September 25, 2018

« All News

Daria Akhbari Coauthored an Article Entitled "Convective Carbon Dioxide Dissolution in a Closed Porous Medium at Low Pressure" in the Journal of Fluid Mechanics

Daria Akhbari, Ph.D. (California) coauthored an article entitled "Convective Carbon Dioxide Dissolution in a Closed Porous Medium at Low Pressure" in the Journal of Fluid Mechanics on pages 56-87 in Volume 854 in the November 10, 2018 edition. His coauthors were Baole Wen, Li Zhang, and Marc A. Hesse.

Daria is a Senior Staff Scientist based in California focused on groundwater modeling, field work, subsurface sampling, oversight of drilling operations, groundwater remediation, groundwater flow, contaminant transport, and multiphase flow in porous media.

The Journal of Fluid Mechanics, published by the Cambridge University Press, contains authoritative articles covering theoretical, computational and experimental investigations of all aspects of the mechanics of fluids. Each issue contains papers both on the fundamental aspects of fluid mechanics and on their applications to other fields such as aeronautics, astrophysics, biology, chemical and mechanical engineering, hydraulics, materials, meteorology, oceanography, geology, acoustics and combustion.

Motivated by the persistence of natural carbon dioxide (CO2) fields, we investigate the convective dissolution of CO2 at low pressure (below 1 MPa) in a closed system, where the pressure in the gas declines as convection proceeds. This introduces a negative feedback that reduces the convective dissolution rate even before the brine becomes saturated. We analyze the case of an ideal gas with a solubility given by Henry’s law, in the limits of very low and very high Rayleigh numbers. The equilibrium state in this system is determined by the dimensionless dissolution capacity, 𝛱, which gives the fraction of the gas that can be dissolved into the underlying brine. Analytic approximations of the pure diffusion problem with 𝛱>0 show that the diffusive base state is no longer self-similar and that diffusive mass transfer declines rapidly with time. Direct numerical simulations at high Rayleigh numbers show that no constant flux regime exists for 𝛱>0; nevertheless, the quantity F/Cs2 remains constant, where F is the dissolution flux and Cs is the dissolved concentration at the top of the domain. Simple mathematical models are developed to predict the evolution of Cs and F for high-Rayleigh-number convection in a closed system. The negative feedback that limits convection in closed systems may explain the persistence of natural CO2 accumulations over millennial time scales.

More Information

Read the article: Convective carbon dioxide dissolution in a closed porous medium at low pressure.
For consultation regarding convective carbon dioxide dissolution, contact Daria Akhbari at This email address is being protected from spambots. You need JavaScript enabled to view it..
Learn more about Daria at: