Experimental Studies On Shadow Shields For Thermal Protection Of Cryogenic Tanks In Space

Experiments were performed on multiple flat-disk shadow shields to determine the effects of shield spacing number, emissivity, lateral conductance, and targeting (high-emissivity coatings on annular rings of shields) on thermal performance. The experimental data, in general, agreed closely with an analytical model which assumed diffuse surfaces with nonuniform radiosity. A shadow-shield system for a hypothetical space vehicle was designed, scaled down, and tested. Results demonstrated: (1) a lightweight method of shield construction; (2) shield-support interactions: and (3) reduction of support heat leaks by shield location, attachment methods, and the use of high-emissivity coatings.

The National Bureau of Standards Boulder Laboratories at Boulder, Colorado once again served as the host for the 1972 Cryogenic Engineering Conference. For the Cryogenic Engineering Conference it was like coming horne, for it was at the NBS Boulder Laboratories that the Cryogenic Engineering Conference was first conceived and held m 1954m connection with the dedication ofthe NBS Boulder Laboratories by President Dwight D. Eisenhower. The Cryogenic Engineering Conference IS grateful for the continuing support that the National Bureau of Standards has gIVen over the years, and which was expanded on July 1, 1971 when the NBS Boulder Laboratories assumed the secretariat function of the Conference from the National Academy of Sciences. Because of common interests in heat transfer, the 1972 Cryogemc Engineering Conference worked with the 13th National Heat Transfer Conference to develop a joint program m heat transfer. A majority ofthe papers presented in this cooperative effort are incIuded m V olume 18 of the Advances zn Cryogenic Engineerzng through the kmd permission ofthe 13th NatIOnal Heat Transfer Conference and are acknowl edged accordingly.