弹道扩散机制下热波传递的蒙特卡罗模拟  

Thermal Wave Propagation in Ballistic-Diffusive Regime by Phonon Monte Carlo Simulation

作　　者：唐道胜 华钰超 曹炳阳[1] 

机构地区：[1]清华大学航天航空学院热科学与动力工程教育部重点实验室,北京100084

出　　处：《工程热物理学报》2017年第5期1056-1060,共5页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No.51356001);国家自然科学基金创新研究群体(No.51321002)

摘　　要：超短脉冲激光技术在精细加工和微纳米材料热物性测量方面的广泛应用,要求对超快速导热过程有更系统深入的了解。本文利用蒙特卡罗模拟方法研究了声子主导的超快导热过程,并和经典热波模型的结果进行了对比分析。经典热波方程预测了无色散的耗散波;兰贝特边界发射的蒙特卡罗模拟预测了色散的耗散波,而且不同的边界声子发射的模拟结果不同。利用声子玻尔兹曼方程分析了模拟中不同发射方式下热波的色散关系。热波传递过程中的能量均方位移时间关系表明中声子以弹道扩散形式传递。Wide applications of ultra-short pulse laser on micromachining and thermal property measurements make it essential to have systematic understanding on the ultrafast heat conduction. In this work, we investigate the phonon-mediated ultrafast heat conduction by a phonon-traced Monte Carlo （MC） method and make the comparisons between the simulations and the classical thermal wave model. The classical thermal wave model predicts a non-dispersive dissipated wave while the MC simulations with Lambert emission predicts a dispersive dissipated wave, and results are different when boundary phonon emissions are different in the simulations. Dispersion relations of the thermal wave by the MC simulations are obtained from the Boltzmann transport equation. The energy mean square displacement time relations show that thermal wave propagates in phonon ballistic-diffusive regime.

关 键 词：热波 弹道-扩散 蒙特卡罗模拟 能量均方位移 

分 类 号：TK121[动力工程及工程热物理—工程热物理]