Subjects: Physics >> Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics submitted time 2022-10-17
Abstract:
The acoustic mismatch model and diffuse mismatch model are widely used in the calculation of interfacial thermal conductance. These two models are respectively based on the assumption of extremely smooth and rough interfaces. Due to the great difference between the actual interface structure and the two hypotheses, the prediction of these two models deviate greatly from the actual interfacial thermal conductance. The recently proposed mixed mismatch model considers the effect of interface structure on the ratio of phonon specular transmission to diffuse scattering transmission, and the prediction accuracy is improved. However, this model requires molecular dynamics simulation to obtain phonon information at the interface. In this paper, the mixed mismatch model is simplified by introducing the measured roughness value, and the influence of interface structure on the contact area is taken into account to achieve a simple, fast and accurate prediction of interface thermal conductance. Based on this model, the interfacial thermal conductance of metals (aluminum, copper, gold) and semiconductors (silicon, silicon carbide, gallium arsenide, gallium nitride) are calculated and predicted. The results of Al/Si interface are in good agreement with the experimental results. This model is not only helpful to understand the mechanism of interface heat conduction, but also helpful to compare with the measurement results.
Subjects: Materials Science >> Nanoscience and Nanotechnology submitted time 2021-03-26
Abstract: Solar stills have attracted increasing attentions in recent years due to its ability of simple construction and eco-friendly. In this study, the weighted values of environment factors on evaporation efficiency are obtained by using a well-established machine learning algorithm, random forest. To test the advancement between random forest and mathematical data analysis, two traditional data science methods, pair wise plots and Pearson correlation analysis, were conducted for comparison. Experimental data used in analysis were collected from around 100 articles since 2014. The results indicated that thermal design was the most significant factor that contributes in high-efficiency solar evaporation. It will promote the studies on evaporation efficiency solar stills. "
Peer Review Status:Awaiting Review
Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics Subjects: Energy Science >> Energy Science (General) submitted time 2017-03-22 Cooperative journals: 《工程热物理学报》
Abstract:实现聚合物热导率调控,对扩大其在柔性集成电路热管理中的应用非常重要。过去的十年中,学者们从纳米结构材料的制造方面做了大量工作,但是各种各样的官能团与聚合物导热性质的关系仍没有明确。本文使用分子动力学方法,通过原子质量修饰简化模型,探究了碳链聚合物单链的热导率与多种等效取代基的关系。研究发现,氢原子质量修饰能显著调控碳链聚合物单链的热导率,随着原子修饰质量的增加,热导率单调递减。分析表明,氢原子质量修饰会影响与其成键的碳原子的振动模式,越大的原子修饰质量会越多地散射碳链中的低频声子,因而使碳链聚合物单链的热导率显著降低。本研究对理解聚合物热导率调控与多种取代基之间的关系具有指导意义。