalart-Allmaras Model, Wilcox (2006) k-ω Model, and the Menter Shear-Stress Transport Model. The FUN3D code developed by NASA Langley Research Center and the BCFD code developed by The Boeing Company were used as the flow solvers. The uncertainty quantification analysis employed stochastic expansions based on non-intrusive polynomial chaos as an efficient means of uncertainty propagation. Several integrated and point-quantities are considered as uncertain outputs for both CFD problems. All closure coefficients were treated as epistemic uncertain variables represented with intervals. Sobol indices were used to rank the relative contributions of each closure coefficient to the total uncertainty in the output quantities of interest. Two studies were performed in this work. The main study identified a number of closure coefficients for each turbulence model for which more information will reduce the amount of uncertainty in the output significantly for transonic, wall-bounded flows. A case study demonstrated that the RAE 2822 sensitivity results of the main study are independent of the flow solver and of the computational grid topology and resolution"--Abstract, page iii.

Advisor(s)

Hosder, Serhat

Committee Member(s)

Riggins, David W.
Isaac, Kakkattukuzhy M.

Department(s)

Mechanical and Aerospace Engineering

Degree Name

M.S. in Aerospace Engineering

Sponsor(s)

United States. National Aeronautics and Space Administration

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2015

Pagination

xii, 92 pages

Note about bibliography

Includes bibliographic references (pages 89-91).

Rights

© 2015 John Anthony Schaefer, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Library of Congress Subject Headings

Turbulence -- Computer simulation
Turbulence -- Mathematical models
Fluid dynamics -- Approximation methods
Turbulent boundary layer -- Mathematical models
Uncertainty -- Mathematical models

Thesis Number

T 10800

Electronic OCLC #

936209445

Comments

Funding support was provided by the Missouri S&T MAE Department, the Missouri S&T Chancellor's Fellowship Program, and NASA Grant NNX14AN17A (technical monitor: Mujeeb Malik).

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