Statistical Properties of Random Packing and Macroscopic Thermal Conductivity of Sintered Balloons (Re-Examination)

Abstract

This paper simulates the macroscopic thermal conductivities of randomly-packed, sintered balloons for various degrees of sintering and for a wide range of the balloon inner/outer diameter ratio. Although this problem was already studied by Ono et al., we found some errors in their paper, including a critical one. Thus, we re-examine the same theme and correct all errors. Furthermore, we extend its contents and discuss the results in more detail. For practical purposes, we present all the macroscopic conductivities in terms of a simple expression of two balloon's geometrical parameters. "Specific" macroscopic thermal conductivities (i.e., those per weight) are precisely estimated and found to have a peak when the balloons have the diameter ratio larger than approximately 0.8.