부산대학교 도서관

The heat transfer characteristics of the wall formed by the aluminum extrusion and multi insulation material layers are studied experimentally and numerically. The experimental results show that the equivalent thermal conductivity of the wall does not depend on the temperature difference and its position regarding to the gravity direction. These results indicate that the roles of the natural convection and the radiation heat transfer in the aluminum extrusion are very weak, which are confirmed by the numerical results. The numerical results show that the aluminum extrusion formed by the aluminum tape with thickness less than 5% of the wall thickness transfers more than 99% of the total heat transferred through the combined layer. As resulting, a more uniform temperature distribution is obtained on the surface in contact with the air in the aluminum extrusion. The results suggest that the natural convection and heat radiation in the combined layer can be safely ignored.