Uncertainty Quantification of k-ω Turbulence Model for Hypersonic Flow

The formulation of turbulence models contains a considerable source of uncertainty. The goal of this work is to investigate the uncertainty and sensitivity of k-omega model due to uncertainty in the values of closure coefficients. Specifically, uncertainty analysis is performed for hypersonic flow over an all-body aircraft. In the current study, firstly a stochastic expansion based on point collocation Non-Intrusive Polynomial Chaos (NIPC) expansion is utilized to identify the uncertainties. Then Sobol indices are used to rank the relative contribution of each closure coefficient. The sensitivity analysis showed that (sigma) contributes most in hypersonic flow both in heat flux and pressure in most areas, while near the expansion shock beta* becomes the top contributor for uncertainty of pressure.