Dissertation Defense: Quantitative investigation on submicron heat conduction with ab-initio phonon Boltzmann transport equation
Date: 2023/05/29 - 2023/05/29
Dissertation Title: Quantitative investigation on submicron heat conduction with ab-initio phonon Boltzmann transport equation
Speaker: Yue Hu, Ph.D. candidate at UM-SJTU Joint Institute
Time: May 29th from 2:00 p.m., 2023 (Beijing Time)
Location: Room 503, Longbin Building
Abstract
In the realm of semiconductor devices, composite thermoelectric materials, composite thermal interface materials, and nano-porous media, heat conduction occurs at the submicron scale, which is comparable to the mean free path of phonons. At this scale, the macroscopic Fourier’s law becomes invalid, and non-Fourier phenomena have been widely observed. These non-Fourier phenomena are primarily due to phonon diffusive-ballistic transport, which is governed by the phonon Boltzmann transport equation (BTE). The phonon BTE is essential for
investigating submicron heat conduction. However, several significant challenges hinder the utilization of the phonon BTE. Firstly, the input phonon properties rely on an empirical model with numerous fitting parameters. Secondly, the numerical solution of the phonon BTE results in prohibitive computational costs, especially for practical applications in three dimensions. Lastly, there are notable differences between the phonon BTE and atomic scale methods. As a result of these challenges, the investigation of submicron heat conduction through the use of the phonon BTE remains primarily qualitative. The goal of this dissertation is to address these challenges and quantitatively investigate submicron heat conduction by utilizing the phonon BTE.
Biography
Yue Hu received the B.S. in Energy and power engineering from Xi’an Jiaotong University in 2018. He is currently a Ph.D. candidate at the UM-SJTU Joint Institute, supervised by Prof. Hua Bao. His current research interests include Boltzmann transport equation and nonequilibrium thermal transport.