Heat Reduction by Thermal Wave Crystals

TL;DR

This paper demonstrates that thermal wave crystals, based on non-Fourier heat conduction models, exhibit band gaps due to Bragg scattering, with potential applications in thermal management technologies.

Contribution

It introduces a theoretical and numerical analysis of thermal wave crystals using the Cattaneo-Vernotte model, including band structure calculation and a method to predict band gap frequencies.

Findings

Band gaps exist due to Bragg scattering in thermal wave crystals.

A calculation method for mid-gap frequency prediction is proposed.

Thermal wave crystals have potential applications in thermal imaging and diodes.

Abstract

Non-Fourier heat conduction models assume wave-like behavior does exist in the heat conduction process. Based on this wave-like behavior, thermal conduction controlled in a one-dimensional periodical structure, named thermal wave crystal, has been demonstrated through both theoretical analysis and numerical simulation based on the Cattaneo-Vernotte (CV) heat-conduction model. The transfer matrix method and Bloch analysis have been applied to calculate the band structure of thermal wave propagating in thermal wave crystals. And the temperature responses are obtained by using the FDTD method, which is also used to verify the correctness of the band structure. The results show that band gaps do exist due to the Bragg scattering. Then, a calculation method to predict the mid-gap frequency of band gaps for the thermal wave crystal has been introduced in this Letter. And key parameters determining the band gaps have been discussed. This study shows the potential applications of this novel mechanism, such as thermal imagining, thermal diodes and thermal waveguides.