Investigation Into Thermal Conductivity And Elastic Properties Of Porous Foam Based On Voronoi Model

Porous foams is a new kind of functional and structural material composed with the solid skeleton and massive pores.Due to the pores,the material has the excellent features of low apparent density,high surface area,high porosity,high thermal conductivity,endurance of high temperature and corrosion,sound insulation,energy absorption,resistance of impacting and so on.With the development of science and technology,the excellent characteristics of porous foams can well satisfy the demand of miniaturization and lightweight.Compared with the conventional material,porous foams can better adapt to the development of the future.So it is very important to study the performances of porous foams.Compared with continuous media,porous foams contains a large number of pores with random distribution and size,which causes difficulties to predict the properties of porous foams.Considering the actual foam materials are mostly heterogeneous material,the properties of porous foams are related to the pore structure.Only the porosity is not enough to describe the pore structure of the real material.The affection of pore structure to the thermal conductivity and elastic mechanical properties has been studied through numerical simulation in this paper.The main research content includes:Based on 2-D Voronoi model in this paper,the randomness and porosity of models were defined to descript the pore structure parameters.By adjusting the deviation factor and edge width coefficient of the model changes the range of randomness and porosity.The thermal conductivity of 2-D Voronoi models were studied by MATLAB and ANSYS.The relatively thermal conductivity of porous foams were calculated.The influence of the randomness and porosity on the effective thermal conductivity of the model was analyzed,which shows that the randomness and porosity affect effective thermal conductivity.Results show that randomness increasing leads to effective thermal conductivity decreasing.From the simulations results of random models,it is pointed that the relative effective thermal conductivity of porous metal foam material can be expressed as power function of porosity and randomness.The elastic mechanical properties of 2-D Voronoi models were studied by MATLAB and ANSYS.The relatively elastic modulus of the porous foams were calculated.The results show that the relatively elastic modulus was effected by porosity and randomness.With the decreasing of the randomness,the relatively elastic modulus increasing.The prediction equation of relatively elastic modulus was proposed basing data.Based on the large results of thermal conductive and elastic mechanical numerical simulation,the effect of pore structure parameters on the properties of porous foam material is analyzed quantitatively,which provides reference experience for the property research and production preparation of porous foam material.