0
Research Papers

Modeling Transmission Effects on Multilayer Insulation

[+] Author and Article Information
Robert C. Youngquist

The KSC Applied Physics Laboratory (NE-L5),
National Aeronautics and Space Administration,
Kennedy Space Center, FL 32899
e-mail: robert.c.youngquist@nasa.gov

Mark A. Nurge

The KSC Applied Physics Laboratory (NE-L5),
National Aeronautics and Space Administration,
Kennedy Space Center, FL 32899
e-mail: mark.a.nurge@nasa.gov

Wesley L. Johnson

Glenn Research Center,
National Aeronautics and Space Administration,
21000 Brookpark Road, Mail Stop: 301-3,
Cleveland, OH 44135
e-mail: wesley.l.johnson@nasa.gov

Stanley O. Starr

The KSC Applied Physics Laboratory (NE-L5),
National Aeronautics and Space Administration,
Kennedy Space Center, FL 32899
e-mail: stanley.o.starr@nasa.gov

SBIR.gov.

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS. Manuscript received April 3, 2014; final manuscript received August 26, 2014; published online January 28, 2015. Assoc. Editor: Ranganathan Kumar.

This material is declared a work of the US Government and is not subject to copyright protection in the United States. Approved for public release; distribution is unlimited.

J. Thermal Sci. Eng. Appl 7(2), 021007 (Jun 01, 2015) (7 pages) Paper No: TSEA-14-1063; doi: 10.1115/1.4028570 History: Received April 03, 2014; Revised August 26, 2014; Online January 28, 2015

Multilayer insulation (MLI), commonly used in cryogenics, is typically composed of many layers of thin polymer sheets each coated with a thin film of highly reflective metal. The primary purpose of this insulation is to block radiative energy transfer. However, at very low temperatures where blackbody radiation occurs at long wavelengths, some energy may be transmitted through these layers, degrading the performance of the insulation. Traditional modeling techniques assume that the films are opaque and are not easily extended to include radiative transmission through the layers. In order to model the effect of wavelength dependent transmission on the thermal performance of MLI, an L1-norm energy vector is defined and combined with a square energy distribution matrix. The key here is that the energy distribution matrix describes one time step of the radiation—one set of reflections, transmissions, and absorptions—and since this matrix is square, it can be easily raised to a large power, describing the final state of the system quickly. This approach removes the need to track every reflected and transmitted radiation element, but instead determines the eventual location where the thermal radiation energy is deposited. This method can be generalized to model dependence of the reflection and transmission of the radiation on wavelength or angle of propagation, to include thermal conduction effects, and to model transient behavior. The results of this work predict the degree of transmission dependent degradation expected to be seen when using state-of-the-art MLI in low temperature cryogenic systems.

FIGURES IN THIS ARTICLE
<>
Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

A cold and a hot surface face each other with a single sheet of metalized insulation between them. Radiation emerges from each surface and reflects back and forth depositing energy onto each surface with each reflection.

Grahic Jump Location
Fig. 2

This graph shows the power transfer between a hot surface at 300 K and a cold surface with a single layer of metalized insulation between them. The results are given for four different cases. One corresponds to the case of no transmission through the metalized layer. The remaining three allow transmission corresponding to metalized film thicknesses of 35 nm, 60 nm, and 100 nm per layer side.

Grahic Jump Location
Fig. 5

This graph shows the power density ratio versus the hot side temperature for effective metalized film thicknesses of 35 nm, 60 nm, and 100 nm per layer side. In each case, five layers of metalized insulation are located between a cold surface at 4 K and a hot surface with varying temperature. The power density ratio is computed by taking the power transfer for each metalized film thickness and dividing by the power transfer for the ideal case of no transmission.

Grahic Jump Location
Fig. 3

This graph shows the power density ratio versus the hot side temperature for metalized film thicknesses of 35 nm, 60 nm, and 100 nm per side. In each case, a single layer of metalized insulation is located between a cold surface at 4 K and a hot surface with varying temperature. The power density ratio is computed by taking the power transfer for each metalized film thickness and dividing by the power transfer for the ideal case of no transmission.

Grahic Jump Location
Fig. 4

This graph shows the power transfer between a hot surface at 300 K and a cold surface with five layers of metalized insulation between them. The results are given for four different cases. One corresponds to the case of no transmission through the metalized layer. The remaining three allow transmission corresponding to metalized film thicknesses of 35 nm, 60 nm, and 100 nm per layer side.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In