The Experts below are selected from a list of 103809 Experts worldwide ranked by ideXlab platform
Hua Bao - One of the best experts on this subject based on the ideXlab platform.
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Effect of atmospheric water vapor on radiative Cooling Performance of different surfaces
Solar Energy, 2019Co-Authors: Chenyang Liu, B. X. Wang, Changying Zhao, Hua BaoAbstract:Abstract The sub-ambient clear sky daytime radiative Cooling has been achieved recently by applying advanced nanofabrication technologies, which attracted significant research attention in this area. However, there are also several researches which reported that radiative coolers with excellent thermal radiative spectrum failed to achieve sub-ambient radiative Cooling. To elucidate the difference, in this work, we perform a detailed investigation of ambient conditions, in particular, water vapor density, on the Performance of radiative coolers. We first present the details of how to estimate the Performance of radiative coolers under different water vapor concentration and simulate the transmittance and emitted radiation of atmosphere as well as the Cooling Performance of the ideal selective emitter, which finds the Cooling power decreases by 86.6 W/m2 with increasing total water vapor column. Furthermore, the Cooling Performance of an integrated photonic solar reflector and thermal emitter with atmospheric profiles in California and Hong Kong were calculated and compared with experiment result. To verify our calculation, nighttime on-site Cooling Performance of a reference film (Al foil) and two selective emitters (DESR-M and double-layer coating) was measured in several ambient conditions. Our research reveals how the ambient humidity affects the radiative Cooling Performance by both theoretical and experimental analysis and is important for the further application development of radiative coolers.
Chenyang Liu - One of the best experts on this subject based on the ideXlab platform.
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Effect of atmospheric water vapor on radiative Cooling Performance of different surfaces
Solar Energy, 2019Co-Authors: Chenyang Liu, B. X. Wang, Changying Zhao, Hua BaoAbstract:Abstract The sub-ambient clear sky daytime radiative Cooling has been achieved recently by applying advanced nanofabrication technologies, which attracted significant research attention in this area. However, there are also several researches which reported that radiative coolers with excellent thermal radiative spectrum failed to achieve sub-ambient radiative Cooling. To elucidate the difference, in this work, we perform a detailed investigation of ambient conditions, in particular, water vapor density, on the Performance of radiative coolers. We first present the details of how to estimate the Performance of radiative coolers under different water vapor concentration and simulate the transmittance and emitted radiation of atmosphere as well as the Cooling Performance of the ideal selective emitter, which finds the Cooling power decreases by 86.6 W/m2 with increasing total water vapor column. Furthermore, the Cooling Performance of an integrated photonic solar reflector and thermal emitter with atmospheric profiles in California and Hong Kong were calculated and compared with experiment result. To verify our calculation, nighttime on-site Cooling Performance of a reference film (Al foil) and two selective emitters (DESR-M and double-layer coating) was measured in several ambient conditions. Our research reveals how the ambient humidity affects the radiative Cooling Performance by both theoretical and experimental analysis and is important for the further application development of radiative coolers.
Warn-gyu Park - One of the best experts on this subject based on the ideXlab platform.
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MODELING THE Cooling Performance OF VORTEX TUBE USING A GENETIC ALGORITHM-BASED ARTIFICIAL NEURAL NETWORK
Thermal Science, 2016Co-Authors: Hassan Pouraria, Warn-gyu Park, Seyed Mostafa Kia, Bahman MehdizadehAbstract:In this study, artificial neural networks have been used to model the effects of four important parameters consist of the ratio of the length to diameter, the ratio of the cold outlet diameter to the tube diameter, inlet pressure, and cold mass fraction on the Cooling Performance of counter flow vortex tube. In this approach, experimental data have been used to train and validate the neural network model with MATLAB software. Also, genetic algorithm has been used to find the optimal network architecture. In this model, temperature drop at the cold outlet has been considered as the Cooling Performance of the vortex tube. Based on experimental data, Cooling Performance of the vortex tube has been predicted by four inlet parameters. The results of this study indicate that the genetic algorithm-based artificial neural network model is capable of predicting the Cooling Performance of vortex tube in a wide operating range and with satisfactory precision.
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NUMERICAL INVESTIGATION ON Cooling Performance OF RANQUE-HILSCH VORTEX TUBE
Thermal Science, 2014Co-Authors: Hassan Pouraria, Warn-gyu ParkAbstract:A Ranque-Hilsch vortex tube (RHVT) is a mechanical device that separates a high pressure gas stream into low pressure hot and cold streams. In this study, four different two equation turbulence models namely the standard k-?, RNG k-?, Realizable k-? and standard k-? models were compared to identify the appropriate turbulence model for studying the energy separation effect in a RHVT. Comparison between the numerical and experimental results indicates that the standard k-? model is better than other models in predicting the energy separation phenomenon. The distributions of temperature, pressure, and components of velocity have been obtained in order to understand the flow behavior inside the tube. The effect of cold outlet diameter on temperature drop and refrigeration capacity was studied. The effect of cold mass fraction on the movement of stagnation point and refrigeration capacity has been investigated. Moreover, the feasibility of improving the Cooling Performance of vortex tube using the Cooling system was investigated. The present numerical results revealed that using the Cooling system, the net energy transfer rate from cold inner region to the hot peripheral region increases, thereby improving the Cooling Performance of the device.
A. Androutsopoulos - One of the best experts on this subject based on the ideXlab platform.
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The Cooling Performance of a radiator based roof component
Solar Energy, 2006Co-Authors: A. Dimoudi, A. AndroutsopoulosAbstract:Energy conservation in buildings is becoming an issue of great importance. Space Cooling is getting important in most countries and different techniques have been developed one of which is radiative Cooling. A prototype roof component, exploiting radiative Cooling, was built and tested in the outdoor test facilities of the Centre of Renewable Energy Sources in Greece. The component comprises a radiator, which is utilizing water as the fluid medium and its Cooling Performance was investigated. This paper presents the construction of the component, the experimental set-up and the results taken during the monitoring procedure.
B. X. Wang - One of the best experts on this subject based on the ideXlab platform.
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Effect of atmospheric water vapor on radiative Cooling Performance of different surfaces
Solar Energy, 2019Co-Authors: Chenyang Liu, B. X. Wang, Changying Zhao, Hua BaoAbstract:Abstract The sub-ambient clear sky daytime radiative Cooling has been achieved recently by applying advanced nanofabrication technologies, which attracted significant research attention in this area. However, there are also several researches which reported that radiative coolers with excellent thermal radiative spectrum failed to achieve sub-ambient radiative Cooling. To elucidate the difference, in this work, we perform a detailed investigation of ambient conditions, in particular, water vapor density, on the Performance of radiative coolers. We first present the details of how to estimate the Performance of radiative coolers under different water vapor concentration and simulate the transmittance and emitted radiation of atmosphere as well as the Cooling Performance of the ideal selective emitter, which finds the Cooling power decreases by 86.6 W/m2 with increasing total water vapor column. Furthermore, the Cooling Performance of an integrated photonic solar reflector and thermal emitter with atmospheric profiles in California and Hong Kong were calculated and compared with experiment result. To verify our calculation, nighttime on-site Cooling Performance of a reference film (Al foil) and two selective emitters (DESR-M and double-layer coating) was measured in several ambient conditions. Our research reveals how the ambient humidity affects the radiative Cooling Performance by both theoretical and experimental analysis and is important for the further application development of radiative coolers.