Numerical investigation on the thermal performance of double glazing air flow window with integrated blinds
RENEWABLE ENERGY
Authors: Movassag, Sirous Zeyninejad; Zamzamian, Kamiar
Abstract
In this paper, double glazing air flow window with integrated blinds (IBAFW) numerically is investigated and the only winter indoor mode is considered for further assessments. To validate the CFD model, the results are compared with the experimental data found in the literature. For the thermal performance evaluation, total heat gain (q(gain)) which represents the heat gained by ventilation (q(adv))and heat gained by the back glass (q(bg)) was considered. As a part of the study, effect of the structural parameters such as tilt angle of blinds, gap size and the areas of inlet and outlet vents on the thermal performance of IBAFW were studied. The results showed that by changing the blinds tilt angle from 30 degrees to 60 degrees, total heat gain increased approximately 132-146% in different solar radiation ranges. It is also concluded that increasing the gap size increased the total heat gain approximately 106%. However, the increase of outlet vent area effected reversely and resulted in decreasing the thermal efficiency by 127%. Additionally, thermal performance comparison between IBAFW and conventional solar ventilated window (SOLVENT) was carried out. The results showed that the IBAFW reveals approximately 330-580% higher thermal efficiency comparing to the SOLVENT systems. (C) 2019 Elsevier Ltd. All rights reserved.
Ge3P2: New viable two-dimensional semiconductors with ultrahigh carrier mobility
APPLIED SURFACE SCIENCE
Authors: Li, Zhenqing; Shi, Xizhi; He, Chaoyu; Ouyang, Tao; Li, Jin; Zhang, Chunxiao; Zhang, Sifan; Tang, Chao; Romer, Rudolf A.; Zhong, Jianxin
Abstract
The two-dimensional germanium phosphide (GeP) and germanium arsenide (GeAs and GeAs2) were recently realized (Adv. Mater. 2018, 30, 1706771; Adv. Funct. Mater. 2018, 28, 1707379; Adv. Mater. 2018, 30, 1705934; Adv. Mater. 2018, 1804541) to extend the fast growing 2D materials family. In this work, other possible 2D GexPy structures are systematically investigated through the combination of the stochastic search strategy (RG(2)) and density functional theory. The RG(2) code repeats all the previously proposed GexPy layers and provides two new Ge3P2 structures (Cmmm-Ge3P2 and P4/mbm-Ge3P2). The calculated formation enthalpy shows that Cmmm-Ge3P2 and P4/mbm-Ge3P2 are two new viable phases locating at the convex hull. They are further confirmed to be dynamically and mechanically stable semiconductors with indirect band gaps of 1.62 eV and 1.89 eV, respectively, and their electronic properties can be effectively modulated by uniaxial strains. The evaluated electron mobilities of Cmmm-Ge3P2 and P4/mbm-Ge3P2 are 1.05 x 10(5) cm(2) V-1 s(-1) and 6.29 x 10(4) cm(2) V-1 s(-1), respectively, which are comparable to the mobility of graphene. These desirable properties of Cmmm-Ge3P2 and P4/mbm-Ge3P2 provide promising opportunities for diverse applications in electronic and optoelectronic nanodevices.