The Influence of the Wind Flow Around the Free Ends of High-Rise Building on the Values of External Wind Pressure Coefficients

2016 ◽  
Vol 837 ◽  
pp. 203-208 ◽  
Author(s):  
Olga Hubova ◽  
Lenka Konecna

The external wind pressure coefficients are based on the measurements on the structures without free-end flow near the top of vertical structures. The end-effect factor takes into account reduction of the pressures due to specific flow around the top of atypical building. The article is based on the experimental measurements in BLWT tunnel in Bratislava on the model of building with cross section of the quarter circle. The model was tested in two spaces - in steady and turbulent wind flow, by changing of wind direction and wind velocity. The end-effect factor depending on the wind direction is shown in the graphs.

2017 ◽  
Vol 13 (2) ◽  
pp. 149-155
Author(s):  
Soňa Medvecká ◽  
Oľga Ivánková ◽  
Marek Macák

Abstract Analysis of wind flow acting upon high-rise buildings is a very common topic. This paper deals with experiment in the Boundary Layer Wind Tunnel (BWLT) in Bratislava and comparison with the computational fluid dynamics (CFD) simulation and values given in the Eurocode. The analyzed object was the model of building with circular cross section (cylinder). External wind pressure coefficients were compared in three height levels of model.


2020 ◽  
Vol 313 ◽  
pp. 00047
Author(s):  
Michal Franek ◽  
Marek Macák ◽  
Oľga Hubová

The wind flow around the elliptical object was investigated experimentally in the BLWT wind tunnel in Bratislava and subsequently solved by computer wind flow simulation. On a high-rise building model, the external wind pressure coefficients were evaluated for different wind directions and then compared with the numerical CFD simulation in ANSYS, where different models of turbulence and mesh types were used. The aim of the article was to evaluate and compare the obtained values and after analysing the results to choose the most suitable model of turbulence and mesh types, which showed the smallest deviations from the experimental values.


2021 ◽  
Vol 11 (15) ◽  
pp. 7121
Author(s):  
Shouke Li ◽  
Feipeng Xiao ◽  
Yunfeng Zou ◽  
Shouying Li ◽  
Shucheng Yang ◽  
...  

Wind tunnel tests are carried out for the Commonwealth Advisory Aeronautical Research Council (CAARC) high-rise building with a scale of 1:400 in exposure categories D. The distribution law of extreme pressure coefficients under different conditions is studied. Probability distribution fitting is performed on the measured area-averaged extreme pressure coefficients. The general extreme value (GEV) distribution is preferred for probability distribution fitting of extreme pressure coefficients. From the comparison between the area-averaged coefficients and the value from GB50009-2012, it is indicated that the wind load coefficients from GB50009-2012 may be non-conservative for the CAARC building. The area reduction effect on the extreme wind pressure is smaller than that on the mean wind pressure from the code. The recommended formula of the area reduction factor for the extreme pressure coefficient is proposed in this study. It is found that the mean and the coefficient of variation (COV) for the directionality factors are 0.85 and 0.04, respectively, when the orientation of the building is given. If the uniform distribution is given for the building’s orientation, the mean value of the directionality factors is 0.88, which is close to the directionality factor of 0.90 given in the Chinese specifications.


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.


2020 ◽  
Vol 313 ◽  
pp. 00048
Author(s):  
Ivana Veghova ◽  
Olga Hubova

This article deals with experimental investigation of a wind pressure distribution on multispan roofs of halls. The wind pressure distribution on the structures is an important parameter in terms of wind load calculation. For multispan roofs it is possible to find these values in Eurocode 1991-1-4, but without an influence of surrounding structures. The series of parametric wind tunnel studies was carried out in BLWT to investigate the effects of in-line standing cylinders near the hall. Measurements were made in turbulent wind flow for two reference wind speeds and varying wind directions. The experimentally obtained cpe values were compared with the conservative values in EN 1991-1-4 for multispan roofs.


2020 ◽  
Vol 310 ◽  
pp. 00013 ◽  
Author(s):  
Ivana Veghova ◽  
Olga Hubova

This article deals with experimental investigation of air flow around in – line standing circular cylinders and influence of nearby standing hall on external wind pressure distribution. The wind pressure distribution on the structures is an important parameter in terms of wind load calculation. For vertical circular cylinders in a row arrangement only wind force coefficient is possible find in Eurocode. 1991-1-4. External wind pressure coefficient depends on wind direction and the ratio of distance and diameter b. Influence of nearby standing structure is not possible find in Eurocode. The series of parametric wind tunnel studies was carried out in Boundary Layer Wind Tunnel (BLWT) STU to investigate the external wind pressure coefficient in turbulent wind flow. Experimental measurements were performed in BLWT for 2 reference wind speeds, which fulfilled flow similarity of prototype and model. We have compared the results of free in - line standing 3 circular cylinder and influence of hall on distribution of wind pressure at 3 height levels in turbulent wind flow and these results were compared with values in EN 1991-1-4.


Fluids ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 81
Author(s):  
Norbert Jendzelovsky ◽  
Roland Antal

There is a lack of detailed information about wind flow and distribution of wind pressure around atypically shaped high-rise buildings. The national standard EN 1991-1-4 Eurocode 1 used to determine the effects of wind on the territory of Slovakia (and indeed other countries of the European Union) does not have a procedure for determining the effects of wind on objects of triangular shape. This presents a problem for designers and engineers, as there exist no generally binding/valid rules to follow when performing the wind effect analysis. This paper shows the procedure of identification and results of the external wind pressure coefficient for the triangularly shaped high-rise building. Two methods of calculation have been chosen for this purpose. First, experimental measurements were performed on a scaled model of the building cross-section in the wind tunnel. Subsequently, software simulations were performed on the same scaled model in the CFD (computational fluid dynamics) program ANSYS CFX. Results of wind pressure were obtained for two directions of wind flow measured in 16 sampling points distributed irregularly around the circumference of the model. Results were mutually compared and verified. At the end, the wind flow effects on a real-size triangular high-rise building in the built-up area performed by software simulation are shown.


2013 ◽  
Vol 12 (2) ◽  
pp. 111-118
Author(s):  
Paulina Jamińska

In the present study an attempt to evaluate the effect of wind action on the building - scaffolding system was made. Analysis was based on the CFD simulations using ANSYS FLUENT and RNG k-ε turbulence model. Calculations were performed for 2D case of building of rectangular cross-section. Turbulent wind flow was modelled around the building and the building with a scaffolding set along longer wall. Four different angles of wind attack: 0 °, 45 °, 90 ° and 135 ° were taken into account. The results are shown in the form of pressure distribution on the walls of model and the velocity distribution in the computational domain, and later compared to the standard recommendations for scaffoldings. The analysis indicated that the actual flow around a building with scaffolding is much more complicated than the flow shown in standards. It can even lead to scaffold collapse due to the wind induced torque forces.


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