Improvement of isothermal characteristic of isothermal chamber by filling with graded copper foam

Abstract

Due to the isotropy and high thermal conductivity of metal foam, a novel idea of isothermal chamber filled with graded copper foam (GCF) is developed to improve the isothermal characteristic of isothermal chamber. Firstly, an analytical effective thermal conductivity (ETC) prediction model of metal foam is proposed, with relative root-mean-square error (RRMSE) is 6.90%, which has higher ETC prediction accuracy than the semi-empirical models in the literatures. Secondly, the conventional porous random fiber bundle is replaced by the copper foam as the filler material to improve the isothermal characteristic, and this more accurate ETC prediction model of metal foam is used in the numerical simulation of the discharge process to determine the isothermal characteristic of isothermal chamber filled with homogeneous copper foam (HCF). Experiments are conducted to verify the results of simulation. Thirdly, the graded filling method is adopted to form an isothermal chamber filled with GCF, which enhance the heat transfer efficiency and further improve the isothermal characteristic. The results show that, compared with the conventional isothermal chamber filled with homogeneous porous random fiber bundle, the isothermal characteristic of the isothermal chamber filled with GCF is improved by 32.7%.