Numerical Simulation of Flow over Mountainous Valley Terrain

2012 ◽  
Vol 204-208 ◽  
pp. 3369-3372
Author(s):  
Chun Guang Li ◽  
Zheng Qing Chen ◽  
Zhi Tian Zhang
Keyword(s):  
Numerical Simulation ◽  
Hunan Province ◽  
Mountainous Area ◽  
Mean Flow ◽  
Long Span ◽  
Long Span Bridge ◽  
Roughness Exponent ◽  
Speed Up ◽  
Design Wind Speed ◽  
The Mean

With the increase of the span length of bridge, the wind field characteristics at bridge site play crucial role for the safety of bridge. The present paper discusses the results of a numerical simulation of the wind flow over mountainous area called Aizhai, located in Hunan province, where a super long span bridge with main span of 1176m will be constructed. The results indicate that it is inappropriate to describe the mean wind velocity profiles by power law using the same roughness exponent along the span wise direction in the mountainous valley terrain. The speed-up effect and the significant change in wind direction of the mean flow were observed, which provide the information necessary for determining the design wind speed such as for a long span bridge across the valley.

Multiscale simulation of wind field on a long-span bridge site in mountainous area

2018 ◽  
Vol 177 ◽  
pp. 260-274 ◽  
Author(s):  
Yan Han ◽  
Lian Shen ◽  
Guoji Xu ◽  
C.S. Cai ◽  
Peng Hu ◽  
...  
Keyword(s):  
Wind Field ◽  
Multiscale Simulation ◽  
Mountainous Area ◽  
Bridge Site ◽  
Long Span ◽  
Long Span Bridge

Numerical Simulation of Wind-Driven Rain on a Long-Span Bridge

2019 ◽  
Vol 19 (12) ◽  
pp. 1950149
Author(s):  
Shenghong Huang ◽  
Qiusheng Li ◽  
Man Liu ◽  
Fubin Chen ◽  
Shun Liu
Keyword(s):  
Numerical Simulation ◽  
Wind Engineering ◽  
Multiphase Model ◽  
Rain Intensity ◽  
Long Span Bridges ◽  
Long Span ◽  
Long Span Bridge ◽  
Extreme Rain ◽  
Section Model ◽  
Bridge Spans

Wind-driven rain (WDR) and its interactions with structures is an important research subject in wind engineering. As bridge spans are becoming longer and longer, the effects of WDR on long-span bridges should be well understood. Therefore, this paper presents a comprehensive numerical simulation study of WDR on a full-scale long-span bridge under extreme conditions. A validation study shows that the predictions of WDR on a bridge section model agree with experimental results, validating the applicability of the WDR simulation approach based on the Eulerian multiphase model. Furthermore, a detailed numerical simulation of WDR on a long-span bridge, North Bridge of Xiazhang Cross-sea Bridge is conducted. The simulation results indicate that although the loads induced by raindrops on the bridge surfaces are very small as compared to the wind loads, extreme rain intensity may occur on some windward surfaces of the bridge. The adopted numerical methods and rain loading models are validated to be an effective tool for WDR simulation for bridges and the results presented in this paper provide useful information for the water-erosion proof design of future long-span bridges.

scholarly journals Numerical Simulation of Characteristics of Wind Field at Bridge Sites in Flat and Gorge Terrains under the Thunderstorm Downburst

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Peng Hu ◽  
Yilin Chen ◽  
Yan Han ◽  
Fei Zhang ◽  
Yongjian Tang
Keyword(s):  
Numerical Simulation ◽  
Wind Field ◽  
Wind Fields ◽  
Monitoring Point ◽  
Wind Speeds ◽  
Flat Terrain ◽  
Long Span ◽  
Long Span Bridge ◽  
Bridge Girder ◽  
Large Wind

To investigate the effects of thunderstorm downburst on the characteristics of wind field at bridge sites in flat and gorge terrains, firstly, numerical simulation of wind fields in the flat terrain under the thunderstorm downburst was conducted through the SST k-ω turbulence model, combined with the impinging jet technology. After verification of the reliability of the numerical model, settings, and methods, the characteristics of wind field over a long-span bridge site in a gorge terrain under the thunderstorm downburst were investigated and the distributions of wind speed and wind attack angle in the flat and gorge terrains were compared. The results show that, under the effects of the thunderstorm downburst, the wind speeds are relatively maximum at the midspan point of the girder in the flat terrain. Besides, the farther away from the midspan point, the smaller the wind speeds, which is opposite to the case in the gorge terrain. The wind speeds at each typical monitoring point are basically the same in the two terrains, before the thunderstorm downburst hits the bridge girder. Later the wind speeds at each point in the gorge terrain are much higher than those in the flat terrain. Most wind attack angles are negative at the monitoring points in the flat terrain, but the farther away they are from the midspan point, the greater the wind attack angles will be. However, the wind attack angles at the monitoring points in the gorge terrain are generally larger than those in the flat terrain, and they gradually turn to be positive farther away from the midspan point. In the flat terrain, both wind speeds and wind attack angles (or their absolute values) at the girder are large within about t = 75∼130 s, indicating that the thunderstorm downburst may exert significant effects on the bridge. However, in the gorge terrain, due to the large wind speeds and wind attack angles (or their absolute values) at the girder after t = 75 s, full attention needs to be paid to the effects of the thunderstorm downburst during this period.

