Numerical Investigation of Effective Thermal Conductivity of Strut-Based Cellular Structures Designed by Spatial Voronoi Tessellation.

Minghao Zhang,Xuezheng Yue,Boyoung Hur,Shiyue Guo,Junteng Shang

doi:10.3390/ma14010138

Abstract

Porous materials possess light weight and excellent thermal insulation performance. For disordered porous structures, the number of seed points is an important design parameter which is closely related to the morphology and mean pore size of the structure. Based on the arrangement of points in three-dimensional space, seven kinds of structures were designed by spatial Voronoi tessellation in this paper. The effect of the number of seed points on effective thermal conductivity for Voronoi was studied. Numerical simulation was conducted to research the effects of structural porosity, filling material and structural orientation on the effective thermal conductivity and heat transfer characteristics. The results showed that the effective thermal conductivity is closely related to the porosity and the matrix material. Different number and arrangement of seed points make the structure have different anisotropic performance due to different thermal paths. In addition, required the least number of seed points was obtained for the designation of isotropic random Voronoi.

Highlights

Additive manufacturing (AM) constructs objects by stacking layers of materials [1,2].AM has high design freedom in three-dimensional space [3]
For a designated space with the same length, width and height, the points are arranged at the eight vertices of the cube and the center of the cube, and space was divided into nine polyhedrons by spatial Voronoi tessellation through these points, and the polyhedron at the center of the body was extracted and a certain thickness was added to the frame lines to obtain the Kelvin structures
If by reducing the number of seed points, we reduce the number of struts in the random Voronoi structure, the structure has thicker struts with the same porosity, which may improve the energy absorption and yield strength of the structure while not having a greater impact on the effective thermal conductivity of the structure

Summary

Introduction

Additive manufacturing (AM) constructs objects by stacking layers of materials [1,2].AM has high design freedom in three-dimensional space [3]. Additive manufacturing (AM) constructs objects by stacking layers of materials [1,2]. Objects with complex internal structures can be designed by parameterized constructive solid geometry (CSG) [4] or computer tomography (CT) [5] and fabricated by AM. Porous materials possess the characteristics of optimized distributions of pore size, mutative pore morphology, relative density, and high specific surface [12], porous material display excellent acoustic [13], biomedical [14], thermal conductivity [15] and fluid transfer [16] properties. The utility of additive manufacturing technologies makes the precise control of the arbitrary characteristics of porous materials and fidelity structural processing possible

Methods

Results

Discussion

Conclusion