Effective Thermal Conductivity of High Temperature Insulations for Reusable Launch Vehicles

Abstract

An experimental apparatus was designed to measure the effective thermal conductivity of various high temperature insulations subject to large temperature gradients representative of typical launch vehicle reentry aerodynamic heating conditions. The insulation sample cold side was maintained around room temperature, while the hot side was heated to temperatures as high as 1800°F. The environmental pressure was varied from 1 x 10 -4 to 760 torr. All the measurements were performed in a dry gaseous nitrogen environment. The effective thermal conductivity of the following insulation samples were measured: Saffilä at 1.5, 3, 6 lb/ft 3 , Q-Fiberä felt at 3, 6 lb/ft 3 , Cerachromeä at 6, 12 lb/ft 3 , and three multi-layer insulation configurations at 1.5 and 3 lb/ft 3 .. Introduction Metallic and refractory-composite thermal protection systems are being considered for a new generation of reusable launch vehicles (RLV). The main function of the thermal protection system (TPS) is to...