SC²S Colloquium - June 01, 2016

Date:	June 1, 2016
Room:	02.07.023
Time:	3:00 pm, s.t.

Alexander Rusch: Extending SU2 to fluid-structure interaction via preCICE

TBA

Jan Sültemeyer: Uncertainty Quantification in Fluid Flows via Polynomial Chaos Methodologies

The focus of this thesis lies on the comparison of different methodologies for uncer- tainty quantification in computational fluid dynamics. Two methods based on poly- nomial chaos expansions – namely the pseudo spectral approach and the stochastic Galerkin method – are introduced and employed for modeling the forward propaga- tion of uncertainty. A simulation based on Monte Carlo sampling is performed for the purpose of validation. The chosen flow scenario is a two dimensional lid driven cavity, simulated by solving the Navier Stokes equations via a finite difference scheme. The viscosity of the fluid is assumed to be uncertain, and it is modeled as a random variable with a Gaussian probability distribution. The influence of this uncertainty on the pressure and the velocity of the fluid at different points in the domain is studied. Their statistical properties – i.e. the mean value and the variance – are computed, and their probability density functions are estimated following a kernel density approach. Both methodologies are used for these computations and are then compared with respect to their convergence behavior, their computational cost, and the effort needed for their implementation.