Wind tunnel test and numerical simulation of wind characteristics at a bridge site in mountainous terrain

2016 ◽  
Vol 20 (8) ◽  
pp. 1223-1231 ◽  
Author(s):  
Yongle Li ◽  
Xinyu Xu ◽  
Mingjin Zhang ◽  
Youlin Xu
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Bridge Deck ◽  
Angle Of Attack ◽  
Wind Tunnel Test ◽  
Vertical Direction ◽  
Steep Slope ◽  
Mountainous Terrain ◽  
Bridge Site ◽  
Wind Characteristics

Wind tunnel test and computational fluid dynamics simulation were conducted to study the wind characteristics at a bridge site in mountainous terrain. The upstream terrains were classified into three types: open terrain, open terrain with a steep slope close to the bridge, and open terrain with a ridge close to the bridge. Results obtained from the two methods were compared, including mean speed profiles in the vertical direction and variations of wind speed and angle of attack along the bridge deck. In addition, turbulence intensities at the bridge site obtained from wind tunnel test were discussed. For mean speed profiles in the vertical direction, two methods are reasonably close for open terrain, while mountain shielding effects are evident for open terrain with a steep slope for both the methods, but the extents of effects appear different. Wind speed and angle of attack along the bridge deck are mainly influenced by the local terrain. Strong downslope wind is generated at the lee slope for the case of wind normal to top of the ridge. The comparative results are expected to provide useful references for the study of wind characteristics in mountainous terrain in the future.

scholarly journals Experimental and Numerical Investigation of Wind Characteristics over Mountainous Valley Bridge Site Considering Improved Boundary Transition Sections

2020 ◽  
Vol 10 (3) ◽  
pp. 751 ◽  
Author(s):  
Xiangyan Chen ◽  
Zhiwen Liu ◽  
Xinguo Wang ◽  
Zhengqing Chen ◽  
Han Xiao ◽  
...  
Keyword(s):  
Wind Speed ◽  
Experimental Investigations ◽  
Maximum Relative Error ◽  
Mountainous Terrain ◽  
Bridge Site ◽  
Terrain Model ◽  
Cross Bridge ◽  
Wind Characteristics ◽  
The Cross ◽  
Bridge Length

To study wind characteristics over mountainous terrain, the Xiangjiang Bridge site was employed in this paper. The improved boundary transition sections (BTS) were adopted to reduce the influence of “artificial cliffs” of the terrain model on the wind characteristics at the bridge site over the mountainous terrain. Numerical simulation and experimental investigations on wind characteristics over mountainous terrain with/without BTS were conducted for different cases, respectively. The research results show that the cross-bridge wind speed ratios and wind attack angles at the main deck level vary greatly along the bridge axis, which can be roughly divided into three parts, namely the mountain (I, III) and central canyon areas (II). The cross-bridge wind speed ratios at the main deck level with BTS is generally larger than that without BTS in the central canyon area (II) for most cases, while the opposite trend can be found in wind attack angles. The longitudinal wind speed ratios of the terrain model with BTS at L/4, L/2, and 3L/4 of the bridge length are larger than that of the terrain model without BTS for most cases. In general, the maximum relative error between numerical results and experimental results is about 30% for most cases.

Wind Tunnel Test and the Analysis of Buffeting Performance of Free-Standing Tower of Cable-Stayed Bridge under Yaw Wind

2012 ◽  
Vol 532-533 ◽  
pp. 215-219
Author(s):  
Guo Hui Zhao ◽  
Yu Li ◽  
Hua Bai
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Free Standing ◽  
Buffeting Response ◽  
Cable Stayed Bridge ◽  
Aeroelastic Model ◽  
Navigation Channel ◽  
Yaw Angle

The buffeting performance of free-standing tower of JiangHai Navigation Channel Bridge, a cable-stayed bridge, under yaw wind is investigated by means of wind tunnel test of aeroelastic model. It is found that the variation of buffeting response of free-standing tower with wind yaw angle is not monotonous. The lateral buffeting response on the top of the free-standing tower reach their minimal values and maximal values at around 150°and 180°of wind yaw angle respectively and the longitudinal buffeting response attain their maximal values at around 90°of wind yaw angle. Also, at the 2/3 height of the tower the lateral buffeting response and torsional buffeting response get their minimal values at around 150°of wind yaw angle, and at around 180°achieve the maximal values. It is also seen that, the buffeting response changes with the wind speed at a conic curve approximately.

scholarly journals Galloping Stability and Aerodynamic Characteristic of Iced Transmission Line Based on 3-DOF

