EFFECTIVE THERMAL CONDUCTIVITY OF UNIDIRECTIONALLY ORIENTED COTTON FIBER ASSEMBLY

Abstract

The effective thermal conductivity both perpendicular and parallel to fiber axes (the former is named perpendicular arrangement and the latter is named parallel arrangement) of unidirectionally oriented cotton fiber assembly was measured, and was discussed in terms of the model analyses presented in previous papers.1), 3) The results gave the following conclusions.(1) The experimental results show that the effective thermal conductivity for both perpendicular arrangement and parallel arrangement of unidirectionally oriented fiber assembly falls with the increase of the volumetric ratio until it reaches a minimum value. And it rises with further increase of the volumetric ratio. However, the rate of rise is very little for the case of perpendicular arrangement, but is large for the case of parallel arrangement. The volumetric ratio at the minimum of the effective thermal conductivity for the parallel arrangement is lower than that for the perpendicular arrangement.(2) The value of the effective thermal conductivity for the parallel arrangement is larger than that for the perpendicular arrangement. This is expected due to the difference of the radiative heat transfer between fibers and a plate from the model analyses prescribed in the previous papers.