A solution for transverse thermal conductivity of composites with quadratic or hexagonal unidirectional fibres

Abstract

A solution for the transverse thermal conducti vity (K e ) of unidirectional fibre arrays, quadratic and hex agonal, is developed analytically. The solution integrates the thermal conductivity of fibre (K f ) and fluid (K m ) based on electricity analogy without thermal contact resistance (R c ) at the fibre/fluid interface. The expression K e is a func tion of K f and K m , as well as of the fibre volume fraction (V f ). In this article, K e values of four composites were pre dicted and verified by computational fluid dynamics (CFD) simulations. The results showed good agreement when the ratio of K f /K m is close to 1. An increase in the ratio or V f gives poorer agreement owing to the local temperature gradient at the fibre/fluid interface. CFD simulation also showed that K e is decreasing as the R c value increases.