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaohui Liu ◽  
Ming Zou ◽  
Chuan Wu ◽  
Bo Yan ◽  
Mengqi Cai
Keyword(s):  
Wind Speed ◽  
Transmission Line ◽  
Angle Of Attack ◽  
Wind Tunnel Test ◽  
Simulation Method ◽  
Theoretical Formula ◽  
Aerodynamic Load ◽  
Line System ◽  
Critical Wind Speed ◽  
The Stability

A new calculation method of critical wind speed based on three degrees of freedom (3-DOF) is proposed for galloping problem of iced transmission line. Based on the quasistatic theory, the aerodynamic load of iced transmission line is obtained, which considers the influence of transverse and torsional motion on the relative wind angle of attack. Finally, the equivalent galloping model of 3-DOF iced transmission line is established. At the initial angle of attack, the aerodynamic load is expanded by Taylor, and the unsymmetrical linear aerodynamic coefficient matrix is obtained. The Routh–Hurwitz criterion is used to judge the stability of iced transmission line system, and then the critical wind speed is calculated. The in-plane and out-plane frequencies corresponding to the first-order mode of the transmission line are solved by the analytical method and numerical simulation method. The results obtained by the two methods are compared and verified. The influence of dimensionless transmission line parameter λ on the in-plane and out-of-plane frequencies is discussed. The aerodynamic coefficients of the iced transmission line are measured by wind tunnel test and the aerodynamic characteristics are analyzed. According to the theoretical formula, the critical wind speed is calculated by MATLAB. The critical wind speed determined in this paper is compared with the critical wind speed determined by Den Hartog and Nigol theory. The influences of torsional vibration frequency, ice thickness, and ice shape on critical wind speed are analyzed. The research results of this paper have important theoretical significance for the stability judgment of iced transmission lines.

Influence of elevated water levels on wind field characteristics at a bridge site

2019 ◽  
Vol 22 (7) ◽  
pp. 1783-1795 ◽  
Author(s):  
Hongmiao Jing ◽  
Haili Liao ◽  
Cunming Ma ◽  
Kejian Chen
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Water Level ◽  
Wind Field ◽  
Wind Profile ◽  
Water Levels ◽  
Bridge Engineering ◽  
Bridge Site ◽  
Bridge Girder ◽  
Elevated Water

The influence of elevated water levels on wind field characteristics at bridge sites owing to hydroelectric power stations plays an important role in bridge engineering, particularly in mountainous valley regions. To investigate this issue, a comparative experimental study, which uses a topographic model with two water level states for determining the influence on wind field characteristics at the proposed bridge site located in a mountainous valley area, was conducted in the XNJD-3 wind tunnel at Southwest Jiaotong University, Chengdu, PR China. The altitude difference between the two water level states was approximately 200 m, whereas uniform and D-type boundary layer air inflow conditions were adopted during the wind tunnel test, respectively. The wind speed at the bridge girder and profile of the 1/4, mid, and 3/4 spans were recorded during the experiment. The test results indicated that after the water level was raised, the mean wind speed (or speed-up factor) along the bridge girder decreased by approximately 10%, and the values of the wind profile also decreased. However, the wind profile curve shapes remained approximately unchanged, and the wind attack angle was significantly transformed by approximately 5° in certain locations of the bridge girder. Moreover, the variation in the water level had a negligible influence on the turbulence intensities, turbulence integral length scales, probability distribution of fluctuating wind components, and turbulent wind spectra along the bridge girder. Therefore, as the water level in the canyon rises, the wind field characteristics at the bridge site tend to be conducive to bridge safety. Therefore, long-span bridges located in mountainous valley areas should be designed appropriately according to the expected minimum water level of the river.

scholarly journals Wind Turbine Wake Modeling in Accelerating Wind Field: A Preliminary Study on a Two-Dimensional Hill

Fluids ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 153 ◽  
Author(s):  
Omar M. A. M. Ibrahim ◽  
Shigeo Yoshida ◽  
Masahiro Hamasaki ◽  
Ao Takada
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Wind Field ◽  
Complex Terrain ◽  
Wind Farm ◽  
Wind Tunnel Test ◽  
Two Dimensional ◽  
Preliminary Study ◽  
Wake Model

