scholarly journals Variational approach to solving the spectral Boltzmann transport equation in transient thermal grating for thin films

2016 ◽  
Vol 120 (2) ◽  
pp. 025103 ◽  
Author(s):  
Vazrik Chiloyan ◽  
Lingping Zeng ◽  
Samuel Huberman ◽  
Alexei A. Maznev ◽  
Keith A. Nelson ◽  
...  
Keyword(s):  
Thin Films ◽  
Transport Equation ◽  
Variational Approach ◽  
Boltzmann Transport Equation ◽  
Boltzmann Transport ◽  
Thermal Grating ◽  
Transient Thermal

scholarly journals Non-diffusive relaxation of a transient thermal grating analyzed with the Boltzmann transport equation

2013 ◽  
Vol 114 (10) ◽  
pp. 104302 ◽  
Author(s):  
Kimberlee C. Collins ◽  
Alexei A. Maznev ◽  
Zhiting Tian ◽  
Keivan Esfarjani ◽  
Keith A. Nelson ◽  
...  
Keyword(s):  
Transport Equation ◽  
Boltzmann Transport Equation ◽  
Boltzmann Transport ◽  
Thermal Grating ◽  
Transient Thermal ◽  
Diffusive Relaxation

scholarly journals Variational approach to extracting the phonon mean free path distribution from the spectral Boltzmann transport equation

2016 ◽  
Vol 93 (15) ◽  
Author(s):  
Vazrik Chiloyan ◽  
Lingping Zeng ◽  
Samuel Huberman ◽  
Alexei A. Maznev ◽  
Keith A. Nelson ◽  
...  
Keyword(s):  
Transport Equation ◽  
Free Path ◽  
Variational Approach ◽  
Boltzmann Transport Equation ◽  
Mean Free Path ◽  
Boltzmann Transport

DSMC for Phonon Transport in Solid Thin Films

2009 ◽  
Author(s):  
Mitsuhiro Matsumoto ◽  
Masaya Okano
Keyword(s):  
Heat Transfer ◽  
Thin Films ◽  
Relaxation Time ◽  
Transport Equation ◽  
Boltzmann Transport Equation ◽  
Thermal Design ◽  
Dynamics Simulation ◽  
Boltzmann Transport ◽  
Phonon Dynamics ◽  
Solid Thin Films

As the scale of electronic devices decreases, heat transfer analysis and thermal design becomes more important. In particular, heat transfer through various solid thin films is strongly affected by thickness dependence of thermal conductivity and interfacial thermal resistance. Analysis of phonon dynamics based on a linearized Boltzmann transport equation, or the so-called relaxation time approximation, has been widely used, but detailed analysis using molecular dynamics simulation reveals that couplings among various phonon modes can affect the energy transfer. In this study, we propose a DSMC scheme to simulate phonon dynamics starting from the original Boltzmann transport equation. In contrast to the linearized model, this scheme requires no relaxation time as an input parameter, and we can investigate the couplings among phonons with different modes, although we have to assume some appropriate model of phonon-phonon collisions. As a test calculation, energy flux was evaluated for model thin films of various thicknesses, and a phenomenon similar to the Casimir limit was retrieved. This scheme will enable us to include other factors, such as phonon-electron couplings.

Analytical Solutions of Enhanced Gray Boltzmann Transport Equation on Transient Thermal Grating and Time-Domain Thermoreflectance Experiments

2017 ◽  
Author(s):  
Dadong Wang ◽  
Zhengxian Qu ◽  
Yanbao Ma
Keyword(s):  
Experimental Data ◽  
Data Analysis ◽  
Transport Equation ◽  
Heat Transport ◽  
Analytical Solutions ◽  
Time Domain ◽  
Boltzmann Transport Equation ◽  
Boltzmann Transport ◽  
Transient Thermal ◽  
Experimental Data Analysis

As reported by many studies, Fourier’s law breaks down in micro/nanoscale due to the nondiffusive heat transport. To account for the nondiffusive heat transport, high-fidelity nondiffusive models with good efficiency for the experimental data analysis in nanothermometry are necessary but unfortunately missing. In this paper, based on a validated enhance Gray Boltzmann transport equation, we offer the analytical solutions for two important nanothermometry techniques, namely the transient thermal gratings (TTG) and time-domain thermoreflectance (TDTR) experiments. The analytical solutions obtained by inverse Fourier transform are compared to the experimental signals in both TTG and TDTR cases. The excellent agreements between the analytical solutions and the experiments demonstrate the applicability of the EG-BTE in experimental data analysis as an efficient replacement of Fourier’s law.

Sign in / Sign up

Export Citation Format

Share Document