Carina Bringedal

Field of work

My research focuses on modeling and simulation of flow and transport. My research follows three paths: (i) flow and transport in porous media, (ii) evolving interfaces, and (iii) improved solver schemes.

Porous media are media consisting of both solid space and void space, in which a fluid can flow. This can for example be sponges or soil. Technical applications like fuel cells also use porous materials. For such porous media I am interested in how to model and simulate flow and transport, in particular when there are coupled processes and interactions between scales. Coupled processes can for example be that the fluid contains a dissolved solute which can precipitate as a solid and hence change the structure of the porous medium. In terms of scales, I am focusing on the pore scale and averaged Darcy scale: on the pore scale one can describe the location of fluid and solid explicitly, while on the averaged Darcy scale one only uses averages like the amount of fluid and solid in a certain volume. Such averaged models are useful when simulating large applications like geothermal reservoirs, but can be difficult to find. Hence, in my research I try to find improved models for how coupled processes interact with each other in these scales, to allow efficient simulations of large applications.

When two (or more) fluids are flowing, there is an evolving fluid-fluid interface between them. Or, if there are mineral and precipitation reactions occurring due to solutes transported with the fluid, there will be an evolving fluid-solid interface due to the flow. Such evolving interfaces are important to model, but difficult to analyze and simulate. For this, I have in the recent years developed phase-field models, which allow for a simpler mathematical treatment and enables more efficient numerical schemes to be used. The phase-field models use a diffuse-interface approach, which means that the evolving interface is modeled as a diffuse transition zone. This is a mathematical approximation, and an important part of my analysis is to make sure to address this approximation.

The processes that I consider in porous media and with the evolving interfaces, result typically in nonlinear, coupled problems. Since my goal is to simulate the resulting model equations in an efficient manner, I am also interested in designing good solver schemes that address the nonlinearities and couplings of the problem.