| 基于格子Boltzmann方法的复合材料微尺度传热特征研究 |
| Alternative Title | Study on the Microscale Thermal Transfer Characteristic of the Composite Material Based on Lattice Boltzmann Method
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| 冯蕾蕾 |
| Thesis Advisor | 高原文
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| 2008-05-31
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| Degree Grantor | 兰州大学
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| Place of Conferral | 兰州
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| Degree Name | 硕士
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| Keyword | 微尺度传热
格子Boltzmann方法
有效热导率
接触热阻
尺寸效应
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| Abstract | 过去的20年来随着半导体技术和微/纳电子机械系统(Micro Electro Mechanical Systems)技术的飞速发展，微/纳米器件与结构的力-热-磁-电多场耦合行为得到人们的广泛关注。大量试验表明，当系统尺度微细化以后，其传热规律与常规尺度下的不同．即会出现所谓的尺度效应。散热问题成为影响微/纳米器件与结构性能的关键因素之一。
本文基于玻尔兹曼(Boltzmann)输运理论及相关的格子 Boltzmann方法首先给出了计算热传导问题的格子 Boltzmann 方法二维九速不可压缩热模型以及恒温、绝热、热阻边界条件的处理方式。在此基础上探讨了圆形，椭圆形，矩形的1-3型复合材料的传热特征和等效热导率等。研究了夹杂材料在横向谐变磁场下产生涡电流时的热传导和导体内部有电场时的热传导问题。讨论了考虑接触热阻情况下圆形，矩形夹杂的1-3型复合材料的传热特征和等效热导率等，给出了给定时刻下，结构上的温度分布特征，以及不同组分比，不同反射系数 对有效热传导系的影响。模拟了微纳米尺度下夹杂复合材料的传热特征，以及热导率与结构尺寸和反射系数 的变化关系和结构内温度的分布特征。
通过本文对纳米结构材料传热的研究表明，格子Boltzmann方法是一种有效的研究微纳米尺度传热问题的数值方法。尺寸效应和接触热阻是影响有效热导率的重要因素。 |
| Other Abstract | In the past two decades, as the development of semi-conductor technique, micro electro mechanical systems (MEMS) and nano electro mechanical systems (NEMS). The mechanics-thermal-electromagnetic behaviors of nano-devices or nano-structure have been paid more attention. Numbers of experiment indicated that the heat transfer is different from in macro scale when the characteristic dimension reduced to nano-microscale. The heat transfer characteristic of nano-microscale structures or nano-microscale devices become one of important topics in the design of MEMS and NEMS.
Based on the Boltzmann transport theory and Lattice Boltzmann Method, firstly a two-dimensional nine-speed (D2Q9) lattice Boltzmann incompressible thermal model is introduced, and the isothermal, adiabatic, thermal contact resistance boundary condition are also introduced. Then a numerical code based on the lattice Boltzmann method is developed to quantitatively simulate the thermal conductive characteristics of the composite material considering contact thermal resistance with the different shape’s inclusions. Heat transfer of composite materials under transverse harmonic magnetic field and electric field in the conductor are also discussed. With consideration of contact thermal resistance, the thermal conductive characteristics of the composite material with the different shape’s inclusions are studied. Some results on the characteristics of heat transport characteristics, such as the temperature distribution in the structure at a time-point are presented respectively. The effective thermal conductivities for the composite material with the different shape’s inclusions are obtained. Further Temperature distribution in the structure and the relationship between effective thermal conductivity and the size of structure, reflection coefficient, arealso studied.
From above studies, we found that Lattice Boltzmann Method is a valid method for nano-microscale heat transfer. Thermal contact resistance and size effects are important factor for affecting effective thermal conductivity. |
| URL | 查看原文
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| Language | 中文
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| Document Type | 学位论文
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| Identifier | https://ir.lzu.edu.cn/handle/262010/226267
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| Collection | 土木工程与力学学院
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Recommended Citation
GB/T 7714 |
冯蕾蕾. 基于格子Boltzmann方法的复合材料微尺度传热特征研究[D]. 兰州. 兰州大学,2008.
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