Complex terrain can influence wind turbine wakes and wind speed profiles in a wind farm. Consequently, predicting the performance of wind turbines and energy production over complex terrain is more difficult than it is over flat terrain. In this preliminary study, an engineering wake model, that considers acceleration on a two-dimensional hill, was developed based on the momentum theory. The model consists of the wake width and wake wind speed. The equation to calculate the rotor thrust, which is calculated by the wake wind speed profiles, was also formulated. Then, a wind-tunnel test was performed in simple flow conditions in order to investigate wake development over a two-dimensional hill. After this the wake model was compared with the wind-tunnel test, and the results obtained by using the new wake model were close to the wind-tunnel test results. Using the new wake model, it was possible to estimate the wake shrinkage in an accelerating two-dimensional wind field.

scholarly journals Wind tunnel investigation on the dust emission characteristics of high moisture coal piles

2020 ◽  
Vol 145 ◽  
pp. 02019
Author(s):  
Ningning Hong ◽  
Shitao Peng ◽  
Hongxin Zhao ◽  
Ning Su
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Moisture Content ◽  
Coal Dust ◽  
Dust Emission ◽  
Wind Tunnel Test ◽  
High Moisture Content ◽  
High Moisture ◽  
Emission Behavior ◽  
The Relationship

With the increasing requirements of environmental protection, a large number of new wet dust suppression technologies are used in the port in recent years, such as watering at the bottom of the Dumper Shed, etc. So the moisture content of coal is more than 10% often appear. Relevant studies show that the amount of dust from coal (conventional moisture content) pile is directly proportional to the high power of wind speed. But studies on high moisture content coal are rare. In this study, Wind tunnel test was carried out to study the dust emission behavior of coal with high moisture content (13.7% and 14.3%). The results show that the relationship between coal dust and wind speed tends to be linear under high moisture content. The study can provide a basis research for the estimation of coal dust emission in port.

A Study on the Target 2D Tracking Analysis Using Digital Image Correlation at Bridge Deck Wind Tunnel Test

2012 ◽  
Vol 18 (1) ◽  
pp. 2127-2135
Author(s):  
Seung-Taek Oh ◽  
Nak-Hyun Chun ◽  
Seung-Young Yoo ◽  
Ho-Yeop Lee ◽  
Hak-Eun Lee
Keyword(s):  
Wind Tunnel ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Bridge Deck ◽  
Wind Tunnel Test ◽  
Image Correlation

scholarly journals Evaluation of Wind-Induced Response Bounds of High-Rise Buildings Based on a Nonrandom Interval Analysis Method

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Xianglei Wei ◽  
An Xu ◽  
Ruohong Zhao
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Wind Load ◽  
Upper And Lower Bounds ◽  
Induced Response ◽  
Response Analysis ◽  
Analysis Method ◽  
High Rise ◽  
Interval Analysis Method

The traditional wind-induced response analysis of high-rise buildings conventionally considers the wind load as a stationary stochastic process. That is, for a certain wind direction angle, the reference wind speed (usually refers to the mean wind speed at the building height) is assumed to be a constant corresponding to a certain return period. Combined with the recorded data in wind tunnel test, the structural response can be computed using the random vibration theory. However, in the actual typhoon process, the average wind speed is usually time-variant. This paper combines the interval process model and the nonrandom vibration analysis method with the wind tunnel test and proposes a method for estimating the response boundary of the high-rise buildings under nonstationary wind loads. With the given upper and lower bounds of time-variant wind excitation, this method can provide an effective calculation tool for estimating wind-induced vibration bounds for high-rise buildings under nonstationary wind load. The Guangzhou East tower, which is 530 m high and the highest supertall building in Guangzhou, China, was taken as an example to show the effectiveness of the method. The obtained boundary response can help disaster prevention and control during the passage of typhoons.

Design of a Wind Tunnel Test Section for Single Airfoil Configuration With Real-Time Lift Force Control

2017 ◽  
Author(s):  
Aline Aguiar da Franca ◽  
Dirk Abel
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Real Time ◽  
Force Control ◽  
Test Section ◽  
Lift Force ◽  
Angle Of Attack ◽  
Wind Tunnel Test ◽  
Wiener Model ◽  
Dynamic Matrix

This article presents a concept of test section for a closed-return wind tunnel, where the lift force of an airfoil, which depends on the angle of attack, is controlled in real-time. This airfoil is used to represent a wind turbine blade. The lift force of the blades is what produces the rotor torque of the wind turbine. This torque determines the amount of energy that will be captured by the wind turbine. The linear dynamics of the motor used to change the angle of attack and the static non-linearity of the airfoil are modeled as a Wiener model. The Quadratic Dynamic Matrix Controller based on Wiener model with linearizing pre-compensation is implemented to keep the lift force constant, which is desirable to avoid mechanical loads for wind turbine applications.

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