Fast Numerical Algorithm For Heat Dissipation Analysis Of Inhomogeneous Metallic Honeycomb Materials

Metallic honeycomb material, which is also called2D lattice material, not only has high specific stiffness and high specific strength but also has outstanding heat dissipation performance, so it is an important heat dissipation material and structure. Metallic honeycomb is easy to design, so its micro structure can be designed to meet different needs, such as optimum heat dissipation performance. Current heat dissipation analysis and design are mostly for homogeneous honeycomb, mainly focused on the selection of topological type (e.g.:quadrilateral, triangle, hexogen and so on). But a lot of natural and practical projects hint us that inhomogeneous material has better properties, and the key point of optimum heat dissipation design for metallic honeycomb material is an effective analysis method. Present fast numerical algorithm, which is based on the assumption that all fluid within a cross-section is isothermal, is only for homogeneous honeycomb and cannot be applied for inhomogeneous honeycomb. Thus, it has great significance to research and establish an accurate and effective analysis method for the prediction of inhomogeneous honeycomb’s heat dissipation efficiency.In this paper, fast numerical algorithm for the heat dissipation analysis of inhomogeneous honeycomb material is researched. The effect of the assumption, which is that all fluid within a cross-section is isothermal, on the heat dissipation efficiency analysis of metallic honeycomb is analyzed. According to this analysis, a new improved fast numerical algorithm is presented. Based on this improved algorithm, optimum heat dissipation efficiency design of inhomogeneous quadrilateral honeycomb is undertaken. The specific works are as follows:A fast numerical algorithm for heat dissipation analysis of inhomogeneous metallic honeycomb materials. Based on the present fast numerical algorithm (Acta Materiae Compositae Sinica,2008,25(3):197-201), which is developed by our group and only for the heat dissipation analysis of homogeneous metallic honeycomb material, it is further developed into the application of inhomogeneous metallic honeycomb. A new fast numerical algorithm for heat dissipation analysis of inhomogeneous metallic honeycomb materials is provided. In which, the assumption that all fluid within a cross-section is isothermal is retained, and the influence of cell’s hydraulic diameter on the convective heat transfer coefficient is considered. Because the new fast numerical algorithm can take different cell’s convective heat transfer property into consideration, it can be applied in any shape of inhomogeneous honeycomb. Through analysis of specific case, it is found that this new algorithm can be used for the analysis of inhomogeneous honeycomb but it has big differences. For inhomogeneous honeycomb, the temperature’s gradient distribution of fluid within a cross-section is severe, but the new algorithm regards all fluid within a cross-section as isothermal, so this ignorance of temperature’s gradient distribution of fluid brings great differencesAn improved algorithm which can consider the temperature distribution of fluid within a cross-section. According to the deficiency of last algorithm, an improved algorithm is presented. To reflect the temperature distribution of fluid within a cross-section, the temperature of fluid in every cell is supposed to be isothermal. Based on this assumption, new algorithm formulations are given, and the validity and applicability of this improved algorithm is proved through specific examples. Compared with finite volume method, the calculation speed can be increased by2orders of magnitude, and the improved algorithm can reflect the temperature distribution of fluid within a cross-section correctly. By extracting the temperature distribution of fluid and solid within a cross-section, the influence of fluid’s temperature distribution on the analysis of honeycomb’s heat dissipation is discussed.Optimization design of inhomogeneous quadrilateral honeycomb for heat dissipation. Using the improved algorithm, optimization design of inhomogeneous quadrilateral honeycomb for heat dissipation is undertaken. Several design proposals are attempted in this paper, and the influence of these proposals on structure’s heat dissipation efficiency is discussed as well as the reason for this influence. According to some conclusions obtained through above analysis, a high performance inhomogeneous quadrilateral honeycomb is given, which has better heat dissipation efficiency than homogeneous quadrilateral honeycomb.