"The primary focus of this study is to demonstrate an efficient approach for uncertainty quantification of surface heat flux to the spherical non-ablating heatshield of a generic reentry vehicle due to epistemic and aleatory uncertainties that may exist in various parameters used in the numerical solution of hypersonic, viscous, laminar blunt-body flows with thermo-chemical non-equilibrium. Two main uncertainty sources were treated in the computational fluid dynamics (CFD) simulations: (1) aleatory uncertainty in the freestream velocity and (2) epistemic uncertainty in the recombination efficiency for a partially catalytic wall boundary condition. The Second-Order Probability utilizing a stochastic response surface obtained with Point-Collocation Non-Intrusive Polynomial Chaos was used for the propagation of mixed (aleatory and epistemic) uncertainties. The uncertainty quantication approach was validated on a stochastic model problem with mixed uncertainties for the prediction of stagnation point heat transfer with Fay-Riddell relation, which included the comparison with direct Monte Carlo sampling results. In the stochastic CFD problem, the uncertainty in surface heat transfer was obtained in terms of intervals at different probability levels at various locations including the stagnation point and the shoulder region. The mixed uncertainty results were compared to the results obtained with a purely aleatory uncertainty analysis to show the difference between two uncertainty quantication approaches. A global sensitivity analysis indicated that the velocity has a stronger contribution to the overall uncertainty in the stagnation point heat transfer for the range of input uncertainties considered in this study"--Abstract, page iii.
Riggins, David W.
Mechanical and Aerospace Engineering
M.S. in Aerospace Engineering
United States. National Aeronautics and Space Administration
Missouri University of Science and Technology
x, 95 pages
© 2010 Benjamin Robert Bettis, All rights reserved.
Thesis - Open Access
Computational fluid dynamics
Heat -- Radiation and absorption
Space vehicles -- Atmospheric entry
Print OCLC #
Electronic OCLC #
Link to Catalog Record
Bettis, Benjamin R., "Quantification of uncertainty in aerodynamic heating of a reentry vehicle due to uncertain wall and freestream conditions" (2010). Masters Theses. 4911.