The Numerical Simulation of the Impact on the Hangzhou Bay Bridge Offshore Platform and the Sightseeing Tower

2012 ◽  
Vol 532-533 ◽  
pp. 352-356
Author(s):  
Hua Bai ◽  
Fang Liang Wang ◽  
Yu Li

In this paper, the distribution of surface wind pressure and wind speed of Hangzhou bay bridge, offshore platform and sightseeing tower is numerically simulated based on Fluent. Two turbulence models, standard k ε model and Realizable k ε model, are used. The influence of the wind pressure distribution of the offshore platform and sightseeing tower by Hangzhou bay bridge is also analyzed. And the detailed comparison between numerical simulation and wind tunnel test is given. Results show that the impact of Hangzhou bay bridge on platform and sightseeing tower occurs mainly with the angle of the wind less than 450. When the angle of the wind is more than 450, the impact is little. The upper of the sightseeing tower does not almost suffer the effect of other buildings. The surface pressure of the platform changes from 5% to 15% between under bridge and under non-bridge condition. The surface pressure of sightseeing tower changes from 0.05% to 3%. The influence on the platform by the bridge is significant but not significant on the sightseeing tower. The simulation results of the tower and mast structure given by both standard k ε model and Realizable k ε model find that the windward side is ideal; the crosswind side is the best; the leeward side is less than ideal. By contrast, the Realizable k ε model is a closer correlation with wind tunnel test than standard k ε model.

2012 ◽  
Vol 226-228 ◽  
pp. 1260-1264
Author(s):  
Xi Meng ◽  
Ri Gao ◽  
Hai Jun Zhang

In order to determine the distribution of wind load on the roof, wind tunnel test and numerical simulation are both carried out. Then the distribution of mean wind pressure under different wind directions is obtained and the features of mean wind pressure are also analyzed. The datas show that wind pressure distribution of the roof is predominantly negative pressure; only a small area of windward side is positive pressure distribution. The peak of negative pressure appears at the roof ridge or windward long eaves, and varies as changes of wind direction. Meanwhile, the comparison between the results of the numerical simulation and wind tunnel test shows that the distribution law of both is almost the same, but in some areas that flow separation is serious, the error is larger. Then the reasons for the error are discussed.


2013 ◽  
Vol 423-426 ◽  
pp. 2063-2067
Author(s):  
Bo Zhang ◽  
Shu Shan Wang ◽  
Meng Yu Cao ◽  
Yu Xin Xu

A wind tunnel test is designed to study aerodynamic effects of one individual rocket with deflectable nose. The test measures pressure with U-bend tube which is cost effective. Using rubber tubes in different lengths to measure pressure distributions of a flat-plate, and calculating how rubber tube affects the measurement, in order to modify the measured surface pressure of the nose. The surface pressure varies on different points while yawing angle and attack angle changes, the changing regularity could provide data for following numerical simulation and trajectory control.


2021 ◽  
Author(s):  
Shahab IbrahimPour ◽  
Alireza KhavaninZadeh ◽  
Ruhollah Taghizadeh mehrjardi ◽  
Hans De Boeck ◽  
Alvina Gul

Abstract Destructive mining operations are affecting large areas of natural ecosystems, especially in arid lands. The present study aims at investigating the impact of iron mine exploitation on vegetation and soil in Nodoushan (Yazd province, central Iran). Based on the dominant wind, topography, slope, vegetation and soil of the area, soil and vegetation parameters close to ​the mine were recorded and analyzed according to the distance from the mine. In order to obtain the vegetation cover, a transect and plot on the windward and leeward side of the mine, with 100 m intervals and three replicates at each sampling location was used, yielding 96 soil samples. The amount of dust on the vegetation, the seed weight and seed germination rate of Artemisia sp. as the dominant species within the area, and the soil microbial respiration were measured. The relationship between vegetation cover and distance from the mine was not linear, which was due to an interplay between pollution from the mine and local grazing, while other factors did increase or decrease linearly. The results showed that, as the distance from the mine increased, the weight of 1000 seeds of Artemisia sp. was significantly increased from 271 to 494 mg and seed germination rate and soil microbial respiration were significantly increased from 11.7 to 48.4 % and from 4.5 to 5.9 mg CO2 g− 1 soil day− 1 respectively, while the amount of dust significantly decreased from 43.5 to 6 mg (g plant)−1 between the distance of 100 to 600 m from the mine in the leeward direction. A similar trend was observed in the windward side, though negative effects were lower compared to the same distance along the leeward sample locations. The direct and indirect effects on plant growth and health from mining impacts generally decreased linearly with increasing distance from the mine, up to at least 600 m. Our study serves as a showcase for the potential of bio-indicators as a cost-effective method for assessing impacts of mining activities on the surrounding environment.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Xintong Jiang ◽  
Zhixiang Yin ◽  
Hanbo Cui

The nonuniform distribution of snow around structures with holes is extremely unfavorable for structural safety, and the mechanism of wind-snow interaction between adjacent structures with holes needs to be explored. Therefore, a wind tunnel simulation was performed, in which quartz particles with an average particle size of 0.14 mm as snow particles were used, and cubes with dimensions of 100 mm × 100 mm × 100 mm each containing a hole with the size of 20 mm × 20 mm were employed as structures. Firstly, the quality of a small low-speed wind tunnel flow field was tested, and then the effects of hole orientation (hole located on the windward side, leeward side, and other vertical sides) and absence of holes on the surface of a single cube were studied. Furthermore, the effects of different hole locations (respectant position, opposite position, and dislocation) and relative spacing (50 mm, 100 mm, and 150 mm) on the surfaces of two cubes and the snow distribution around them were investigated. It was concluded that the presence and location of hole had a great influence on snow distribution around cubes. Snow distribution was favorable when hole was located on the other vertical sides of the test specimen. The most unfavorable snow distribution was obtained when the holes on the two-holed sides of the cubes were respectant with a maximum snow depth coefficient of 1.4. A significant difference was observed in the snow depths of two sides of cubes when holes were dislocated. When two holes were respectant, surrounding snow depth was decreased, and the maximum snow depth on model surface area was increased with the increase of spacing. Wind tunnel tests on holed cubes provided a reference for the prediction of snow load distribution of typical structures with holes.


