Simulation of Nanoscale Phonon Heat Transfer Using Lattice Boltzmann Method

• Main Authors: Chung-Dao Chen, 陳俊道
• Other Authors: 楊照彥
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/44949540530453412693

碩士 === 臺灣大學 === 應用力學研究所 === 98 === Current microfabrication technologies have allowed the semiconductor industry, photovoltaic industry and microelectromechanical system to produce smaller devices. Microscopic heat transfer differs from macroscopic. Micro-scale heat transfer no longer follows the Fourier law. In macroscopic scale, substance is considered as continuum, and the transport phenomena can be described by macroscopic governing equations. As the size shrinks, heat carriers become rarefied when characteristic length of the thin film is comparable with the molecule mean free path. Because the frequency of the carriers collision decreases, we need to consider motions and interactions of the individual molecules. 　　This article uses Lattice Boltzmann Method to solve phonon Boltzmann-BGK equation and simulate heat transfer in the thin film with different material arrangement. Several geometries are studied including: Si thin film, Ge-Si embedded supper lattice, Ge-Pore embedded supper lattice and Ge-Si compacted supper lattice. This research uses periodic boundary and IDMM interface boundary. Results suggest that reducing feature size will decrease the thermal conductivity, and temperature will become non-continuum distributions in the interface. And the effective thermal conductivity changes not only with the length of the thin film, but also with the boundary thermal resistance.