Experimental investigation of double-diffusive finger convection in analog porous media: Preliminary analysis of scaling relationships for low magnitude Rayleigh space

摘要

Double-diffusive finger convection can occur in initially gravitationally stable, two component, miscible fluid systems when components have dissimilar molecular diffusivities and make opposing contributions to the vertical density gradients. The unequal molecular diffusivities allow for different mass transfer rates between system components which creates local buoyant instabilities. This mechanism can contribute to mass transport in porous and fractured systems leading to structured velocity fields with component fluxes that are much greater than predicted by diffusion alone (e.g. Imhoff and Green, 1988). In this paper we present results of experiments designed to investigate double-diffusive finger convection in a two component solutal system at low concentrations (< 7% by mass) within analog porous media.