etraSim Overview Solve challenging subsurface flow problems with PetraSim PetraSim is the graphical interface for the TOUGH2 family of simulators. Developed at Lawrence Berkeley National Laboratory, TOUGH2 and its derivatives are recognized for their powerful simulation capabilities for fluid flow and heat transfer in porous and fractured media. Click on image to enlarge The TOUGH2 codes have been applied to problems ranging from Yucca mountain groundwater flow to multi-component environmental remediation. PetraSim makes the power of TOUGH2 accessible to modelers through an interactive 3D environment that includes mesh generation, parameter definition, and display of results. PetraSim significantly lowers the barriers to TOUGH2 use by freeing the analyst to focus on the model, while automatically handling the complex details of TOUGH2 input and output files. PetraSim includes TOUGH2, T2VOC, TMVOC, and TOUGHREACT executables.