scholarly journals Steady Wind Load on External Surface and Its Effect on Wind-Induced Response for a 200 m High Natural-Draught Cooling Tower

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Yunfeng Zou ◽  
Fanrong Xue ◽  
Xuhui He ◽  
Chenzhi Cai ◽  
Shouke Li

Wind tunnel tests were carried out to measure the wind pressure of a 200 m high natural-draught cooling tower. An analysis of the distribution characteristics of external pressure was then conducted to determine the pressure coefficients Cp(θ, z) in a given wind profile. Finally, the effect on the response of the shell and the buckling safety of the shell, applying the simplified height-constant pressure coefficient Cp(θ) and the realistic pressure Cp(θ, z), was determined. Taking the wind load specified in the code as an example, the influence of the distribution of external pressure on the wind-induced response was further analyzed. The results indicate that the pressure distribution varies with not only the height z but also the circumferential angle θ, and the wind load of both ends of the tower is significantly greater than that of its middle. Moreover, the wind-induced static responses of the tower under the action of the realistic pressure distribution Cp(θ, z) and the simplified approach Cp(θ) are basically consistent, because the wind load distribution is more important than its magnitude for the wind-induced response of cooling tower, and the wind-induced response of the cooling tower is dominated by the local shell deformation.


2012 ◽  
Vol 256-259 ◽  
pp. 788-791
Author(s):  
Zhi Xiang Yin ◽  
Yu Zhang

Open ended cantilevered roof is different from enclosed roof, because its change of wind pressure distribution is complex, and the wind directions have great influence on it. Up to now, for the characteristics of the structure are very complicated, there is no appropriate wind load model can be used in design, especially under typhoon, a specific wind field. So it is necessary to study the characteristics of wind load on open ended cantilevered roofs of typhoon. Using FLUENT and Computational Fluid Dynamics technology, based on the conventional, Tianpu’s and Shiyuan’s turbulence intensity of the typhoon scenario, a numerical simulation of wind flow around a large-span cantilevered roof was carried out. Analyzed different wind angles of the wind pressure distribution regularities on large-span cantilevered roof. The paper determined the distribution of the surface wind pressure coefficient for the cantilevered roofs, as well as the wind-sensitive parts of structures.



2008 ◽  
Vol 400-402 ◽  
pp. 935-940 ◽  
Author(s):  
Ying Ge Wang ◽  
Zheng Nong Li ◽  
Bo Gong ◽  
Qiu Sheng Li

Heliostat is the key part of Solar Tower power station, which requires extremely high accuracy in use. But it’s sensitive to gust because of its light structure, so effect of wind load should be taken into account in design. Since structure of heliostat is unusual and different from common ones, experimental investigation on rigid heliostat model using technology of surface pressure mensuration to test 3-dimensional wind loads in wind tunnel was conducted. The paper illustrates distribution and characteristics of reflector’s mean and fluctuating wind pressure while wind direction angle varied from 0° to 180° and vertical angle varied from 0° to 90°. Moreover, a finite element model was constructed to perform calculation on wind-induced dynamic response. The results show that the wind load power spectral change rulers are influenced by longitudinal wind turbulence and vortex and are related with Strouhal number; the fluctuating wind pressures between face and back mainly appear positive correlation, and the correlation coefficients at longitudinal wind direction are smaller than those at lateral direction; the fluctuating wind pressures preferably agree with Gaussian distribution at smaller vertical angle and wind direction angle. The wind-induced response and its spectrums reveal that: when vertical angle is small, the background responsive values of reflector’s different parts are approximately similar; in addition, multi-phased resonant response occurring at the bottom. With the increase of , airflow separates at the near side and reunites at the other, as produces vortex which enhances dynamic response at the upper part.





2013 ◽  
Vol 16 (6) ◽  
pp. 579-601 ◽  
Author(s):  
Jun-Feng Zhang ◽  
Yao-Jun Ge ◽  
Lin Zhao


2014 ◽  
Vol 578-579 ◽  
pp. 177-179
Author(s):  
Zi Hou Yuan ◽  
Yi Chen Yuan ◽  
Wei Sun

This paper is to study the wind load of rotary reticulated shell by experimental methods. The article conduct rigid model experiments to reticulated shell, measure wind pressure distribution on shell’top. Similar conditions is to meet production model:geometric similarity,flow similarity , Reynolds number equal. These results can be used as a reference for the new version of the wind load criteria.



