摘要:AbstractSensitivity analysis and uncertainty quantification are computationally expensive procedures. Stochastic expansion methods are an alternative approach for performing SA and UQ, and usually require fewer function evaluations. Recent work has extended non-intrusive stochastic expansion methods for calculating sensitivity indices. We examine the application of these techniques to a case in which data are generated from coupled, nonlinear partial differential equations. The values we analyze are generated from the numerical solution of the PDEs, in which we systematically vary both (i) fundamental modeling parameters and (ii) the underlying numerical algorithms. Our goal is to compare the performance of the sensitivity index calculations using sampling based methods and stochastic expansion methods, to gain an understanding of the strengths and weaknesses of both approaches.