BEM’s Analysis for Anisotropic Heat Conduction of Nearly Singular Integration

• Main Authors: Yi-Xiao Shi, 施宜孝
• Other Authors: Yui-Chuin Shiah
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/05943884128336074412

碩士 === 逢甲大學 === 航太與系統工程所 === 94 === The materials of industries application are usually combining with the structures of multi-thin layer. The common examples include layered composites, the assembly of flip chips in electronic packaging and sandwich structures…etc. Besides, the turbine of aerospace engineering in order to raise the temperature of using, it often spray a layer has heat insulation at the surface of turbine blade. If Single Crystal is used to be the base of turbine blade, then the composites are constructed by combining anisotropic materials such as a combination of anisotropic/isotropic materials. The goal of this project is to analyze the heat conduction between dissimilar anisotropic materials that are subjected to temperature change. The finite element method (FEM), finite difference method (FDM) and the boundary element method (BEM), are generally necessary for real applications in engineering practice. The FEM and FDM must according to the limitation of the aspect ratios of domain meshes. For this reason it will delimit too much mesh and add the burden of computer calculation. However, it is the feature of BEM to integral the boundary. Therefore, no matter how the thickness of thin layer is, it will not add the amount of mesh and good for analyzing these problems. By the practical point, it is important problem to analyze in industries that are related before. By the point of science, the BEM has been well recognized as a very efficient, alternative numerical tool. The feature of BEM is to dismember the layer of boundary, and don’t have to deal with the internal part of definition domain. The BEM can retrench operation and save space in the internal part, moreover, it imitates problems efficiently. However, when the BEM deal with these structures of multi-thin layer, it will produce the problem of near singular integration. The reason of the source point is very close to the integration element, and the integration function will severe shock at the vicinity of source point. Therefore, general numerical integration method can not obtain the correct data of integration. We take a efficient numerical method in these problem and apply it to analyze the heat conduction on the surface of structures of multi-thin layer and the internal part of temperature field. In the end of this project, we take this technique to analyze various problems of industries application and compare with the analysis of FEM.