Effect of Fin Orientation and Forced Convection on the Performance of Metal Foam Fins using a μ-CT Scan Based 3D CFD Model

Khaled S Al-Athel,Moayed Al-Harbi

doi:10.23977/metf.2017.11001

Abstract

Metal foams are very attractive materials for thermal and electronic packaging applications due to their improved heat transfer capabilities. Their improved heat transfer effective properties are due to the relatively large contact area they possess because of their cell structure. This comes at the expense of the pressure drop. This work presents a methodology based on μ-CT scan to develop a realistic metal foam 3D model. The model is validated with experiments and used to study the behavior of the metal foam as a fin in terms of the temperature variation within the fin as well as the effect of the airflow velocity and fin orientation to the pressure drop. Results showed two major observations. First, this methodology could be used to identify a velocity value at which the fin orientation becomes obsolete and has no effect on the temperature variation. Second, the pressure drop alone could not be used to assess the fin, but also the fin orientation has to be taken into account to examine the total pressure drop.

Highlights

Open cell metal foams have been getting more attention recently in heat transfer and heat recovery applications
Metal Foam computational fluid dynamics (CFD) Analysis This study focuses on the effect of two parameters on the metal foam fin performance, the orientation and the forced convection air velocity
We look into the maximum temperature variation within the metal foam fin as a function of airflow velocity

Summary

Introduction

Open cell metal foams have been getting more attention recently in heat transfer and heat recovery applications. The unit cell model was used to compute the effective thermal conductivity and analyse the heat transfer at the gas-solid interface This approach of the 3D geometrical construction is based on the Lord Kelvin’s model and is not practical for performance analysis of thermal applications. It is of importance to note that the foam geometry used was bigger than a unit cell, which is required to capture the number of pores per inch (PPI) This has an advantage of being able to look at the cell level to extract any needed data, in addition to studying the thermal behavior of the heat sink component as a whole. This work utilized a heat sink μ-CT scan model fin-size model using CFD analysis

Metal Foam μ-CT Scan Model

Results and Discussion

Pressure Drop

Conclusions