Thermohydrologic Modeling: Coupling Navier-Stokes Models of Gas, Moisture, and Heat Flow in Underground Engineered Systems with Porous-Media Models in Fractured Rocks
Abstract
Combined free and porous flows occur in a wide range of natural and engineered systems such as coupled transport processes driven by underground-engineered systems. One potential application for modeling these coupled flow processes is related to the emplacement of heat-generating radioactive waste package in tunnels lying above the water table. This example involves the flow of gas and moisture in large open tunnel and gas- and liquid-phase flow in the surrounding fractured, porous rocks. This study aims to develop a method of coupling the Navier-Stokes equations and the Darcy's law to achieve a more rigorous representation of all major flow and transport processes in underground tunnels and surrounding fractured host-rocks. While the thermohydrologic (TH) processes in host-rocks are treated based on porous-medium Darcy-flow approximations, the Navier-Stokes modeling is applied to describe in-tunnel flow behaviors (natural convection, realistic gas/moisture movement, turbulent flow conditions, etc.). The governing equations are numerically solved by a finite-element scheme in the NUFT code. Some numerical simulation results shown in this presentation provide environmental conditions that engineered systems would experience, which, therefore, may be useful for engineered system design analysis and performance assessment. This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFM.H21E1053H
- Keywords:
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- 1899 General or miscellaneous;
- 1875 Unsaturated zone