Research on the Aerodynamic Measures Impact on Flutter Stability of Steel Truss Suspension Bridge

2013 ◽  
Vol 791-793 ◽  
pp. 378-381
Author(s):  
Hua Bai ◽  
Sen Hua Huang
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Suspension Bridge ◽  
Wind Tunnel Experiment ◽  
Attack Angle ◽  
Torsional Stiffness ◽  
Critical Wind Speed ◽  
Guide Plate ◽  
Steel Truss ◽  
Better Than

The flutter stability of the steel truss suspension bridge is hard to reach the requirement of the wind resisting stability when lacks the torsional stiffness. This paper discusses the influence of aerodynamic measure combination, such as central stabilizer, air director enclosed anti-collision bar and so on, towards the flutter stability of steel truss through the wind tunnel experiment of the bridge of Liu Jia gorge. The result shows: the effect of using both the upper and lower stabilized plate is better than separated used it. when sectionalized dispose upper stabilized plate, the flutter critical wind speed of attack angle will decrease rapidly. Outlaying the horizontal guide plate is better than internally installed; The flutter stability of different attack angle tend to be balanced by widening the horizontal guide plate. The anti-collision bar can be functionalized as the central stabilizer by heightening and enclosing, and effectively increase the critical wind speed of different attack angles of the high truss suspension bridge.

scholarly journals Effects of central stabilizing barriers on flutter performances of a suspension bridge with a truss-stiffened deck under skew winds

2018 ◽  
Vol 22 (1) ◽  
pp. 17-29 ◽  
Author(s):  
Ledong Zhu ◽  
Xiao Tan ◽  
Zhenshan Guo ◽  
Quanshun Ding
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Inclination Angle ◽  
Suspension Bridge ◽  
Control Measures ◽  
Wind Effect ◽  
Wind Condition ◽  
Wind Tunnel Tests ◽  
Critical Wind Speed ◽  
Bridge Span

To improve the flutter performance of a suspension bridge with a 1088-m-span truss-stiffened deck, the aerodynamic measures of upper and lower central stabilizing barriers were investigated at first via wind tunnel tests of sectional model under the normal wind condition. The yaw wind effect on the flutter performance of the bridge with the above aerodynamic measures was then examined via a series of wind tunnel tests of oblique sectional models. The test results show that the effect of the lower central stabilizing barrier on the flutter critical wind speed is remarkably different from that of the upper central stabilizing barrier for both the normal and skew wind cases. The inclination angle +3° is the most unfavorable inclination angle to the flutter performance of the truss-stiffened suspension bridge no matter whether the aerodynamic control measures are adopted or not. Furthermore, for most cases, the lowest flutter critical wind speed occurs when the incident wind deviates from the normal direction of the bridge span by a small yaw angle between 5° and 10°.

Wind Tunnel Studyon Vortex-Induced Vibration Characteristics of Long-Span Suspension Bridges with Single Cable Plane

2014 ◽  
Vol 633-634 ◽  
pp. 1263-1266
Author(s):  
Huang Yu
Keyword(s):  
Wind Tunnel ◽  
Suspension Bridge ◽  
Wind Tunnel Experiment ◽  
Vibration Characteristics ◽  
Torsional Stiffness ◽  
Suspension Bridges ◽  
Vortex Induced Vibration ◽  
Long Span Bridges ◽  
Wind Speeds ◽  
Long Span

For modern long-span bridges, both the optimization of aerodynamic shape and the increase of torsional stiffness according to the result of the wind tunnel experiment could avoid the flutter instability.Vortex-inducedvibration with relatively large amplitude happens easily at low wind speeds. In this paper, based on wind tunnel experiment, by studying on the vortex-induced vibration characteristics of a long-span suspension bridge with single cable plane, aerodynamic measures for easing the vortex-induced vibration are given.

scholarly journals PENELITIAN MEKANISME STALL AKIBAT PERKEMBANGAN GELEMBUNG SEPARASI PADA SAYAP NACA 0017 SECARA EKSPERIMEN DI TEROWONGAN ANGIN SUBSONIK

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Agus Aribowo
Keyword(s):  
Reynolds Number ◽  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Tunnel Experiment ◽  
Effect Mechanism ◽  
Subsonic Wind Tunnel

This paper presents the results of investigation the separation buble which growing and burst on aerofoil NACA 0017 with effect mechanism of stall in the subsonic wind tunnel. Experiment have done on wind speed 20 m per s and 30 m per s. The data pecked from the orifice of pressure with interval 2 degree until stall position. The result was separation buble which growing on the airfoil, going to ahead of airfoil together with increasing the Reynolds number. After touching, the flow appeared to separate from the upper airfoil without reattachment.

