The Fast-C Simulators for Density-Driven Flow Application to Geothermal Modelling

Abstract

The FAST-C software is designed to run models for densitydriven flow in porous media and in free fluids. The codes are equipped with the GeoShell graphical user interface which allows user-friendly input, control and variation of all relevant parameters. The software has been applied to several problems in which density-driven flow patterns are involved: free and forced convection, oscillatory convection, saltwater intrusion, saltwater upconing, the saltdome problem and the salt-lake problem. While the general code allows the set-up of three-dimensional models, there is a special version for two-dimensional modeling, FAST-C(2D), containing several advanced options. As an application of FAST-C(2D) code a synthetic test-case of geothermal flow is modeled. The mixed convection regime in the example can be characterized by two non-dimensional numbers, the Rayleigh number and a new dimensionless number which relates buoyancy to external forces. The example demonstrates how numerical experiments in the space of dimensionless variables can be used to understand the complex interaction of various processes in a geothermal system.