Theresa Kurz, SFB 1313 doctoral researcher at the Department of Hydromechanics and Modelling of Hydrosystems (associated research project C-X3), will give her milestone presentation "Evaporation driven salt precipitation in porous media" on 22 December 2020 at 5 pm CET.
Date: Tuesday, 22 December 2020
Time: 5 pm CET
Title: "Evaporation driven salt precipitation in porous media"
Place: online presentation >>> If you are interested in participating in the lecture, please contact firstname.lastname@example.org
The fundamental understanding of salt precipitation in porous media due to evaporation processes is important in different environmental and technical applications. For example, the salinization of soil in arid and semi-arid zones due to high evaporation rates and poor drainage leads to the reduction of crop yield. During the evaporation of a salt solution, the salt concentration increases at the evaporation front and solid precipitates in the porous medium when the solubility limit is exceeded. Process-controlling properties of salt precipitation depend on interface-driven processes. To understand this processes numerical and experimental investigations on the pore scale are necessary. For this purpose, a pore-network model for one-phase flow is developed, which is able to simulate the precipitation and resulting change in pore space on the pore-scale. Further two-phase micro-CT experiments on salt-precipitation processes were conducted at the Oregon State University. A further important issue related to salt precipitation are density-driven instabilities. The increase in salt concentration results in an increase of density which can lead to the formation of fingers. Thereby, an advective flux transports the accumulated salt downwards and prevent a further increase of concentration and precipitation. The formation of density-driven instabilities is investigated numerically on the REV-scale to identify the dependence on different parameters like the permeability.