Benchmarking of FEHM Control Volume Finite Element Solver

Abstract

Numerical modeling of groundwater and geothermal problems has expanded in the past few years due to the increase in computational power and software. The size and complexity of solutions attempted has grown in step with computational abilities. Problems with larger numbers of total nodes, with complex geology involving faulting, as well as coupling of multiple physical processes (geothermal, CO2 sequestration) are now being attempted. Los Alamos National Laboratory (LANL) has invested over 50 man-years of effort into the FEHM control volume finite element solver over the past number of decades. The code has been used on US EPA Superfund sites, low and high level nuclear waste sites, and a variety of fundamental hydrogeological applications. The code allows for complex coupling of processes including non-isothermal models and can solve more complex problems than existing commercial codes. LANL and SoilVision Systems Ltd., have combined efforts to offer groundwater and geothermal numerical modeling solutions of larger and more complex systems. In order to gain confidence in the combined front end, solver, and back end visualization system, a number of benchmarks have been created in order to document performance. This paper presents the results of benchmarks created to test the performance of the new groundwater and geothermal modeling system. Performance of the system is discussed as well as challenges and hurdles encountered in the collaboration. The ability of the system to scale up to model field-scale systems will be discussed.