P05: PFLOTRAN: A massively parallel simulator for reactive flows in geologic media Session: Posters: Applications Event Type: Poster Time: 5:00pm - 7:00pm Speaker(s): Richard Tran Mills, Chuan Lu, Peter C. Lichtner Location: 4th Floor South Lobby Abstract: A number of environmental problems of national importance, e.g. geologic sequestration of CO2, require detailed modeling of reactive flows through geologic media. Typical simulations are very computationally demanding, involving 10 or more chemical degrees of freedom on a grid of millions of nodes. We have developed a massively parallel 3-D reservoir simulator, PFLOTRAN, that can model multiphase reactive flows in geologic formations based on continuum scale mass and energy conservation equations. It employs the PETSc toolkit's modular and efficient Newton-Krylov solver framework. This poster will describe PFLOTRAN and will detail its performance on the Cray XT3 (and other architectures). We will discuss the influence of the XT3 architecture on our choice of algorithms. Furthermore, we will present insights into two problems (fingering patterns in CO2 injection, and thermal plumes arising from underground nuclear tests) made possible by the massive computational power provided by Jaguar, the 5294 processor XT3 at ORNL/NCCS. Chair/Speaker Details: Richard Tran Mills Oak Ridge National Laboratory Chuan Lu Los Alamos National Laboratory Peter C. Lichtner Los Alamos National Laboratory