Effective thermal conductivity of open-pore metal foams as a function of the base material

Abstract The effective thermal conductivity of open-pore metal foams in combination with the fluids air and water have been investigated in an extended range in relative density and selection of material. This study is conducted to estimate the influence of the thermal conductivities of the combination “metal foam — fluid” λs and λfl on the effective thermal conductivity λe of the open-pore metal foam. Therefore, open-pore metal foams (ρrel = 12.7 % in average) of different base materials are manufactured by respect of significant differences in the thermal conductivity of their bulk material in a range of 24.80 W × (m × K)−1≤λs≤ 402.13 W × (m × K)−1. These samples are saturated by air and water and the effective thermal conductivities of the corresponding combinations are determined. The thereto used method is a transient one and is based on the theory of inturbide temperature fields. The impact of the fluid type on λe is evaluated and its dependence on λs is identified, resulting in a simple expression ...