Numerical simulation on convective heat transfer characteristics in porous media based on the digital rock technology

Abstract

Convective heat transfer in porous media has attracted great academic interests due to the complex geometry and the upscaling challenges. In this paper, the 3-D pore structures inside porous media is extracted with help of the digital rock technology, and the pore-scale convective heat transfer characteristics in the complex geometry domain is numerically investigated. A novel method is proposed on determination of the hydraulic characteristic sizes, including the equivalent diameter and heat transfer surface areas, of the transport process in porous media. After comprehensive validation of the numerical scheme, the convective heat transfer characteristics is thoroughly studied in the case of fluid with inlet temperature of 293 K flowing through the porous media with constant temperature of 353 K under different pressure drop conditions. Based on the obtained temperature field inside the core, the local convective heat transfer coefficient as well as the local Nusselt number (Nu) is obtained, which shows the obvious inlet behavior in the heat transfer process. Parameter investigations on the pore sizes and the fluid medium are also performed, and a correlation between Nu and Reynolds number (Re) and Prandtl number (Pr) is obtained. It is expected the reported work could help understanding the convective heat transfer process in porous media and therefore guiding the relevant industrial practices.