Wind Tunnel Tests and Numerical Simulations of Wind-Induced Snow Drift in an Open Stadium and Gymnasium

A long-span sports centre generally comprises multiple stadiums and gymnasiums, for which mutual interference effects of wind-induced snow motion are not explicitly included in the specifications of various countries. This problem is addressed herein by performing wind tunnel tests and numerical simulations to investigate the snow distribution and mutual interference effect on the roofs of long-span stadiums and gymnasiums. The wind tunnel tests were used to analyse the influences of the opening direction (0°, 90°, 180°, and 270°) and spacing (0.3 L, 0.5 L, 1 L, 1.5 L, 2 L, and 2.5 L, where L is the gymnasium span) of the stadium and gymnasium. The wind tunnel tests and numerical simulations were used to analyse the influence of the wind direction angle (from 0° to 315°, there are a total of eight groups in 45° intervals). The following results were obtained. The stadium opening had a significant effect on the snow distribution on the surface of the two structures. An even snow distribution was obtained when the stadium opened directly facing the gymnasium, which corresponded to the safest condition for the structures’ surfaces. As the spacing between the buildings increased, the interference effect between the two structures was reduced. The interference was negligible for a spacing of 2 L. The stadium had the most significant amplification interference effect on the gymnasium for a wind direction angle of 45°, which was extremely unfavourable to the safety of the structure. The most favourable wind direction angle was 270°, where there were both amplification interference and blockage interference.

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Research on Snow Load Characteristics on a Complex Long-Span Roof Based on Snow–Wind Tunnel Tests

Applied Sciences ◽

10.3390/app9204369 ◽

2019 ◽

Vol 9 (20) ◽

pp. 4369 ◽

Cited By ~ 2

Author(s):

Guolong Zhang ◽

Qingwen Zhang ◽

Feng Fan ◽

Shizhao Shen

Keyword(s):

Wind Tunnel ◽

Basic Characteristic ◽

Wind Tunnel Test ◽

Experimental System ◽

Similarity Criteria ◽

Wind Tunnel Tests ◽

Snow Load ◽

Long Span ◽

Characteristic Modes ◽

Snow Distribution

A considerable number of studies have been carried out for predicting snowdrifts on roofs over the years. However, few studies have focused on snowdrifts on complex long-span roofs, as the complex shape and fine structure pose significant challenges. In this study, to simplify the calculation requirements of snow load on such roofs, work was conducted to decompose the snowdrift on a complex roof into snowdrifts on several simple roofs. First, the snow–wind tunnel test similarity criteria were investigated based on a combined air–snow–wind experimental system. Thereafter, with reference to the validated experimental similarity criteria, a series of snow–wind tunnel tests were performed for snowdrifts on a complex long-span structure under the conditions of different inflow directions. Finally, based on empirical orthogonal function (EOF) analysis, the snowdrifts on the complex roof were decomposed into basic characteristic distribution modes, including snowdrifts caused by the local and overall roof forms. The snow distribution under a specific inflow direction could be derived from the weighted combination of the basic characteristic modes, based on the wind direction coefficients. Therefore, it is possible for the snow load on a complex roof to be estimated preliminarily based on the snow distributions on several simple roofs.

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Wind-Induced Phenomena in Long-Span Cable-Supported Bridges: A Comparative Review of Wind Tunnel Tests and Computational Fluid Dynamics Modelling

Applied Sciences ◽

10.3390/app11041642 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1642

Author(s):

Yuxiang Zhang ◽

Philip Cardiff ◽

Jennifer Keenahan

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Wind Tunnel ◽

Careful Analysis ◽

Wind Effects ◽

Wind Tunnel Tests ◽

Long Span Bridges ◽

Long Span ◽

Comparative Review ◽

Dynamics Modelling

Engineers, architects, planners and designers must carefully consider the effects of wind in their work. Due to their slender and flexible nature, long-span bridges can often experience vibrations due to the wind, and so the careful analysis of wind effects is paramount. Traditionally, wind tunnel tests have been the preferred method of conducting bridge wind analysis. In recent times, owing to improved computational power, computational fluid dynamics simulations are coming to the fore as viable means of analysing wind effects on bridges. The focus of this paper is on long-span cable-supported bridges. Wind issues in long-span cable-supported bridges can include flutter, vortex-induced vibrations and rain–wind-induced vibrations. This paper presents a state-of-the-art review of research on the use of wind tunnel tests and computational fluid dynamics modelling of these wind issues on long-span bridges.

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Flutter mitigation of a superlong-span suspension bridge with a double-deck truss girder through wind tunnel tests

Journal of Vibration and Control ◽

10.1177/1077546320946150 ◽

2020 ◽

pp. 107754632094615

Author(s):

Yanguo Sun ◽

Yongfu Lei ◽

Ming Li ◽

Haili Liao ◽

Mingshui Li

Keyword(s):

Wind Tunnel ◽

Damping Ratio ◽

Suspension Bridge ◽

Wind Tunnel Tests ◽

Long Span Bridges ◽

Long Span ◽

Upper Deck ◽

Torsional Damping ◽

And Control ◽

Wind Induced Vibration

As flutter is a very dangerous wind-induced vibration phenomenon, the mitigation and control of flutter are crucial for the design of long-span bridges. In the present study, via a large number of section model wind tunnel tests, the flutter performance of a superlong-span suspension bridge with a double-deck truss girder was studied, and a series of aerodynamic and structural measures were used to mitigate and control its flutter instability. The results show that soft flutter characterized by a lack of an evident divergent point occurred for the double-deck truss girder. Upper central stabilizers on the upper deck, lower stabilizers below the lower deck, and horizontal flaps installed beside the bottoms of the sidewalks are all effective in suppressing flutter for this kind of truss girder. By combining the structural design with aerodynamic optimizations, a redesigned truss girder with widened upper carriers and sidewalks, and double lower stabilizers combined with the inspection vehicle rails is identified as the optimal flutter mitigation scheme. It was also found that the critical flutter wind speed increases with the torsional damping ratio, indicating that the dampers may be efficient in controlling soft flutter characterized by single-degree-of-freedom torsional vibration. This study aims to provide a useful reference and guidance for the flutter design optimization of long-span bridges with double-deck truss girders.

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An investigation of snow drifting on flat roofs: Wind tunnel tests and numerical simulations

Cold Regions Science and Technology ◽

10.1016/j.coldregions.2019.03.016 ◽

2019 ◽

Vol 162 ◽

pp. 74-87 ◽

Cited By ~ 6

Author(s):

Zhixiang Liu ◽

Zhixiang Yu ◽

Fu Zhu ◽

XiaoXiao Chen ◽

Yi Zhou

Keyword(s):

Wind Tunnel ◽

Numerical Simulations ◽

Wind Tunnel Tests ◽

Snow Drifting ◽

Flat Roofs

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Wind Tunnel Tests of Wind-Induced Snow Distribution for Cubes with Holes

Advances in Civil Engineering ◽

10.1155/2019/4153481 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Xintong Jiang ◽

Zhixiang Yin ◽

Hanbo Cui

Keyword(s):

Wind Tunnel ◽

Snow Depth ◽

Structural Safety ◽

Windward Side ◽

Leeward Side ◽

Wind Tunnel Tests ◽

Maximum Snow Depth ◽

Adjacent Structures ◽

Significant Difference ◽

Snow Distribution

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.

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