Mixing in Porous Media — Lesson 2

This lesson covers the concept of flow through porous media, focusing on miscible displacement and the mixing process within a porous medium. It explains how to characterize this mixing and draw inferences about pore transport from the signatures at the outlet. The lesson also discusses the concept of residence time and how it affects the flow of fluid through the porous medium. It further delves into the impact of a parabolic velocity profile on the dispersion of a pulse moving through a capillary, a phenomenon known as Taylor dispersion. The lesson concludes with a brief introduction to the governing equations and boundary conditions used to analyze this dispersion.

Video Highlights

01:06 - Explanation of residence time and its impact on fluid flow
04:18 - Examination of the effects of a step change in concentration
16:01 - Introduction to Taylor dispersion in a capillary
19:25 - Explanation of the governing equations and boundary conditions

Key Takeaways

- Miscible displacement refers to the process where a fluid is injected into a porous medium, mixing with the resident fluid.
- The residence time, calculated as the pore volume divided by the flow rate, is crucial in determining when a pulse or step change will show up at the outlet.
- In the case of a parabolic velocity profile, the pulse moving through a capillary gets stretched, leading to Taylor dispersion.
- The governing equations and boundary conditions are essential tools in analyzing the dispersion of a pulse in a porous medium.