scholarly journals Study of Wind Force Coefficient on Four-flue Chimney Supported by Hexagon Shaped Steel Tower

2018 ◽  
Vol 43 (1) ◽  
pp. 14-25
Author(s):  
Hidekazu ISHII ◽  
Sadato SUGIYAMA
Keyword(s):  
1978 ◽  
Vol 100 (3) ◽  
pp. 340-342 ◽  
Author(s):  
R. E. Wilson

A two-dimensional analysis of the performance and flowfield of the Giromill is presented. The Giromill is a vertical-axis wind turbine with straight blades that are articulated to produce maximum energy extraction from the wind. It is found that the power coefficient and windwise force coefficient for the Giromill have the same limit as obtained for the horizontal-axis wind turbine. A cross-wind force is also obtained with this type of wind turbine. The cross-wind force is of second order and decreases with tip speed. Streamlines and velocity profiles are illustrated for several loading conditions.


Author(s):  
Hiroki Takahashi ◽  
Katsutoshi Ohdo ◽  
Seiji Takanashi

The Japanese Industrial Safety and Health Law was revised in March 2009 to introduce new measures concerning accidental falls in the construction industry. This revision mandates the use of guard rails, handrails, and other scaffold components. The wind load criteria and structural specifications of scaffolds are regulated by current design codes. Nevertheless, these provisions do not necessarily comply with the newly incorporated legal requirements because they apply to old-style scaffolds. This study examined the wind force on scaffolds by wind tunnel test, with baseboard height used as a parameter. The wind force coefficient of one story of scaffolds was calculated. Wind force coefficient increased as baseboard height increased. The wind force on the scaffolds equipped with baseboards is 9.2 times that on the scaffolds without baseboards. The baseboard must be greater than or equal to 15 cm to satisfy regulation requirements. The wind force coefficient of scaffolds with a 15 cm baseboard is 1.5 times that of the scaffolds without a baseboard. In scaffold design, baseboard height should be considered to guarantee a suitable wind force coefficient.


Author(s):  
Yasushi Uematsu ◽  
Jumpei Yasunaga ◽  
Choongmo Koo

Wind force coefficients for designing open-topped oil-storage tanks in various arrangements have been investigated under experiments involving a wind tunnel and a buckling analysis of the tanks. In the wind tunnel experiment, the wind pressures were measured simultaneously at many points both on the external and internal surfaces of a rigid model for various arrangements of two to four tanks. The effects of arrangement and gap spacing of tanks on the pressure distribution are investigated. The buckling of tanks under static wind loading is analyzed by using a non-linear finite element method. A discussion of the effect of wind force distribution on the buckling behavior follows. The authors provided a model of circumferential distribution of wind force coefficient on isolated open-topped tanks in their previous paper. This paper proposes a model of wind-force coefficient for plural tanks in various configurations by modifying the model for isolated tanks.


Author(s):  
Hiroki Takahashi ◽  
Katsutoshi Ohdo ◽  
Kazuo Ohgaki

When scaffolds are installed in construction sites, their resistance against wind force needs to be calculated. Japanese design guidelines require a specific scaffold resistance against wind force, but such rules and regulations are applicable solely to old-style scaffolds. A number of risks are inherent in the existing guidelines. First, new-style scaffolds are used in construction sites without practitioners knowing whether the design guidelines are appropriate for modern building components. Second, scaffolds are set near buildings, but workers are unaware of the effect of the wind force at the building edge. Finally, conventional designs feature the use of baseboards as scaffold components. While considering the aforementioned issues, a wind tunnel test was carried out as part of this study to examine the wind force exerted on scaffolds erected near a building edge. The parameters used in the test were baseboard height and the distance from the building edge. From the results, when the distances between the building’s center and the scaffold’s center are 180 mm, the wind force is high. Additionally, when the baseboard height is 130 mm, the wind force is high. This study examined the correction number for the wind force coefficient of scaffolds with baseboards that were positioned at building edge. Whenever the scaffolds were set near the building edge, we needed to revise the wind force coefficient of the scaffolds.


2011 ◽  
Vol 36 (4) ◽  
pp. 343-361
Author(s):  
Hiroshi TERAZAKI ◽  
Akira KATSUMURA ◽  
Yasushi UEMATSU ◽  
Kazuo OHTAKE ◽  
Yasuo OKUDA ◽  
...  
Keyword(s):  

2021 ◽  
Vol 13 (7) ◽  
pp. 3944
Author(s):  
Jangyoul You ◽  
Myungkwan Lim ◽  
Kipyo You ◽  
Changhee Lee

Solar panels installed on the ground receive wind loads. A wind experiment was conducted to evaluate the wind force coefficient acting on a single solar panel and solar panels arranged in an array. The surface roughness did not have a significant effect on the change in vertical force, which is the wind force coefficient acting on the vertical surface of a single solar panel. An examination of the change in wind direction angle showed that the largest vertical force coefficient was distributed in the 0° forward wind direction on the front of the solar panel, the 345° reverse wind direction on the rear side, and the 135° and 225° diagonal directions on the rear panel. Furthermore, an examination of the change in wind force coefficient according to the change in solar panel inclination angle (β) showed that the drag coefficient was the highest at the 40° inclination angle of the panel (β), followed by the 30° and 20° inclination angles. However, the lift coefficient and vertical force coefficient were not significantly affected by the inclination angle of the panel. The wind force coefficient of the panels arranged in an array was influenced by the wind direction angle and panel position. With the exclusion of the nearest row at a wind direction angle of 0°, all the panels in the array showed lower coefficients than those in the single-panel experiment. In the case of the panels placed inside, the wind speed was decreased by the surrounding panels. As a result, the wind force coefficient was lower than that of the single-panel experiment. This outcome is attributed to the small delamination at the end of the panels by the surrounding array of panels compared with that of the single-panel experiment.


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