Convective heat transfer characteristics of flow through open-cell metal foam considering real structural geometry

Abstract

This study demonstrates numerical prediction of temperature and velocity field when fluid flows through the real 40 PPI metal foam structure extracted by the 3-D μ-CT method. The results are compared to those obtained using structured model and experimental data. The effects of the hollowness of a metal foam ligament on the heat transfer characteristics are presented, and an empirical correlation is suggested for estimating the corresponding Nusselt number. The numerical results clearly show that the hollowness directly affects the heat transfer characteristics, and the Nusselt number for hollowness of 0.79 was about 40% lower than that for a solid ligament. An extended correlation was derived through thermodynamic analysis and numerical results. The experimental data verified that the proposed correlation is appropriate for estimating the Nusselt number for open-cell metal foam with hollow ligaments.