Discovering correlations between metal foam thermal characteristics and non-Fourier behavior

TL;DR

This study develops a numerical model to analyze the complex heat transfer mechanisms in metal foams, revealing the limitations of classical models and highlighting the influence of geometric features on thermal behavior.

Contribution

The paper introduces a one-dimensional, time-dependent model that incorporates multiple heat transfer modes and demonstrates the applicability of the Guyer--Krumhansl equation for porous materials.

Findings

Classical Fourier models are inadequate for metal foam thermal analysis.

Cavity size and arrangement significantly affect temperature distribution.

Guyer--Krumhansl equation effectively describes non-Fourier heat behavior.

Abstract

Due to their low density and large specific surface area, metal foams are increasingly used as cellular materials that combine excellent structural and thermal properties. Their cellular structure makes them particularly suitable for use in heat exchangers, insulation, and fire protection layers. The heat transport that takes place within them is a complex phenomenon characterized by the simultaneous presence of heat conduction, heat transfer, and heat radiation, making their modeling a significant challenge. The aim of the research is to develop a one-dimensional, time-dependent, discrete numerical model capable of describing the effective thermal behavior of metal foams. The model takes into account heat conduction through the solid phase, conductive heat transfer in the closed cavities, thermal radiation between the pore walls, and by-passing heat conduction around the cavity. The results highlight that geometric features such as cavity size and arrangement have a significant impact on temperature distribution and confirm that classical Fourier-based models are not accurately applicable to porous materials, but the Guyer--Krumhansl equation is an adequate candidate. Furthermore, we correlated the static and dynamic thermal diffusivity with the metal foam parameters, showing a significant sensitivity to the cavity thermal attributes.