• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>International journal of numerical methods for heat & fluid flow >An overview of phonon-based heat conduction models and their solution
【24h】

An overview of phonon-based heat conduction models and their solution

机译：基于声子的热传导模型及其解决方案概述

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Purpose - The purpose of this paper is to provide an overview and some recent advances in the models, analysis and simulation of thermal transport of phonons as related to the field of microscale/macroscale heat conduction in solids. The efforts focus upon a fairly comprehensive overview of the subject matter from a unified standpoint highlighting the various approximations inherent in the thermal models. Subsequently, the numerical formulations and illustrations using the current state-of-the-art are provided. Design/methodology/approach - This paper is dedicated to the approximate solution to the relaxation time phonon Boltzmann equation (BE). While original contributions are pointed out and addressed appropriately, the efforts and contributions will be focussed on a relatively complete overview highlighting the field from one unified standpoint and clearly stating all assumptions that go into the approximations inherent to existing models. The contents will be divided as follows: In the first section the authors will give an overview of semi-classical phonon transport physics. Then the authors will discuss the equation of phonon radiative transport (EPRT) and its approximations-the ballistic-diffusive approximation (BDA) and the new heat equation (NHE). Next the authors derive and discuss the C-F model. A numerical discretization method valid for all models is then presented followed by results to numerical simulations and discussion. Findings - From a unified treatment based on the introduction of an energy distribution function, the authors have derived the EPRT and its two well-known approximations: BDA and NHE. For completeness and to provide a vehicle for a general numerical discretization approach, the authors have also included analysis of the C-F model and the parabolic and hyperbolic descriptions of heat transfer along with it. The approximation of angular dependence of phonons in radiation-like descriptions of transport has been given special attention. The assumption of isotropy was found to be of paramount importance in the formulation of position space models for phononic thermal transport. For the thin film problem considered here, the NHE along with the proper boundary condition appears to be the best choice to approximate the phonon BE. Not only does it provide predictions that are in excellent agreement with EPRT, it does not require the discretization of phase space making it far more computationally efficient. Originality/value - The authors hope this work will help dispel the idea that since Fourier's law describes diffusion (under limiting assumptions) and it has shown to be ineffective in describing heat transfer for very thin films, that diffusion cannot describe heat transfer in thin films and one should look to a radiative description instead. If one considers diffusion in the sense of random motion, as invisaged by the original builders of the subject (Smoluchowski, Einstein, Ornstein et al.), instead of a temperature gradient, the idea that diffusion can govern thermal transport at this scale is not surprising. Indeed, the NHE is essentially a diffusion equation that describes the motion of particles up to the point of true randomness (isotropy) as well as thereafter.
机译：目的-本文的目的是提供声子的热传递模型，分析和模拟的概述和最新进展，这些模型与固体中的微尺度/宏观尺度热传导领域有关。从统一的角度着眼于对主题的相当全面的概述，突出了热模型固有的各种近似。随后，提供使用当前最新技术的数字公式和图示。设计/方法/方法-本文致力于松弛时间声子玻耳兹曼方程（BE）的近似解。在指出并适当解决了原始贡献的同时，我们的工作和贡献将集中在一个相对完整的概述上，从一个统一的角度突出显示该领域，并明确说明所有与现有模型固有的近似有关的假设。内容分为以下几部分：在第一部分中，作者将概述半经典声子传输物理学。然后，作者将讨论声子辐射输运方程（EPRT）及其近似值-弹道扩散近似（BDA）和新的热方程（NHE）。接下来，作者得出并讨论了C-F模型。然后提出一种适用于所有模型的数值离散化方法，然后将结果进行数值模拟和讨论。发现-通过基于引入能量分布函数的统一处理，作者得出了EPRT及其两个众所周知的近似值：BDA和NHE。为完整起见，并为一般的数值离散化方法提供了一种工具，作者还包括了对C-F模型的分析以及对热传递的抛物线和双曲线描述。在辐射状的输运描述中，声子的角度依赖性近似值已受到特别关注。发现各向同性的假设对于声子热传输的位置空间模型的制定至关重要。对于此处考虑的薄膜问题，NHE和适当的边界条件似乎是逼近声子BE的最佳选择。它不仅提供与EPRT完全一致的预测，而且不需要相空间离散化，从而大大提高了计算效率。原创性/价值-作者希望这项工作能够消除以下观点：由于傅立叶定律描述了扩散（在有限的假设下），并且已证明在描述非常薄的薄膜的传热方面无效，因此扩散无法描述薄膜的传热而且应该改用辐射的描述。如果按照受试者的原始建造者（Smoluchowski，Einstein，Ornstein等人）的设想，从随机运动的角度考虑扩散，而不是温度梯度，那么扩散就可以控制这种规模的热传输的想法就不成立了。奇怪。实际上，NHE本质上是一个扩散方程，描述了直到真正随机性（各向同性）及其以后粒子的运动。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号