纳米流体中碳纳米管的热泳及取向性研究

项目名称： 纳米流体中碳纳米管的热泳及取向性研究

项目编号： No.51406098

项目类型： 青年科学基金项目

立项/批准年度： 2015

项目学科： 工程热物理与能源利用学科

项目作者： 董双岭

作者单位： 清华大学

项目金额： 10万元

中文摘要： 由于其特殊的结构，碳纳米管具有很多优异性能，在航空航天、机械电子等领域均有广阔的应用前景。热泳对于碳纳米管在纳米流体中的取向进而对导热性能有着重要的影响。本项目旨在运用热质理论中的热流运动规律解释热泳现象的统一机理，基于温度梯度伴随热流，热流可用热质理论描述的观点，探讨三相热泳与粒子热导率等的关联特性和物理本质，揭示其内在规律；提出与热泳相关但区别于热泳力的热泳升力，指出其方向与局部平均温度梯度垂直，给出随热导率和温度梯度变化率的关系表达式并进行验证；揭示热泳相关力和热流惯性效应对碳纳米管在流体中取向变化的作用规律；针对碳纳米管主轴方向不确定性的问题，结合外场控制和表面修饰等措施，参照数值模拟进行设计，然后实验观测给予验证，以提高主轴取向和温度梯度二者的协同程度，充分发挥碳纳米管高热导率的特点，优化纳米流体的导热性能，从而为纳米流体的强化传热和相关工程应用提供依据和参考。

中文关键词： 热泳；碳纳米管；纳米流体；热质理论；热导率

英文摘要： Due to its special structure, carbon nanotube has many excellent properties , including the very high thermal conductivity, thus it has potential applications in the aerospace , machinery, electronics and other fields. Thermophoresis has significant impact on the orientation of carbon nanotubes and then on the thermal conductivity of nanofluids. The project aims to use the thermomass theory of the heat flow to explain the unified mechanism of thermophoresis, based on the present of temperature gradient along with the heat flow , which can be described by the thermomass theory, the physical nature and its inherent laws of the relationship between the three-phase thermophoresis and thermal conductivity of particles will be revealed. The thermophoretic lift force will be raised which is related to thermophoresis but distinct from thermophoretic force, the direction of force will be pointed out as vertical to the local average temperature gradient, the expression of its relationship with the thermal conductivity and the change rate of the temperature gradient will be given and validated; the role of thermophoretic related forces and inertial effects of heat flow on the orientation change of carbon nanotubes in the fluid will be analyzed. For the uncertainty of the nanotube axis direction, the control strategy for ex

英文关键词： thermophoresis；carbon nanotube；nanofluid；thermomass theory；thermal conductivity