2018 ◽  
Vol 18 (12) ◽  
pp. 1850156
Author(s):  
Yi Zhou ◽  
Yuanqi Li ◽  
Akihito Yoshida

Flexible roof structures, such as membranes, are sensitive to wind action due to their flexibility and light weight. Previously, the effect of added mass on the vibration frequency of membrane structures has been experimentally tested. However, the effect of added mass on wind-induced vibration remains unclear. The purpose of this paper is to investigate the effect of added mass on the wind-induced vibration of a circular flat membrane based on wind tunnel tests. First, wind tunnel tests were conducted to obtain wind pressure distribution from the rigid model and wind-induced vibration from the aeroelastic model of a circular flat membrane. Secondly, a dynamic finite element analysis for the proposed added mass model was conducted to obtain the wind-induced vibration of the membrane structure. Then, with the wind pressure distribution obtained from the rigid model tests, dynamic analysis was conducted either with or without consideration of the effect of added mass. According to the dynamic analysis results and the wind tunnel test results, it is clear that considering the effect of added mass in dynamic analysis can significantly improve the accuracy of a wind-induced response. Such an effect is more significant at the windward than the central zone. The inclusion of added mass can result in a larger displacement response as wind velocity increases but a smaller response as the prestress level increases.



2018 ◽  
Vol 2018 ◽  
pp. 1-22 ◽  
Author(s):  
Shitang Ke ◽  
Wenlin Yu ◽  
Yaojun Ge

By focusing on wind-rain two-way coupling algorithm, simulation iterations of wind field and raindrops in the world highest cooling tower (210m) in northwest China were carried out using continuous phase and discrete phase models based on CFD numerical simulation. Firstly, influence laws of 9 wind velocity-rainfall intensity combinations on wind-induced rainfall, raindrop additional force, and equivalent pressure coefficient on internal and external surface of the tower body were discussed. On this basis, speed flow line, turbulence energy strength, raindrop running speed, and track on the tower body in the wind-rain coupling field were disclosed. Finally, qualitative and quantitative contrastive analyses on wind pressure, rain pressure, and equivalent pressure coefficient on internal and external surfaces of the tower body were conducted under different working conditions. Thus, the most unfavorable wind-rain combination was identified. Calculation formulas of equivalent internal and external pressure coefficients of super-large cooling towers were fitted from nonlinear least square method. Research results demonstrate that the 3D effect of equivalent internal and external pressure coefficients with considerations to wind-rain two-way coupling is more prominent. Particularly, there is strong transition on the windward region of the external surface and leeside region at bottom of internal surface. The quantity of caught raindrops on the structural surface is negatively related to wind velocity but is positively related to rainfall intensity. Rain load and rainfall coefficients on the external surface are significantly higher than those on the internal surface. Equivalent internal pressure coefficient has a sharp reduction on the leeside region under different working conditions. Besides, equivalent internal pressure coefficient of different meridians decreases with the increase of height. The maximum and minimum are -0.574 and -0.282, respectively. The proposed equivalent internal and external pressure coefficients of super-large cooling tower can predict wind load under extreme climate conditions accurately.



2013 ◽  
Vol 405-408 ◽  
pp. 710-712
Author(s):  
Zi Hou Yuan ◽  
Yi Chen Yuan ◽  
Wei Sun

In order to investigate the pressure distribution around the reticulated shell structure with large span, a commercial Computational Fluid Dynamic software Fluent is employed to obtain the wind load and the coefficients of the time averaged pressure distribution around the reticulated shell structure in this paper. The numerical simulations of surface pressure are consistent with the experimental results. The characteristics of the wind pressure distribution are described through the flow analysis around the reticulated shell structure. All these discoveries can be used as a reference for the new version of the wind load criteria.



2010 ◽  
Vol 163-167 ◽  
pp. 4280-4285
Author(s):  
Di Wu ◽  
Ying Sun ◽  
Yue Wu

Taking Harbin west railway station as the researching object, the wind load distribution as well as its effects, which are widely used in practice, is investigated. First, wind pressure distribution on a rigid model is measured simultaneously in a wind tunnel. Some special characteristics of the measured wind pressure, especially its fluctuating component, are discussed. Then the fluctuating wind pressure field is reconstructed based on the synchronous multi-pressure scanning technique of wind tunnel tests and the proper orthogonal decomposition (POD) technique. The influence of lower RC structure on wind-induced vibration is investigated using non-linear time-history analysis. At last, a new method is introduced to obtain equivalent static wind load (ESWL) that reproduce all largest load effects at the same time. With the synthetic application of above methods, the problems such as: complex time and spatial distribution of fluctuating wind; multi-mode vibration of wind-induced response; multiple equivalent objectives for ESWL, can be solved efficiently.



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