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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Heat Transfer in Vacuum Thermal Insulation of Space Vehicles: An Experimental Estimate vs Theoretical Prediction

Get access (open in a dialog) DOI: 10.1615/IHTC15.rad.009822
pages 7237-7250

Sinopsis

The study is motivated by necessity to confirm or disprove the main assumption of a theoretical model developed recently by the authors. The theoretical model is based on neglecting possible near-field effects in heat transfer between closely spaced aluminum foils used in the multilayer vacuum thermal insulation (MLI) of modern high-weight spacecrafts. Highly porous fibrous spacers prevent a direct contact between the aluminum screens but the thickness of these spacers is very small and do not exclude the near-field interaction. It is well known that a special feature of the near-field heat transfer is a great increase in heat flux between two metal layers. An expected increase in heat flux in several orders of magnitude due to near-field electromagnetic interaction makes justified the use of an experimental procedure which is not very accurate but gives an estimate of the heat flux through the MLI in a thermo-vacuum installation used to model the space conditions. A sample of real MLI of the BP-Colombo satellite (ESA) is used in the laboratory experiments. A comparison of the computational results and the experimental data confirms that there are no significant near-field effects in MLI in the space vacuum and there is no contradiction between the previously developed far-field model of radiative transfer in MLI and the experimental estimates.