Thermal Equilibrium & Heat Transfer in Porous Media — Lesson 2

This lesson covers the concept of heat transfer in porous media, focusing on thermal equilibrium and non-equilibrium models. It explains the governing equation for heat transfer, highlighting the roles of heat conduction, convection, and accumulation in both solid and fluid phases. The lesson also discusses the implications of thermal equilibrium, boundary conditions, and dimensionless parameters. It further delves into the temperature profile in porous media, explaining how temperature changes over time and space. The lesson also touches on the thermal conductivity of porous solids, providing models to calculate effective thermal conductivity. Lastly, it introduces the mean field model based on volume averaging approach, explaining the concept of thermal non-equilibrium and the exchange of heat between fluid and solid phases.

Video Highlights

00:42 - Explanation of the governing equation for heat transfer
07:02 - Overview of temperature profile in porous media
10:43 - Understanding thermal conductivity of porous solids
14:33 - Introduction to thermal non-equilibrium and mean field model
21:39 - Explanation of the exchange of heat between fluid and solid phases

Key Takeaways

- Heat transfer in porous media involves heat conduction through the solid phase, heat convection through the void phase, and heat accumulation in both phases.
- Thermal equilibrium assumes a single temperature field, while thermal non-equilibrium considers separate temperatures for the fluid and solid phases.
- The thermal conductivity of porous solids differs from that of intact solids due to the presence of voids, and it can be calculated using various models.
- The mean field model based on volume averaging approach provides a comprehensive understanding of heat exchange between fluid and solid phases in porous media.