Speaker
Description
Managing energy consumption and thermal radiation is crucial for environmental sustainability. Passive radiative cooling (PRC) has recently emerged as an effective method for reducing environmental energy density without external power input. This study investigated three wavelength ranges (2.5–5 μm, 8–13 μm, and 16–27 μm) to optimize cooling performance. Optical and electrical properties were obtained using density functional theory (DFT). A honeycomb metamaterial structure was designed as a spectrally selective emitter using the Finite Element Method (FEM). The effects of geometric parameters on absorbance and emissivity were analyzed. The optimized structure achieved a daytime net cooling power of 150.4 W/m² under 994 W/m² solar irradiation and 198 W/m² at night. Equilibrium temperatures reached 256 K during daytime and 244 K at night at an ambient temperature of 300 K. The cooler maintained sub-ambient temperatures even with parasitic convection and conduction losses. In addition, the structure showed polarization independence and high emissivity across incidence angles from 0° to 75°. This work supports global warming mitigation and environmental sustainability.
Keywords: Environmental protection, Metamaterial, Solar irradiation, Selective emissivity, Atmospheric window, Radiative cooling.
| Topic Area | Structural Safety, Integrity Management and Life Extension of Structures |
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