Skip to main content
U.S. flag

An official website of the United States government

Numerical simulation of double‐diffusive finger convection

January 1, 2005

A hybrid finite element, integrated finite difference numerical model is developed for the simulation of double‐diffusive and multicomponent flow in two and three dimensions. The model is based on a multidimensional, density‐dependent, saturated‐unsaturated transport model (SUTRA), which uses one governing equation for fluid flow and another for solute transport. The solute‐transport equation is applied sequentially to each simulated species. Density coupling of the flow and solute‐transport equations is accounted for and handled using a sequential implicit Picard iterative scheme. High‐resolution data from a double‐diffusive Hele‐Shaw experiment, initially in a density‐stable configuration, is used to verify the numerical model. The temporal and spatial evolution of simulated double‐diffusive convection is in good agreement with experimental results. Numerical results are very sensitive to discretization and correspond closest to experimental results when element sizes adequately define the spatial resolution of observed fingering. Numerical results also indicate that differences in the molecular diffusivity of sodium chloride and the dye used to visualize experimental sodium chloride concentrations are significant and cause inaccurate mapping of sodium chloride concentrations by the dye, especially at late times. As a result of reduced diffusion, simulated dye fingers are better defined than simulated sodium chloride fingers and exhibit more vertical mass transfer.

Publication Year 2005
Title Numerical simulation of double‐diffusive finger convection
DOI 10.1029/2003WR002777
Authors Joseph D. Hughes, Ward E. Sanford, H. Leonard Vacher
Publication Type Article
Publication Subtype Journal Article
Series Title Water Resources Research
Index ID 70029275
Record Source USGS Publications Warehouse
USGS Organization Toxic Substances Hydrology Program