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Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to explore the wake interference effect of the wind farm and quantitatively predict the overall output efficiency under different wind farm layouts, the mathematical model and prediction program of the wake interference effect was constructed. The newly established model originates from the Jensen model, which was the most commonly used to predict the wake effect of a single wind turbine, and was based on the shadowing effect and shadowing mode of the upstream wind turbine on the downstream one in the wind farm layout. The variation of wind farm overall output efficiency with wind farm scale, row/ column spacing and wind direction angle in homogeneous arrangement mode, and with dislocation spacing and wind direction angle in staggered arrangement mode were studied. The results show that the overall output efficiency increases with the increase of row/ column spacing under different wind farm scales, and decreases with the increase of wind farm scales under different row/ column spacing. There are obvious differences in the overall output efficiency of the wind farm under different dislocation spacing and wind direction angle. It is necessary to reasonably arrange the row/ column spacing of wind turbines according to the wind direction where the wind farm is located, to maximize the overall output efficiency. Research can provide guidance for the prediction of wake interference effect under any wind farm layout and rational design of wind farm layout. [ABSTRACT FROM AUTHOR]

The wake flow field around the parallel twin cylinders is complex, and a variety of complex wake patterns appear at different spacings. In this paper, based on the finite volume method, a numerical simulation of the flow around two-dimensional parallel cylinders with different spacings at low Reynolds number Re=200 was carried out. The flow field was ana-lyzed by modal comparison. The analysis results show that the proper orthogonal decomposition(POD) method can obtain the main characteristics of the dynamic system in space, and fewer modes contain most of the energy of the flow field. When the distance g=1.5 m, the interference between the upper and lower cylinders is weak, and the wake presents a periodic synchronous and co-directional pattern. When the distance g=0.35 m, the interference between the upper and lower cylinders is strong, and the flow phenomenon is more complicated. The wake presents an alternate flip pattern, and the flow field no longer has obvious periodic regularity. At the same time, the POD method can obtain the main spatial distribution chara-cteristics of the wake flow, with fewer modes containing most of the energy of the flow field, and the wake modal structure with a spacing of g=1.5 m is more compact and orderly than the modal structure with a spacing of g=0.35 m, which is closely related to the wake flow patterns under different spacing g.

It is very likely to bring safety hazards to the aircraft in the takeoff and climb or approach and landing phase for low-level wind shear in aviation flight. In severe cases, it can lead to aircraft stall or even crash. Low-altitude wind shear often also has a short duration, small scale, sudden and strong characteristics. Therefore, it is of great significance and practical value to strengthen the numerical simulation and research on aircraft encountering low-altitude wind shear in the context of the rapid development of China's civil aviation and general aviation industry. The SST model and FLUENT were used to calculate the wake vortex evolution. ANSYS FLUENT user defined function(UDF) was applied to compile seven cases with different environmental side winds for numerical simulation of the wake vortex dissipation mechanism by constructing a two-dimensional model of H-B wake vortex dissipation. It is found that the superposition of side wind and vortex-induced velocity under the influence of nonlinear vertical shear will lead to asymmetric pressure distribution around the vortex, causing the vortex pair to tilt by comparing the vortex detected in the field at Chengdu Shuangliu Airport. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)