Seminar Details:

LANS Informal Seminar
"Multi-Resolution-Analysis Scheme for Uncertainty Quantification in Chemical Systems"

DATE: January 17, 2008

TIME: -
SPEAKER: Philippe Pebay, Sandia National Laboratories
LOCATION: Building 221, Room C-101, Argonne National Laboratory

Description:
This talk with present a multi-resolution approach for the propagation of parametric uncertainty in chemical systems. This work is motivated by previous studies where Galerkin formulations of Wiener-Hermite expansions were found to fail in presence of steep dependences of the species concentrations with regard to the reaction rates. The multi-resolution scheme is based on representation of the uncertain concentration in terms of compact polynomial multi-wavelets, allowing for the control of the convergence in terms of polynomial order and resolution level. The resulting representation is shown to greatly improve the robustness of the Galerkin procedure in presence of steep dependences. However, this improvement comes with a higher computational cost which drastically increases with the number of uncertain reaction rates. To overcome this drawback an adaptive strategy is proposed to control locally (in the parameter space) and in time the resolution level. The efficiency of the method is demonstrated for an uncertain chemical system having eight random parameters.

This work was supported by the Laboratory Directed Research and Development Program at Sandia National Laboratories, funded by the US Department of Energy. Support was also provided by the Defense Advanced Research Projects Agency (DARPA) and Air Force Research Laboratory, Air Force Materiel Command, USAF, under agreement number F30602-00-2-0612.


 

Please send questions or suggestions to Debojyoti Ghosh: ghosh at mcs dot anl dot gov.