Theoretical and Numerical Characterization of the Thermal Physical Properties of Carbon Ceramic Material

Abstract

Abstract.The article presents models representative volume element of the porous carbon-ceramic material. Simulating of heat transfer process in a representative volume element is carried out and thermal characteristics of material are determined by a settlement way. Influence of characteristics of material structure -its porosity and type of reinforcement -on values of heat-physical characteristics is investigated. It is shown that in the field of high temperatures (more than 1500 T) the defining role in the course of heat transfer in high-porous (Р> 40%) materials belongs to radiation heat exchange in a pores.

Theoretical and numerical characterization of the thermal conductivity of carbon ceramic material from realistic microscale imaging

“…It was assumed that all the fibres had equal diameter. The study in [5] demonstrated the evident relationship of the effective and molecular thermal conductivity from the temperature and porosity.…”

“…3-4) are presented. It is evident that the material structure is significantly different from the models used in [5]. Fig 3. 3D structure model of a porous CCCM sample area, obtained with X-ray micro-CT scanning.…”

“…Moreover, the experiments can determine only the so-called effective thermal conductivity coefficient, which estimates the total heat transfer including both conductive heat transfer along the reinforcement and radiative heat transfer in the pores. The conductive heat transfer is described by means of the molecular thermal conductivity coefficient [5]. Therefore, at this stage of research it appears reasonable to perform the theoretical and numerical estimation of the porous CCCM thermal conductivity separating the heat transfer constituents.…”

“…The heat conductivity analysis of the porous CCCM (with 1000-2000 kg/m 3 density) accounting for the radiative heat transfer in the pores is conducted in [5].…”

“…In order to determine the effective thermal conductivity coefficient of the porous CCCM an approach similar to [5] was used. First, a finite-element model of a representative volume element was created in the Siemens NX software package (Fig.…”