基于表面行波实现微纳通道流动减阻和传热强化的研究

The active control of the heat transfer and flow of the fluid in the micro/nano systems is one of the significant techniques in the micro/nano electromechanical systems (MEMS/NEMS) and other nanotechnologies. This project aims to both reduce the thermal resistance at the liquid/solid interface and increase the velocity slip in micro/nano elements using the travelling surface waves, in which the thermal conductivity of the fluid can be increased and its viscosity can be reduced within one nanometre layer close to the wall, improving the field synergy between the velocity and temperature fields and efficiently enhancing the heat transfer and reducing the drag force of the flow. As a result, we can implement the control of heat transfer and flow of the fluid through the nanochannels. The techniques that will be used in this project include the molecular dynamics (MD) simulations, theoretical analysis and experimental investigations. The MD will be used to simulate the heat transfer and flow of the fluid in nanochannels under the condition of travelling surface waves, analysing and summarising the effects of the propagating direction, amplitude, frequency of travelling surface waves, channel walls, fluid types and channel sizes on the interface thermal resistance, velocity slip, conductivity and viscosity of the fluid. Also, the velocity and temperature fields in micro/nanochannels will be calculated in terms of the coupling with the lattice Boltzmann method, and we will build a model to analyse how the travelling surface waves affect the two fields. Based on this work, we can implement the control of the heat transfer and flow of water in silicon nanochannel arrays. This project will provide the basic principle, database and modelling for the active control of the enhancement of heat transfer and drag reduction of the fluid flow in micro/nano systems by the travelling surface waves.

液体在微纳米系统中传热和流动的主动控制是微纳机电系统及其它纳米技术中的关键问题之一。本项目提出在微纳米器件中利用表面行波来同时减小液固界面热阻和增大速度滑移，提高近壁面纳米尺度范围液体的表观热导率和降低其表观粘度，改善速度场和温度场的协同，有效提高传热量和降低流动阻力，以实现对纳米通道内液体传热和流动的控制。研究拟以分子动力学模拟、理论分析和实验研究为手段，模拟基于表面行波的纳米通道内液体的传热和流动，分析和总结行波传播方向、振幅、频率、壁面和液体种类、通道尺寸等因素对界面热阻、速度滑移、液体表观热导率和粘度的影响机制和规律，耦合介观格子Boltzmann方法计算纳米通道内流场和温度的分布，建立表面行波对它们影响的分析模型，以此为基础实现表面行波对水在硅纳米通道阵列内传热和流动的控制。本项目将为基于表面行波进行微纳米系统中液体传热强化和流动减阻的主动控制提供基本的机理、数据和模型基础。

气/液体在微纳米系统中传热和流动的主动控制是微纳机电系统及其它纳米技术中的关键问题之一。本项目提出在微纳米器件中利用表面行波来增大液固界面速度滑移，降低近壁面纳米尺度范围液体的表观粘度，改善速度场和温度场的协同，有效降低流动阻力，以实现对纳米通道内液体流动的主动控制。研究以分子动力学模拟和理论分析为手段，模拟基于表面行波的纳米通道内液体的流动，分析和总结行波振幅、频率、壁面等因素对界面速度滑移、液体表观粘度的影响机制和规律，结合介观格子玻尔兹曼方法计算方腔内流场和温度的分布，建立表面行波/振动对它们影响的分析模型，以此为基础实现表面行波对液体在纳米通道内流动的主动控制。本项目为基于表面行波/振动进行微纳米系统中液体流动减阻/方腔中非牛顿流体传热强化的主动控制提供基本的机理、数据和模型基础。本项目在执行期间共发表6篇SCI期刊论文和3篇国际会议文章。