Control of Net Radiative Heat Transfer With a Variable-Emissivity Accordion Tessellation

Keywords

origami, variable emissivity, net surface heat transfer, accordion, V-groove

Abstract

Origami tessellations have been proposed as a mechanism for control of radiative heat transfer through the use of the cavity effect. This work explores the impact of a changing projected surface area and varying apparent radiative properties on the net radiative heat transfer of an accordion fold comprised of V-grooves. The net radiative heat transfer of an accordion tessellation is obtained by a thermal energy balance at the cavity openings with radiative properties of the cavities given as a function of various cavity parameters. Results of the analytical model are experimentally confirmed. An accordion tessellation, constructed of stainless-steel shim stock, is positioned to achieve a specified fold angle and placed in a vacuum environment while heated by Joule heating. A thermal camera records the apparent temperature of the cavity openings for various fold angles. Results are compared to apparent temperatures predicted with the analytical model. Analytically and experimentally obtained temperatures agree within 5% and all measurements fall within experimental uncertainty. For diffusely irradiated surfaces, the decrease in projected surface area dominates, causing a continuous decrease in net radiative heat transfer for a collapsing accordion fold. Highly reflective specular surfaces exposed to diffuse irradiation experience large turn-down ratios (7.5× reduction in heat transfer) in the small angle ranges. Specular surfaces exposed to collimated irradiation achieve a turn down ratio of 3.35 between V-groove angles of 120 deg and 150 deg. The approach outlined here may be extended to modeling the net radiative heat transfer for other origami tessellations.

Original Publication Citation

Mulford, R. B., Dwivedi, V. H., Jones, M. R., and Iverson, B. D., 2019, "Control of net radiation heat transfer of a variable emissivity accordion tessellation," Journal of Heat Transfer, Vol. 141, pp. 032702. DOI: 10.1115/1.4042442

Document Type

Peer-Reviewed Article

Publication Date

2019-3

Permanent URL

http://hdl.lib.byu.edu/1877/6492

Publisher

Journal of Heat Transfer

Language

English

College

Ira A. Fulton College of Engineering and Technology

Department

Mechanical Engineering

University Standing at Time of Publication

Associate Professor

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