Wind tunnel experiment of long-span suspension bridge using 3D models

1991 ◽  
Vol 1991 (46) ◽  
pp. 1-17 ◽  
Author(s):  
Yozo FUJINO ◽  
Masami IWAMOTO ◽  
Manabu ITO ◽  
Yuichi HIKAMI ◽  
Katsuaki TAKEDA ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Suspension Bridge ◽  
3D Models ◽  
Wind Tunnel Experiment ◽  
Long Span

scholarly journals Structural Characteristics of Snow Drifts and Cornices

1985 ◽  
Vol 6 ◽  
pp. 287-288 ◽  
Author(s):  
Renji Naruse ◽  
Hiroshi Nishimura ◽  
Norikazu Maeno
Keyword(s):  
Grain Size ◽  
Wind Speed ◽  
Wind Tunnel ◽  
Mass Balance ◽  
Structural Characteristics ◽  
Wind Tunnel Experiment ◽  
Surface Mass Balance ◽  
Field Observations ◽  
Surface Mass ◽  
Horizontal Step

Sorting effects of snow particles during deposition were studied in field observations of snow cornices and wind-tunnel experiment of snow drifts. Grain size, density and hardness were larger at the upper part (root) of a cornice than at the lower part (scarp). Experiments with the use of a horizontal step in a wind-tunnel revealed the importance of redistribution of snow particles on the formation of drifts: at wind speed of 5 m/s, about 40% of particles fallen onto the surface behind a 0.1-m high step were removed by erosion, rebound and creep. The surface mass balance controlling the growth and shape of a drift are briefly discussed.

scholarly journals Experimental and Numerical Analysis of a Seawall’s Effect on Wind Turbine Performance

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3877 ◽  
Author(s):  
Hyun-Goo Kim ◽  
Wan-Ho Jeon
Keyword(s):  
Numerical Analysis ◽  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Flow Separation ◽  
Wind Farm ◽  
Wind Tunnel Experiment ◽  
Scale Model ◽  
Wind Flow ◽  
Cfd Analysis

For the purposes of this study, a wind tunnel experiment and a numerical analysis during ebb and high tides were conducted to determine the positive and negative effects of wind flow influenced by a seawall structure on the performance of wind turbines installed along a coastal seawall. The comparison of the wind flow field between a wind tunnel experiment performed with a 1/100 scale model and a computational fluid dynamics (CFD) analysis confirmed that the MP k-turbulence model estimated flow separation on the leeside of the seawall the most accurately. The CFD analysis verified that wind speed-up occurred due to the virtual hill effect caused by the seawall’s windward slope and the recirculation zone of its rear face, which created a positive effect by mitigating wind shear while increasing the mean wind speed in the wind turbine’s rotor plane. In contrast, the turbulence effect of flow separation on the seawall’s leeside was limited to the area below the wind turbine rotor, and had no negative effect. The use of the CFD verified with the comparison with the wind tunnel experiment was extended to the full-scale seawall, and the results of the analysis based on the wind turbine Supervisory Control and Data Acquisition (SCADA) data of a wind farm confirmed that the seawall effect was equivalent to a 1.5% increase in power generation as a result of a mitigation of the wind profile.

Comparison of wind characteristics at different heights of deep-cut canyon based on field measurement

2019 ◽  
Vol 23 (2) ◽  
pp. 219-233 ◽  
Author(s):  
Jingyu Zhang ◽  
Mingjin Zhang ◽  
Yongle Li ◽  
Chen Fang
Keyword(s):  
Wind Speed ◽  
Vertical Direction ◽  
Suspension Bridge ◽  
Longitudinal Direction ◽  
Longitudinal Component ◽  
Attack Angle ◽  
Gust Factor ◽  
Long Span ◽  
Wind Characteristic ◽  
Wind Characteristics

The typical U-shaped deep-cut canyon is widely distributed in the western mountainous areas of China, especially in Sichuan province and Yunnan province. The deep-cut canyon has the characteristics of the high drop in elevation, high-temperature difference, and complex wind environment. A 50 m high meteorological mast with a total of eight anemometers was erected in such topography, and a long-span suspension bridge will be constructed in the area where the meteorological mast is located. Based on the long-term monitor data, the wind characteristic parameters including average and fluctuating wind characteristics and coherence between different heights are investigated. The results are as follows. The dominant wind direction which depends on the topography is north–south. The attack angle of wind is mainly less than zero, and its probability distribution obeys the hypothetical Gaussian distribution. Both the increases in height of anemometer and in wind speed reduce the dispersion of the attack angle of wind. The gust factor has a similar change law of attack angle of wind. Turbulence intensities are affected by the height of the anemometer and the wind speed, and they are different from the recommended value of China Codes. In terms of turbulence integral length scale, the value increases with an increase in the height of the anemometer in the same component. The largest value occurs in the longitudinal direction and the smallest occurs in the vertical direction at the same level. The coherence between any two locations is relatively strong, and the longitudinal component is stronger than others. The measured wind power spectrum for longitudinal, lateral, and vertical wind in deep-cut canyon fits the von Kármán model better.

