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991.
Structural design of carbon/epoxy bio‐inspired wind turbine blade using fluid/structure simulation
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Mariana Correa‐Álvarez Valentina Villada‐Quiceno Julián Sierra‐Pérez Juan Guillermo García‐Navarro César Nieto‐Londoño 《国际能源研究杂志》2016,40(13):1832-1845
The purpose of this paper is to present the structural design procedure of a low‐speed, horizontal axis, bio‐inspired wind turbine blade made of carbon/epoxy. The methodology initiates with the mechanical characterization of the carbon fiber composite material. An aerodynamic simulation using Computational Fluid Dynamics (CFD) method is performed in order to obtain the pressure distribution profile of the blade. This result is coupled with a Finite Element Analysis (FEA) to carry out an iterative design process through a Fluid‐Structure Interaction (FSI) simulation. Different stacking sequences of laminates are evaluated to find a configuration which allows balance between aerodynamic and dynamic inertial loads, ensuring an almost undeformed geometry during wind turbine's operation. The final structural design of the blade consists in six regions with different laminates. These are balanced and symmetric with distinct thickness characteristics and stacking sequences, which vary in three different orientations: 0°, ± 45° and 90°, achieving a minimum deflection at the tip close to 3.11 cm, and a total weight of 3.6 kg of a 1.8 m radius blade, even with the restrictions imposed by the non‐conventional geometry. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
992.
993.
Given that banner ad investment is huge and keeps increasing, the effectiveness of banners is important for advertising practitioners and is worth attention from academics. Banner properties (e.g. format and animation) may influence the overall effectiveness of banners. However, research on how banner formats (e.g. location and orientation) affect banner effectiveness is still in its early stage and studies on how animation influences banner effectiveness have also found controversial results. By conducting an experiment using eye-tracking technology, this study investigated the impacts of banner properties, especially animation speed and format, on users' attention, recall, and attitudes towards banners. In terms of attention, both the main effects and the interaction effect were significant and the patterns varied across time. However, no significant effects were found on recall and attitudes. 相似文献
994.
Energy‐Efficient Train Speed Profile Generator Combining Partial Energy‐Oriented Driving Approaches
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One way of reducing the energy consumption of trains is to drive them in an energy‐efficient manner. There can be various driving patterns between two adjacent stops, or various speed profiles, because there is a gap called the running time supplement between the planned running time set in a timetable and the shortest possible running time of the train. Previous studies have proposed using up the supplement by changing the driving operation from powering to coasting at optimal points in terms of energy consumption. Others have shown that full use of regenerative braking helps save energy. In this study, we developed an energy‐efficient speed profile generator by combining these partial energy‐oriented driving approaches when the planned running time is given. We added this generator to existing shortest running time calculation software, so that it works for various vehicle and train route data. Numerical experiments showed that our profile provided superior performance compared to manually created ones for artificial and real data. 相似文献
995.
通过风洞试验来研究正菱形双塔楼建筑的风荷载。根据设计软件特点,为将实验结果直接被设计软件所使用,将风压沿截面进行积分求出沿轴线和沿顺风向、横风向的合力,获得轴线整体体型系数,顺风向整体体型系数。同时将整体体型系数与单幢塔楼体型系数进行比较。 相似文献
996.
结合莱钢焦化厂4#干熄焦的现场实际,介绍了4#干熄焦提升机控制系统的构成、主要功能、提升和走行速度曲线,重点对提升机控制系统的PLC构成和控制做了介绍,整套系统自动化程度高,控制稳定、可靠。从目前的生产情况看,4#干熄焦提升机控制系统的设计完全满足干熄焦系统工艺安全、自动、高效的设计要求。 相似文献
997.
A new wind turbine emulator (WTE) is presented, which is able to simulate the turbine power curves without using a closed loop control system. The state of the art emulators use DC or AC motors, closed loop controlled by processors with the turbine power curves recorded. The presented emulator has a DC voltage source, a power resistor and a DC motor with independent excitation. The motor power curve has a shape similar to a wind turbine power curve for a given wind speed; the wind speed variations can be emulated by the variations of the DC voltage source. The open loop emulator is completely different and new, because it works in open loop and does not require the presence of a processor.The following elements are included: the theoretical foundations of the emulator, the emulator power curves adjustment procedure to simulate a commercial wind turbine and the experimental tests. 相似文献
998.
This paper investigates the current control for a grid-connected direct-drive wind energy conversion system (DDWECS) with a permanent magnet synchronous generator (PMSG), which utilizes a back-to-back pulse width modulation (PWM) converter. For the machine-side, the controller adopts a current vector control method based on the rotating reference frame (RRF) and the maximum power extraction (MPE) is realised through the tip speed ratio (TSR) method. For the grid-side, a novel controller is proposed for the first time to be successfully used for the DDWECS, which combining a proportional complex integral (PCI) current inner loop based on stationary reference frame (SRF) for regulating the grid-side current with a dc voltage outer loop for stabilizing the dc bus voltage and compare with the proportional resonant (PR) controller. A system simulation model is established by using the Matlab/Simulink to simulate the performance of the DDWECS and a prototype system has been build and tested to verify the validity of the developed control methods for both machine-side and grid-side and the excellent performance of the DDWECS. 相似文献
999.
以混凝土结构和钢结构两种不同结构形式,利用有限元分析软件ANSYS分析了该两种结构在六种不同风荷载下的最大层位移、层间位移及层间位移角的变化情况,最后通过分析,验证了两种不同结构形式的各自可行性。 相似文献
1000.
本文对高转速水轮发电机组的动平衡试验进行了研究,提出了一种比较实用的动平衡试验方法,这种方法具有仪器设备简便,启动机组次数少,平衡精度高等优点。 相似文献