Scalable thermochromic smart windows with passive radiative cooling regulation

Here, we address the turbulent dynamics of the gravitational instability in accretion disks, retaining both radiative cooling and irradiation. Due to radiative cooling, the disk is unstable for all values of the Toomre parameter, and an accurate estimate of the maximum growth rate is derived analytically. A detailed study of the turbulent spectra shows a rapid decay with an azimuthal wave number stronger than ky−3, whereas the spectrum is more broad in the radial direction and shows a scaling in the range kx−3 to kx−2. The radial component of the radial velocity profile consists of a superposition of shocks of different heights, and is similar to that found in Burgers’ turbulence. Assuming saturation occurs through nonlinear wave steepening leading to shock formation, we developed a mixing-length model in which the typical length scale is related to the average radial distance between shocks. Furthermore, since the numerical simulations show that linear drive is necessary in order to sustain turbulence, we used the growth rate of the most unstable mode to estimate the typical timescale. The mixing-length model that was obtained agrees well with numerical simulations. The model gives an analytic expression for the turbulent viscosity as a function of the Toomre parameter and cooling time. It predicts that relevant values of α = 10−3 can be obtained in disks that have a Toomre parameter as high as Q ≈ 10.

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LIGHT TRANSPORT ANALYSIS OF SMART WINDOWS FOR SOLAR ENERGY HARVESTING

Proceedings of RAD-13. Proceedings of the 7th International Symposium on Radiative Transfer, June 2-8, 2013, Kusadasi, Turkey ◽

10.1615/ichmt.2013.intsympradtransf.220 ◽

2013 ◽

Author(s):

Onur Taylan ◽

Thomas E. Murphy ◽

Halil Berberoglu

Keyword(s):

Energy Harvesting ◽

Solar Energy ◽

Light Transport ◽

Smart Windows ◽

Solar Energy Harvesting ◽

Transport Analysis

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A SIMPLIFIED PANEL FOR BOTH DIURNAL PHOTOVOLTAIC CONVERSION AND NOCTURNAL RADIATIVE COOLING

10.1615/ihtc16.nee.022440 ◽

2018 ◽

Author(s):

Bin Zhao ◽

Mingke Hu ◽

Xianze Ao ◽

Gang Pei

Keyword(s):

Radiative Cooling ◽

Photovoltaic Conversion

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ENERGY SAVING ANALYSIS OF A METAMATERIAL BASED RADIATIVE COOLING SYSTEM FOR LOW-RISE RESIDENTIAL BUILDINGS BY INTEGRATING WITH RADIANT FLOOR

10.1615/tfec2018.nbe.022313 ◽

2018 ◽

Cited By ~ 1

Author(s):

Jinchao Yuan ◽

Kai Zhang ◽

Dongliang Zhao ◽

Xiaobo Yin ◽

Ronggui Yang ◽

...

Keyword(s):

Energy Saving ◽

Cooling System ◽

Residential Buildings ◽

Radiative Cooling

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Yttrium Oxyhydrides for Photochromic Applications: Correlating Composition and Optical Response

10.26434/chemrxiv.7034585 ◽

2018 ◽

Author(s):

Dmitrii Moldarev ◽

Elbruz M. Baba ◽

Marcos V. Moro ◽

Chang C. You ◽

Smagul Zh. Karazhanov ◽

...

Keyword(s):

Medical Devices ◽

Ternary Diagram ◽

Optical And Electrical Properties ◽

Ambient Conditions ◽

Elastic Recoil ◽

Elastic Recoil Detection Analysis ◽

Photochromic Properties ◽

Smart Windows ◽

Elastic Recoil Detection ◽

Detection Analysis

It has been recently demonstrated that yttrium oxyhydride(YHO) films can exhibit reversible photochromic properties when exposed to illumination at ambient conditions. This switchable optical propertyenables their utilization in many technological applications, such as smart windows, sensors, goggles, medical devices, etc. However, how the composition of the films affects their optical properties is not fully clear and therefore demands a straightforward investigation. In this work, the composition of YHO films manufactured by reactive magnetron sputtering under different conditions is deduced in a ternary diagram from Time-of-Flight Elastic Recoil Detection Analysis (ToF-ERDA). The results suggest that stable compounds are formed with a specificchemical formula – YH<sub>2-δ</sub>O<sub>δ</sub>. In addition, optical and electrical properties of the films are investigated, and a correlation with their compositions is established. The corresponding photochromic response is found in a specific oxygen concentration range (0.45 < δ < 1.5) with maximum and minimum of magnitude on the lower and higher border, respectively.

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