On the scatter of experiments done with open-cell metal foam in open literature

Abstract

This paper reviews the available methods to study thermal applications with open-cell metal foam. For experimental research, the focus is on the repeatability of the experiments. Especially for open-cell metal foam, this is a major concern. Most published studies only report porosity and the number of pores per linear inch (PPI-value). In this work several points are raised why these values are not enough to characterize a three dimensional foam structure. A different approach, which is studied in this paper, is to characterize the foam using μCT scans with small voxel sizes. The results of these scans are compared with frequently used correlations from open literature to calculate parameters like surface-to-volume ratio. Large differences with the correlations are observed. It is therefore recommended that any kind of experimental work using open-cell metal foam reports a proper geometrical characterization in order that one can repeat the experiments.