Thermal wave crystals based on dual-phase-lag model

Thermal wave crystals based on the dual-phase-lag model are investigated in this paper by both theoretical analysis and numerical simulation to control the non-Fourier heat conduction process. The transfer matrix method is used to calculate the complex dispersion curves. The temperature field is calculated by the finite difference time domain method. The results show that thermal band-gaps exist due to the Bragg-scattering. The key parameters characterizing the band-gaps are analyzed. The thermal wave impedance and mid-gap frequencies are introduced to predict band-gaps theoretically. Our results show that the larger the difference in the thermal wave impedances is, the wider of the thermal band-gaps will be. This study demonstrates a type of the thermal metamaterials which have potential innovative applications such as thermal imagining, thermal diodes and thermal waveguides for energy transmission.