Lee Jonghoon, Roy Ajit K, Farmer Barry L
Thermal Sciences and Materials Branch, Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright Patterson Air Force Base, Ohio 45433, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 May;83(5 Pt 2):056706. doi: 10.1103/PhysRevE.83.056706. Epub 2011 May 16.
The interface thermal resistance becomes more and more important as device miniaturization for better performance renders a large surface-to-volume ratio and invariably requires a device design with multiple materials inducing thermal interfaces across the material heterogeniety. Toward developing a comprehensive computational methodology for thermal transport prediction, incorporating the interface effects in a heterogeneous medium, a novel boundary collision rule is devised in the lattice Boltzmann computational scheme to realize a thermal interface between phonon gases with dissimilar dispersion relations. Consistent with the Callaway collision operator for Umklapp process, the interface phonon collision process is regarded as a linear relaxation mechanism toward the local pseudo-equilibrium phonon distribution, which is uniquely defined by the energy conservation principle. The Kapitza length and the interface thermal resistance are determined by the relaxation parameter and the local phonon properties. The implementation of the proposed mesoscopic boundary collision rule in the lattice Boltzmann computational framework provides a methodology of predicting the thermal properties of a heterogeneus medium incorporating both normal and Umklapp collision processes of phonon.
随着设备小型化以实现更好的性能，从而导致较大的表面积与体积比，并且总是需要采用多种材料的设备设计，这会在材料异质性上产生热界面，界面热阻变得越来越重要。为了开发一种用于热传输预测的综合计算方法，将界面效应纳入非均匀介质中，在格子玻尔兹曼计算方案中设计了一种新颖的边界碰撞规则，以实现具有不同色散关系的声子气体之间的热界面。与用于倒逆过程的卡洛威碰撞算符一致，界面声子碰撞过程被视为朝向局部伪平衡声子分布的线性弛豫机制，该分布由能量守恒原理唯一确定。卡皮察长度和界面热阻由弛豫参数和局部声子特性决定。在格子玻尔兹曼计算框架中实施所提出的介观边界碰撞规则，提供了一种预测包含声子的正常和倒逆碰撞过程的非均匀介质热性质的方法。
