Thermal Performance Testing of Cryogenic Multilayer Insulation with Silk Net Spacers

Cryogenic Engineering Conference 2015

材料科学;物理学

Johnson, W.L.^1 ; Frank, D.J.^2 ; Nast, T.C.^2 ; Fesmire, J.E.^3

Glenn Research Center, Cleveland

OH

44135, United States^1

Lockheed Martin Advanced Technology Center, Palo Alto

CA

94304, United States^2

Cryogenics Test Laboratory, Kennedy Space Center, FL

32899, United States^3

关键词: Comprehensive testing;    Cryogenic insulations;    Multi-layer insulation;    Number of layers;    Performance correlation;    Performance improvements;    Thermal Performance;    Thermal performance testing;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/101/1/012018/pdf
DOI  :  10.1088/1757-899X/101/1/012018

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Early comprehensive testing of cryogenic multilayer insulation focused on the use of silk netting as a spacer material. Silk netting was used for multiple test campaigns that were designed to provide baseline thermal performance estimates for cryogenic insulation systems. As more focus was put on larger systems, the cost of silk netting became a deterrent and most aerospace insulation firms were using Dacron (or polyester) netting spacers by the early 1970s. In the midst of the switch away from silk netting there was no attempt to understand the difference between silk and polyester netting, though it was widely believed that the silk netting provided slightly better performance. Without any better reference for thermal performance data, the silk netting performance correlations continued to be used. In order to attempt to quantify the difference between the silk netting and polyester netting, a brief test program was developed. The silk netting material was obtained from Lockheed Martin and was tested on the Cryostat-100 instrument in three different configurations, 20 layers with both single and double netting and 10 layers with single netting only. The data show agreement within 15 - 30 % with the historical silk netting based correlations and show a substantial performance improvement when compared to previous testing performed using polyester netting and aluminum foil/fiberglass paper multilayer insulation. Additionally, the data further reinforce a recently observed trend that the heat flux is not directly proportional to the number of layers installed on a system.