ABSTRACT Thermal wave, namely wavelike behavior of heat propagation in transient heat conduction, enjoys much attention due to the recent investigations into phonon hydrodynamics in low-dimensional materials. In this paper, an improved phonon Monte Carlo (MC) simulation algorithm is developed based on the Callaway’s dual relaxation time approximation model, which can deal with the coupling of normal and resistance scattering processes. Via the method, more thermal wave evidences are observed from the microscopic view of phonons, including overshooting and diffraction. Furthermore, the ballistic and hydrodynamic thermal waves are deeply studied. Two kinds of dissipation are found to exist in thermal waves, namely spatial dissipation and resistance dissipation. The former keeps the conservation of phonon momentum, but it lengthens the wavelength and decreases the peak temperature. The latter destroys the phonon momentum and keeps the original profile, lowering the peak temperature. Finally, phonon transport phenomena in Ziman hydrodynamic regime and diffusive regime are investigated, by introducing the scattering probability. The propagation tendency of thermal energy is found to decrease with the increasing scattering probability. The investigations into phonon hydrodynamics help to understand the heat transport characteristics and improve thermal management in low-dimensional materials.

中文翻译：

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声子蒙特卡罗模拟中声子流体动力学系统中的热波

摘要 热波，即瞬态热传导中热传播的波状行为，由于最近对低维材料中声子流体动力学的研究而备受关注。本文基于Callaway的双弛豫时间近似模型，开发了一种改进的声子蒙特卡罗（MC）仿真算法，该算法可以处理法向散射和电阻散射过程的耦合。通过该方法，可以从声子的微观角度观察到更多的热波证据，包括超调和衍射。此外，对弹道和流体动力热波进行了深入研究。发现热波中存在两种耗散，即空间耗散和电阻耗散。前者保持声子动量守恒，但它延长了波长并降低了峰值温度。后者破坏声子动量并保持原始轮廓，降低峰值温度。最后，通过引入散射概率，研究了子曼流体动力学状态和扩散状态中的声子传输现象。发现热能的传播趋势随着散射概率的增加而降低。对声子流体动力学的研究有助于了解低维材料的热传输特性并改善热管理。通过引入散射概率。发现热能的传播趋势随着散射概率的增加而降低。对声子流体动力学的研究有助于了解低维材料的热传输特性并改善热管理。通过引入散射概率。发现热能的传播趋势随着散射概率的增加而降低。对声子流体动力学的研究有助于了解低维材料的热传输特性并改善热管理。