Adaptive Net Radiative Heat Transfer and Thermal Management With Origami-Structured Surfaces

Thermal performance of dynamic, origami‐inspired geometries: An experimental study

“…As a result, the cavity effect decreases as radiation may escape without scattering inside the cavity. A similar effect can be seen for the Miura Ori (1) fold as the apparent absorptivity of the Miura Ori (1) increased with increasing compression which is in agreement with numerical results by Iverson et al 27 Experimental results of this study and numerical data from literature 27 prove the cavity effect of radiative reabsorption and entrapment, leading to a higher apparent absorptivity than a flat case. For the Miura Ori (2) fold (which is a variation of the Miura Ori (1) but oriented differently), except for the 800 W case, the same analysis could be conducted that also agrees with Iverson et al 27 Miura Ori results.…”

“…When the time series of temperature for the heating stage was investigated (sample data in Figure 5), it was observed that geometries with deeper cavities generally required the longest time to reach steady-state conditions, which would suggest smaller heat flux values. For instance, examining the case of 1600 W for the Miura Ori (2) pattern at 0.35 and 0.15 m compression shows that for the 0.35 m case, the average time to steady-state cooling was 80 s, and for the 0.15 m case the time to steady-state on average was 153 s. This fine balance between apparent absorptivity and compression was also reported by Iverson et al 27 For W-fold geometry, a numerical study conducted by Iverson et al 27 has revealed that the apparent absorptivity of this geometry decreases with increasing compression approximately 90°-120°(which are equivalent to 0.32 and 0.39 m compression, respectively). A similar trend (reduction in the apparent absorptivity from 0.45 to 0.35 m) can be identified for the W-fold in Figure 8A.…”

“…This outcome was also reported by other researchers. 27,28 The Miura Ori (1) fold best showed this trend, whereas the W-fold and Miura Ori (2) patterns generally supported these findings. For 800 W, the increase in apparent absorptivity between 0.45 and 0.15 m was found to be 16.3%, 79.6%, and 68.4%, for the W-fold, Miura Ori (1), and Miura Ori (2), respectively.…”

“…Geometry and compression have less effect on surface temperature for higher radiation inputs as smaller temperature increases were observed. The W-fold is one of the most studied geometries 27,28 and the temperature is expected to continue to increase, as it has from 0.45 to 0.25 m for the 1600 and 2400 W trials. Due to the nature of aluminum foil, being easily deformed, and the nature of the W-fold having long folded columns, it is likely that the structure became less rigid/straight as the geometry was compressed.…”

Total Hemispherical Apparent Radiative Properties of the Infinite V-Groove with Diffuse Reflection

“…Dynamic control of radiative surface properties enables optimization of thermal management systems for spacecraft, radiative cooling systems and other applications [1][2][3]. Various methods of altering the absorption or emission from a surface have been investigated [4][5][6].…”