Thermal transport exceeding bulk heat conduction due to nonthermal micro/nanoscale phonon populations
While classical size effects usually lead to a reduced effective thermal conductivity, we report here that nonthermal phonon populations produced by a micro/nanoscale heat source can lead to enhanced heat conduction, exceeding the prediction from Fourier's law. We study nondiffusive thermal tra...
| Main Authors: | , , , , |
|---|---|
| 其他作者: | |
| 格式: | Article |
| 出版: |
AIP Publishing
2020
|
| 在線閱讀: | https://hdl.handle.net/1721.1/125057 |
| _version_ | 1826203976593309696 |
|---|---|
| author | Chiloyan, Vazrik Huberman, Samuel Maznev, Alexei A. Nelson, Keith A. Chen, Gang |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Chiloyan, Vazrik Huberman, Samuel Maznev, Alexei A. Nelson, Keith A. Chen, Gang |
| author_sort | Chiloyan, Vazrik |
| collection | MIT |
| description | While classical size effects usually lead to a reduced effective thermal conductivity, we report here that nonthermal phonon populations produced by a micro/nanoscale heat source can lead to enhanced heat conduction, exceeding the prediction from Fourier's law. We study nondiffusive thermal transport by phonons at small distances within the framework of the Boltzmann transport equation (BTE) and demonstrate that the transport is significantly affected by the distribution of phonons emitted by the source. We discuss analytical solutions of the steady-state BTE for a source with a sinusoidal spatial profile, as well as for a three-dimensional Gaussian “hot spot,” and provide numerical results for single crystal silicon at room temperature. If a micro/nanoscale heat source produces a thermal phonon distribution, it gets hotter than that predicted by the heat diffusion equation; however, if the source predominantly produces low-frequency acoustic phonons with long mean free paths, it may get significantly cooler than that predicted by the heat equation, yielding an enhanced heat transport beyond bulk heat conduction. |
| first_indexed | 2024-09-23T12:46:53Z |
| format | Article |
| id | mit-1721.1/125057 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T12:46:53Z |
| publishDate | 2020 |
| publisher | AIP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1250572022-10-01T11:03:43Z Thermal transport exceeding bulk heat conduction due to nonthermal micro/nanoscale phonon populations Chiloyan, Vazrik Huberman, Samuel Maznev, Alexei A. Nelson, Keith A. Chen, Gang Massachusetts Institute of Technology. Department of Mechanical Engineering Massachusetts Institute of Technology. Department of Chemistry While classical size effects usually lead to a reduced effective thermal conductivity, we report here that nonthermal phonon populations produced by a micro/nanoscale heat source can lead to enhanced heat conduction, exceeding the prediction from Fourier's law. We study nondiffusive thermal transport by phonons at small distances within the framework of the Boltzmann transport equation (BTE) and demonstrate that the transport is significantly affected by the distribution of phonons emitted by the source. We discuss analytical solutions of the steady-state BTE for a source with a sinusoidal spatial profile, as well as for a three-dimensional Gaussian “hot spot,” and provide numerical results for single crystal silicon at room temperature. If a micro/nanoscale heat source produces a thermal phonon distribution, it gets hotter than that predicted by the heat diffusion equation; however, if the source predominantly produces low-frequency acoustic phonons with long mean free paths, it may get significantly cooler than that predicted by the heat equation, yielding an enhanced heat transport beyond bulk heat conduction. 2020-05-06T16:02:49Z 2020-05-06T16:02:49Z 2020-04 2019-11 Article http://purl.org/eprint/type/JournalArticle 0003-6951 1077-3118 https://hdl.handle.net/1721.1/125057 Chiloyan, Vazrik et al. "Thermal transport exceeding bulk heat conduction due to nonthermal micro/nanoscale phonon populations." Applied Physics Letters 116, 16 (April 2020): 163102 © 2020 Author(s) http://dx.doi.org/10.1063/1.5139069 Applied Physics Letters Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf AIP Publishing Prof. Gang Chen |
| spellingShingle | Chiloyan, Vazrik Huberman, Samuel Maznev, Alexei A. Nelson, Keith A. Chen, Gang Thermal transport exceeding bulk heat conduction due to nonthermal micro/nanoscale phonon populations |
| title | Thermal transport exceeding bulk heat conduction due to nonthermal micro/nanoscale phonon populations |
| title_full | Thermal transport exceeding bulk heat conduction due to nonthermal micro/nanoscale phonon populations |
| title_fullStr | Thermal transport exceeding bulk heat conduction due to nonthermal micro/nanoscale phonon populations |
| title_full_unstemmed | Thermal transport exceeding bulk heat conduction due to nonthermal micro/nanoscale phonon populations |
| title_short | Thermal transport exceeding bulk heat conduction due to nonthermal micro/nanoscale phonon populations |
| title_sort | thermal transport exceeding bulk heat conduction due to nonthermal micro nanoscale phonon populations |
| url | https://hdl.handle.net/1721.1/125057 |
| work_keys_str_mv | AT chiloyanvazrik thermaltransportexceedingbulkheatconductionduetononthermalmicronanoscalephononpopulations AT hubermansamuel thermaltransportexceedingbulkheatconductionduetononthermalmicronanoscalephononpopulations AT maznevalexeia thermaltransportexceedingbulkheatconductionduetononthermalmicronanoscalephononpopulations AT nelsonkeitha thermaltransportexceedingbulkheatconductionduetononthermalmicronanoscalephononpopulations AT chengang thermaltransportexceedingbulkheatconductionduetononthermalmicronanoscalephononpopulations |