2020 ◽  
Vol 2020 ◽  
pp. 1-24
Author(s):  
Fu-Bin Chen ◽  
Xiao-Lu Wang ◽  
Yun Zhao ◽  
Yuan-Bo Li ◽  
Qiu-Sheng Li ◽  
...  

High-rise buildings are very sensitive to wind excitations, and wind-induced responses have always been the key factors for structural design. Facade openings have often been used as aerodynamic measures for wind-resistant design of high-rise buildings to meet the requirement of structural safety and comfort. Obvious wind speed amplifications can also be observed inside the openings. Therefore, implementing wind turbines in the openings is of great importance for the utilization of abundant wind energy resources in high-rise buildings and the development of green buildings. Based on numerical simulation and wind tunnel testing, the wind loads and wind speed amplifications on high-rise buildings with openings are investigated in detail. The three-dimensional numerical simulation for wind effects on high-rise building with openings was firstly carried out on FLUENT 15.0 platform by SST k − ε model. The mean wind pressure coefficients and the wind flow characteristics were obtained. The wind speed amplifications at the opening were analyzed, and the distribution law of wind speed in the openings is presented. Meanwhile, a series of wind tunnel tests were conducted to assess the mean and fluctuating wind pressure coefficients in high-rise building models with various opening rates. The variation of wind pressure distribution at typical measuring layers with wind direction was analyzed. Finally, the wind speed amplifications in the openings were studied and verified by the numerical simulation results.


2010 ◽  
Vol 163-167 ◽  
pp. 4389-4394
Author(s):  
Cheng Qi Wang ◽  
Zheng Liang Li ◽  
Zhi Tao Yan ◽  
Qi Ke Wei

Wind load on complex-shape building, the wind tunnel test and numerical simulation were carried out. The two technologies supplement each other and their results meet well. There are mainly positive pressures on the windward surface, negative pressures on the roof, the leeward surface and the side. Especially, negative pressure is higher in the leeward region of the building corner. Its effect induced by the shape of the complex-shape building is remarkable.


2011 ◽  
Vol 94-96 ◽  
pp. 1026-1030
Author(s):  
Yue Ming Luo ◽  
Yue Yin ◽  
Xi Liang Liu

Due to the increasing of wind disaster, structural wind engineering arouses more and more attention recently, with rapid development on spatial structure and continuous innovation of structural style. The main purpose of structural wind engineering is to calculate the wind pressure coefficients of structure. In this paper, the numerical wind tunnel method (NWTM), based on the Computational Fluid Dynamics (CFD), is applied to study wind load. The wind pressure coefficients of reticulated spherical shell with the 4.6m high wall were first determined, using the NWTM. The results are then compared with the wind tunnel test (WTT) and good agreement is found. The feasibility and reliability of NWTM were then verified. As the second example, NWTM is carried out to predict wind-induced pressure on reticulated spherical shell without wall. Further the distribution behavior of wind pressures on this kind of structures is discussed which could provide professionals the reference for the design of structure.


Author(s):  
Daniel Barcarolo ◽  
Yann Andrillon ◽  
Erwan Jacquin ◽  
Alain Ledoux

The accurate evaluation of wind loads applied on floating offshore structures is extremely important as they are in specific conditions one of the dimensioning criteria for the mooring design. Nowadays these loads are mainly assessed through wind tunnel tests performed at model scale. Estimating realistic wind loads however, remains a big challenge. The complexity and associated simplification level of FPSO topside structures, the scale effects and the establishment of the atmospheric boundary layer imply that many simplifications are to be made. Typically, the FPSO topside is greatly simplified and equivalent blocs of wired frame are used. Today with the evolution of CFD software, and the increase of the meshing capacity, new scopes open to CFD. Aerodynamic simulations on complex FPSO structures are therefore now possible, but need specific developments and validations that are presented in this paper. The main objective of the work presented is to investigate the ability of CFD to evaluate wind loads on complex FPSOs topsides and to provide information on the impact of model simplifications made in wind tunnels. In a first stage, the numerical model was intensively validated by comparing its results to a wind tunnel test case. The numerical model was developed in order to ensure the quality of the results and enable a relevant comparison that was obtained with grids density up to 30 million cells. For this purpose, the geometric model used corresponds to the one used in wind tunnel. The same Atmospheric Boundary Layer was simulated and a thorough effort was performed to ensure the mesh convergence. In a second stage, more physical aspects of the wind tunnel methodology were investigated. Typically the accuracy of the blockage effect correction was evaluated by performing computations with and without blockage, and results were compared with classical corrections applied in wind tunnel. The impacts of the Atmospheric Boundary Layer on wind loads have also been investigated. Finally, the wind load contribution of each component of the FPSO was evaluated.


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