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Thermal analysis of low layer density multilayer insulation test results
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Johnson, Wesley L. |
| Copyright Year | 2011 |
| Description | Investigation of the thermal performance of low layer density multilayer insulations is important for designing long-duration space exploration missions involving the storage of cryogenic propellants. Theoretical calculations show an analytical optimal layer density, as widely reported in the literature. However, the appropriate test data by which to evaluate these calculations have been only recently obtained. As part of a recent research project, NASA procured several multilayer insulation test coupons for calorimeter testing. These coupons were configured to allow for the layer density to be varied from 0.5 to 2.6 layer/mm. The coupon testing was completed using the cylindrical Cryostat-l00 apparatus by the Cryogenics Test Laboratory at Kennedy Space Center. The results show the properties of the insulation as a function of layer density for multiple points. Overlaying these new results with data from the literature reveals a minimum layer density; however, the value is higher than predicted. Additionally, the data show that the transition region between high vacuum and no vacuum is dependent on the spacing of the reflective layers. Historically this spacing has not been taken into account as thermal performance was calculated as a function of pressure and temperature only; however the recent testing shows that the data is dependent on the Knudsen number which takes into account pressure, temperature, and layer spacing. These results aid in the understanding of the performance parameters of MLI and help to complete the body of literature on the topic. |
| File Size | 1228180 |
| Page Count | 6 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20110014002 |
| Archival Resource Key | ark:/13960/t6n064h4x |
| Language | English |
| Publisher Date | 2011-06-13 |
| Access Restriction | Open |
| Subject Keyword | Fluid Mechanics And Thermodynamics Knudsen Flow Calorimeters Thermal Conductivity Thermal Analysis Multilayer Insulation Heat Flux Optimization Cryogenic Rocket Propellants Long Duration Space Flight Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
