How to enhance the effective thermal conductivity of composite material based on optimization method?

•A numerical method is used to optimize the distribution of fillers.•The method is validated by the theoretical models.•The final distribution is affected by the temperature gradient of filling location.•Higher effective thermal conductivity is obtained with the optimized distribution.

Filling a finite amount of high thermal conductivity materials into the base material to enhance the ETC (effective thermal conductivity) of the composite has attracted intensive interests, but how to disperse the fillers apparently poses a question. In the present study, we investigate the enhancement of ETC through altering the distribution of the fillers with an optimization method which is inspired by the volume-to-point heat conduction problem. The theoretical model is first validated by the theoretical results of the Parallel and Series models. Then it is used to investigate the way how to fill the high thermal conductivity materials. It is found that the distribution of fillers changes gradually from parallel type to series type as the relative location of temperature gradient of filling location is away from the highest temperature gradient. The closer to the highest temperature gradient, the larger ETC of the composite is. The optimized ETCs are compared with those of the random distributions, which indicate that the distribution obtained by the optimization method can achieve better ETC enhancement than the corresponding random distribution in the range of relative locations between 0.04 and 0.3. The information provided here can be useful for fabricating the composite material.