Modulation of apparent optical properties using arrayed mesoscale structures

Journal Article · 05 June 2022 · Journal of Quantitative Spectroscopy and Radiative Transfer

DOI: https://doi.org/10.1016/j.jqsrt.2022.108280 · OSTI ID:2422331

Simeroth, David L.  ^[1]; Kottke, Peter A. ^[2]; Kucuktas, Onur A. ^[2]; Fedorov, Andrei G.  ^[2]

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1. Georgia Institute of Technology, Atlanta, GA (United States); OSTI
2. Georgia Institute of Technology, Atlanta, GA (United States)

In this study, a method for using arrays of mesoscale structures to modify the apparent optical properties of an opaque composite surface has been theoretically demonstrated to both raise and lower the apparent emissivity as compared to the intrinsic properties of the constitutive materials. For design problems where thermomechanical and optical material properties are both of importance, mesoscale surface structuring can greatly expand the design space. Analysis via the net radiosity method herein illustrates the ability to achieve a wide range of spectral apparent optical properties. Notably, a hexagonal array of spheres on a planar surface can raise the apparent emissivity of a planar surface by 50%. Conversely, a hexagonal enclosure of reradiating surfaces, realized by thin adiabatic walls, can reduce the apparent emissivity of a blackbody by half. As this method of modifying apparent optical properties utilizes structures much larger than the wavelengths of interest, the relationship between intrinsic planar emissivity, geometry, and apparent emissivity can be computed semi-analytically at low computational expense. Passive solar cooling, thermophotovoltaic cells, aerodynamic surfaces exposed to intense heating, and solar absorbers are presented as case studies that could benefit from the use of mesoscale structures on opaque surfaces to modify the apparent optical properties.

• Research Organization: Georgia Institute of Technology, Atlanta, GA (United States)
• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• Grant/Contract Number: AR0001207
• OSTI ID: 2422331
• Journal Information: Journal of Quantitative Spectroscopy and Radiative Transfer, Journal Name: Journal of Quantitative Spectroscopy and Radiative Transfer Journal Issue: C Vol. 290; ISSN 0022-4073
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English