The Uncertainty in SCHF‐DT Thermal Conductivity Measurements of Lotus‐Type Porous Copper

Lotus‐type porous metals with many straight pores are attractive for use as heat‐sinks because a large heat‐transfer capacity can be obtained, due to the small diameter of the pores. In order to use lotus‐type porous copper effectively as a heat sink, it is important to know the effective thermal conductivity considering the effect of pores on heat conduction in the material. Since these metals have anisotropic pores, a steady‐state comparative longitudinal heat‐flow method for measuring thermal conductivity, referring to an ASTM standard, is better than other methods. So far, the effective thermal conductivity of lotus‐type porous copper has been measured by using specimens of different thickness (the SCHF‐DT method). In this paper, the uncertainty in the effective thermal conductivity of a specimen measured using this method was evaluated by comparison between numerical analysis and current experimental data. The following conclusions were drawn: 1) The uncertainty showed good agreement with the uncertainty analysis; 2) The contribution of the thermal grease thickness was large, based on a combined standard uncertainty analysis; and, 3) The effective thermal conductivity perpendicular to the pores of lotus copper can be measured within 10% uncertainty by this method.