Badminton Performance Test of Wind Tunnel

2013 ◽  
Vol 860-863 ◽  
pp. 1517-1520
Author(s):  
Jing Hua Zhang ◽  
Ren Huang Wang ◽  
Hong Wei Yue
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Performance Test ◽  
Test System ◽  
Wind Tunnel Experiment ◽  
Hole Diameter ◽  
Classification Rule ◽  
System Software ◽  
The Impact

The badminton wind tunnel experiment quality classification was influenced by a lot of factors, such as the size of the wind tunnel wind speed Settings, the selection of the wind hole diameter size, Experiment parameter Settings of the test system software used standard and experimental error and so on. Therefore, a factorys wind tunnel experimental facility would be used by this paper, in order to make the quality of badminton, wind tunnel wind speed and wind hole diameter are researched further. Through the experiment testing, and combined with badminton wind tunnel experiment of theory knowledge, get the impact of these factors on the quality of badminton classification rule. Theoretical analysis is the same as the result of experiment, which this conclusion is indicated by the experiment that what we do. So as to choose the right wind tunnel device and system software of the test parameters Settings provide certain reference. Also the Badminton the judgment of the quality grade classification standard was provided the important reference frame by it.

scholarly journals Flutter Performance of the Emergency Bridge with New-Type Cable-Girder

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Lei Yang ◽  
Fei Shao ◽  
Qian Xu ◽  
Ke-bin Jiang
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Analysis Program ◽  
Aerodynamic Optimization ◽  
Wind Resistance ◽  
Optimal Scheme ◽  
Critical Wind Speed ◽  
Flutter Analysis ◽  
New Type ◽  
Optimization Schemes

Based on the proposed emergency bridge scheme, the flutter performance of the emergency bridge with the new-type cable-girder has been investigated through wind tunnel tests and numerical simulation analyses. Four aerodynamic optimization schemes have been developed in consideration of structure characteristics of the emergency bridge. The flutter performances of the aerodynamic optimization schemes have been investigated. The flutter derivatives of four aerodynamic optimization schemes have been analyzed. According to the results, the optimal scheme has been determined. Based on flutter theory of bridge, the differential equations of flutter of the emergency bridge with new-type cable-girder have been established. Iterative method has been used for solving the differential equations. The flutter analysis program has been compiled using the APDL language in ANSYS, and the bridge flutter critical wind speed of the optimal scheme has been determined by the program. The flutter analysis program has also been used to determine the bridge flutter critical wind speed of different wind-resistance cable schemes. The results indicate that the bridge flutter critical wind speed of the original emergency bridge scheme is lower than the flutter checking wind speed. The aerodynamic combined measurements of central-slotted and wind fairing are the optimal scheme, with the safety coefficients larger than 1.2 at the wind attack angles of −3°, 0°, and +3°. The bridge flutter critical wind speed of the optimal scheme has been determined using the flutter analysis program, and the numerical results agree well with the wind tunnel test results. The wind-resistance cable scheme of 90° is the optimal wind cable scheme, and the bridge flutter critical wind speed increased 31.4%. However, in consideration of the convenience in construction and the effectiveness in erection, the scheme of wind-resistance cable in the horizontal direction has been selected to be used in the emergency bridge with new-type cable-girder.

Experimental Investigation into Aerodynamic Stability of Narrow Steel Truss Girder Suspension Bridge

2011 ◽  
Vol 255-260 ◽  
pp. 938-941
Author(s):  
Hua Bai ◽  
Jia Wu Li
Keyword(s):  
Wind Tunnel ◽  
Geographical Location ◽  
Wind Tunnel Test ◽  
Suspension Bridge ◽  
Mitigation Measures ◽  
Aerodynamic Stability ◽  
Steel Truss ◽  
Section Model ◽  
Wind Climate ◽  
Steel Truss Girder

A narrow steel truss girder suspension bridge was designed for pedestrian and livestock in pasture in Xinjiang Province, China. For the complex wind climate at bridge site, the cautious designers resorted to wind tunnel test to confirm the aerodynamic stability of the bridge. The analysis and results from wind tunnel test conducted in Chang’an Wind Tunnel Laboratory indicated the original scheme must be changed considerably to improve the aerodynamic stability under action of wind. Considering the shape feature of Siudirgol Bridge and its geographical location, section model with such mitigation measures as auxiliary cables and central buckles were re-tested in wind tunnel joint with analysis. The auxiliary cables and central buckles can increase considerably the fundamental frequency of the bridge and hence the critical wind speed of flutter.

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