CHARACTERIZATION OF THERMOPHYSICAL PROPERTIES OF LAYERED PERFORATED ALUMINUM AND ARAMID CLOTH

Sandia National Laboratories has developed and tested a package design for air transport of plutonium that can survive a “worst-case” aircraft crash. This design utilizes layered perforated aluminum metal and aramid cloth for the primary structural and thermal protection of the contents during a hypothetical aircraft accident. The thermophysical properties of these materials were characterized in order to have a better understanding of the thermal behavior of perforated aluminum combined with KEVLAR® when used as an overpack for a transportation container in both the normal and accident conditions of transport. Samples of perforated aluminum with different percent of crush were prepared and their thermal conductivity (k) at different temperatures, both perpendicular to the plane as well as parallel to the plane, were measured. The specific heat (Cp) of the samples was also measured. The results obtained show the relationship between the thermal conductivity and the percent of crush. Equations of the effective thermal conductivity as a function of percent crush were developed for both the in-plane and through-plane directions. Plots of density and thermal conductivity as a function of percent crush are presented in this paper.