Forced convection heat transfer: A comparison between open-cell metal foams and additive manufactured kelvin cells

Abstract

The Kelvin cells are normally applied to represent the open-cell metal foams for simulation due to the similar pore structure. However, the experimental comparison between Kelvin cells and open-cell metal foams is rarely reported. This study compares the forced convective heat transfer properties of four Ni70Cr30 metal foams and one GH4169 Kevin cells manufactured from additive manufacturing. The results indicate that the pressure drop and overall heat transfer coefficient (HTC) increase with the increase of PPI, while decreasing with the increase of porosity. Moreover, the comparisons between present data and data from the literature prove the reasonability of the experiments. The pressure drop and overall HTC of Kelvin cells are 64.4% and 12.3% higher than open-cell metal foams, while showing 26.2% lower overall heat transfer performance at 6 m/s. The pore structure, thicker skeleton, higher porosity, and surface roughness of Kelvin cells contribute to the higher pressure drop than open-cell metal foams. The comparison among experimental correlations and present data indicates that the correlations for predicting the behavior of open-cell metal foams could not be used directly to predict Kelvin cells.