基于真实表面的接触热阻模拟和分析

论文总字数：21178字

摘 要

本文首先利用MATLAB软件强大的数据处理功能，基于分形高度函数——W-M函数在三维笛卡尔坐标系下的表达式，获取了大量的表面形貌点数据。通过对这些数据进行计算，得到了表面轮廓算术平均偏差Ra。并研究了W-M函数中的分形参数与表面轮廓平均偏差Ra之间的关系。结果表明，随着分形维数D的增大和分形粗糙度G的减小，表面轮廓算术平均偏差Ra会逐渐减小，我们所得到的表面就越平整。

获得表面轮廓点数据后，导入到了UG软件中进行曲面和实体建模。基于点云数据，利用了UG 软件提供的多种曲面拟合方式，选用了最合适的“通过曲线网格”方法生成了最终的曲面模型，并通过拉伸、镜像等操作建立了最终的用于模拟、分析的实体模型。

最后使用有限元分析的方法，将实体模型导入ANSYS软件中进行了接触变形分析和热分析。分别获得了压力与表面变形量的变化关系以及界面温差与压力之间的变化关系，进而间接地获得了压力条件与表面接触热阻之间的变化关系。实验结果表明，随着压力的增大，粗糙表面间接触变形量也越大。接触表面间的接触热阻随压力的增大而减小。

关键词：粗糙表面，接触热阻，MATLAB，UG，ANSYS

The Simulation And Analysis of Thermal Contact Resistance Based On The Real Surface

02012228 Qin Wanxu

Supervised by Wang Jianli

Abstract：The topic of thermal contact resistance between two real rough surfaces which are contact with each other has been simulated and analyzed in this paper.A surface model and the corresponding solid model have been constructed based on the surface topography data that generated by the fractal theory,and been used to take the theoretical analysis and the simulation analysis.

At first,based on the fractal height function W-M function’s expression in a 3-dimensional Cartesian coordinates,a lot of surface topography data has been obtained by using the powerful software MATLAB,which provides powerful data processing functions to all the users.By calculating the data,I obtained the parameter Ra which called the arithmetical mean deviation of the profile that being used to represent the roughness of a surface.And I studied the relations between fractal properties and Ra.It indicated that by the increase of the parameter D which called fractal dimension and by the decrease of the parameter G which called fractal roughness,the roughness of a surface will decrease,the surface would be more flexible.

After generated all the surface topography data,these point data have been imported to the software UG to construct a surface model and generated a corresponding solid model.Based on the multiplied surface fitting methods that the software provided,the model has been built by using the most appropriate method”through curve grid”to generate the final solid model which been used in the very last simulation process and analysis process.

Finally, the model was imported to the analysis software ANSYS to take contact deformation and thermal analysis by using the finite element analysis method.By doing this,the relations between pressure and the deformation,the relations between pressure and temperature changes have been obtained respectively.And according to these relations,the relation between pressure and the thermal contact resistance has been modified indirectly.It indicated that by the increase of pressure,the deformation of the rough surfaces increases the same,while the thermal contact resistance decreases by the increasing of pressure.

Keywords：Rough Surface,Thermal Contact Resistance,MATLAB,UG,ANSYS

目 录

1.绪论 1

1. 1 课题背景、目的和意义 1

1.1.1接触热阻概述 1

1.1.2表面粗糙度概述 3

1.2 数值模型 3

1.2.1粗糙表面的表征 4

1.2.2 利用MATLAB软件表征粗糙表面 5

2 粗糙表面的接触模型 8

2.1 模型构建概述 8

2.2 利用UG软件进行曲面以及实体建模 8

2.2.1 使用“从点云”功能构建曲面 8

2.2.2 使用“通过曲线网格”功能构建曲面 9

2.3 利用曲面构建实体模型 10

3 模型分析及结果讨论 11

3.1 模型分析过程的建立 11

3.1.1 接触变形分析过程 11

3.1.2热分析过程 12

3.2 分析结果讨论 13

3.2.1 接触变形分析 13

3.2.2 接触传热分析 15

3.2.3 分形参数与表面粗糙度之间的关系 17

4 总结 18

4.1 毕设总结 18

4.2 毕设展望 18

致 谢 20

参考文献 21

基于真实表面的接触热阻的模拟和分析

1.绪论

1. 1 课题背景、目的和意义

传热学是研究由温差引起的热能量的传递规律的学科。同其他形式的能量传递一样，热能的传递与我们的生活有着密不可分的关系，是与我们人类的生存联系最密切的能量传递过程之一。热能的传递有三种基本的方式：热传导、热对流和热辐射。

热量传递过程是在两个具有温差的物体间自发进行的。在热量传递的过程中，同自然界其他的转移过程类似，都存在着一定的传递阻力。热传递过程中受到的阻碍作用称为热阻。而在接触传热中，由于接触表面间接触不良，在接触面上会产生对热量传递过程的阻碍作用，形成附加的热量传递阻力，我们将这种阻碍作用称之为接触热阻。

剩余内容已隐藏，请支付后下载全文，论文总字数：21178字