Numerical and experimental evaluation for density-related thermal insulation capability of entangled porous metallic wire material

Abstract

Entangled porous metallic wire material (EPMWM) has the potential as a thermal insulation material in defence and engineering. In order to optimize its thermophysical properties at the design stage, it is of great significance to reveal the thermal response mechanism of EPMWM based on its complex structural effects. In the present work, virtual manufacturing technology (VMT) was developed to restore the physics-based 3D model of EPMWM. On this basis, the transient thermal analysis is carried out to explore the contact-relevant thermal behavior of EPMWM, and then the spiral unit containing unique structural information are further extracted and counted. In particular, the thermal resistance network is numerically constructed based on the spiral unit through the thermoelectric analogy method to accurately predict the effective thermal conductivity (ETC) of EPMWM. Finally, the thermal diffusivity and specific heat of the samples were obtained by the laser thermal analyzer to calculate the ETC and thermal insulation factor of interest. The results show that the ETC of EPMWM increases with increasing temperature or reducing density under the experimental conditions. The numerical prediction is consistent with the experimental result and the average error is less than 4%.

Keywords

• Entangled porous metallic wire material (EPMWM)
• Virtual manufacturing technology (VMT)
• Thermal resistance network
• Effective thermal conductivity (ETC)
• Thermal insulation factor