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ISSN Online: 2379-1748

ISBN Flash Drive: 978-1-56700-431-1

ISBN Online: 978-1-56700-430-4

First Thermal and Fluids Engineering Summer Conference
August, 9-12, 2015 , New York City, USA

NET RADIATIVE HEAT EXCHANGE OF AN ORIGAMI-INSPIRED, VARIABLE EMISSIVITY SURFACE

Get access (open in a dialog) pages 187-197
DOI: 10.1615/TFESC1.asp.012731

Abstract

A V-grooved, origami surface may be used to control apparent emissivity and absorptivity dynamically through control of the cavity effect with linear actuation. However, for a fixed material size, the projected surface area decreases as the apparent emissivity increases. A model was developed to examine the total emission of a V-grooved surface as a function of cavity angle for both diffuse and collimated irradiation. The maximum rate of net radiative heat exchange exists at a cavity angle of 180° (unfolded) for diffuse irradiation and at or above 120° for collimated irradiation at any intrinsic emissivity value. The net radiative heat exchange for diffuse irradiation increases monotonically with increasing cavity angle; collimated irradiation normal to the projected area results in a general increase in net radiative heat exchange with increasing cavity angle but with local minimums observed at some cavity angles due to a finite, whole number of reflections. Experimental data to indicate the ability to control surface temperature with cavity angle was also collected using a vacuum chamber and Joule heating of a folded surface.