Research on Design and Construction of Continuous Rigid Frame Bridge in Canyon Area

2012 ◽  
Vol 178-181 ◽  
pp. 2539-2542
Author(s):  
Jing Rong Peng ◽  
Tian Hua Jiang ◽  
Yi Peng ◽  
Qing Ping Jin
Keyword(s):  
Mountainous Area ◽  
Thin Wall ◽  
Construction Methods ◽  
Long Span ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Long Span Bridge ◽  
The Future ◽  
Rigid Frame Bridge ◽  
Design And Construction

One high piers and long-span bridge in mountainous area is designed as three-span which is 106+200+106 meters. The superstructure is pre-stressed concrete continuous rigid frame, and the sub-structure is hollow thin wall piers among which the highest is 167 meters. Under the background of this bridge, this paper mainly introduces the designing and construction methods of high piers and long-span continuous rigid frame bridge in canyon area, with the expectation to be served as reference to design the similar bridges in the future.

Design and Optimization of Concrete-Filled Steel Tube Arch Bridge Using Cable-Hoisting Method

2011 ◽  
Vol 255-260 ◽  
pp. 896-900
Author(s):  
Xiao Fei Liang ◽  
Yue Xu ◽  
Hong Jing Du
Keyword(s):  
Steel Tube ◽  
Hunan Province ◽  
Construction Technology ◽  
Systematic Analysis ◽  
Arch Bridge ◽  
Design And Optimization ◽  
Long Span ◽  
Long Span Bridge ◽  
Cfst Arch Bridge ◽  
Hoisting System

Based on the hoisting construction feature of large hinge-support tower and field circumstance, the cable hoisting system for Meng-dong river grand bridge at the west of Hunan province is designed. Studying on cable hoisting system design and construction of the CFST arch bridge, the paper takes systematic analysis and calculations on the key construction technology of the CFST arch bridge, and puts it in practice successfully which provides experience for the similar long—span bridge construction of the follow.

scholarly journals The Icing Distribution Characteristics Research of Tower Cross Beam of Long-Span Bridge by Numerical Simulation

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5584
Author(s):  
Zhi-Yong Yang ◽  
Xiang Zhan ◽  
Xin-Long Zhou ◽  
Heng-Lin Xiao ◽  
Yao-Yao Pei
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Distribution Characteristics ◽  
Ice Melting ◽  
Long Span ◽  
Numerical Simulation Method ◽  
Long Span Bridge ◽  
Ice Accretions ◽  
The Cross ◽  
Windward Surface

The cross beam of a long-span bridge will freeze in low temperature. When the temperature rises, the ice on the cross beam will thaw and fall off. If the ice is too heavy, it may cause vehicle damage and casualty. In order to reduce the risk of falling ice, a scale model of the cross beam was taken as an example, and a kind of numerical simulation method is presented to study the icing distribution characteristics on surface of the cross beam. This paper simulates the ice accretions process of the cross beam by Fluent module and FENSAP-ICE module of ANSYS and investigates the influence of wind and temperature in the process. This is a new numerical simulation method for studying ice accretions of buildings. The results indicate that water freezes mainly on the windward surface, and the thicker ice is near the top and bottom edge of windward surface. According to the results of numerical simulation, a measure of ice melting based on electric heating method is proposed in this paper, and the feasibility and effectiveness of this method are verified by numerical simulation. The results show that the icing distribution characteristics are accord with the fact and the ice-melting measure is feasible and effective.

Direct numerical simulation of turbulent duct flow with inclined or V-shaped ribs mounted on one wall

2021 ◽  
Vol 932 ◽  
Author(s):  
S.V. Mahmoodi-Jezeh ◽  
Bing-Chen Wang
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Secondary Flows ◽  
Wall Turbulence ◽  
Spanwise Direction ◽  
Duct Flow ◽  
Mean Flow ◽  
Square Duct ◽  
Turbulence Structures ◽  
The Mean

In this research, highly disturbed turbulent flow of distinct three-dimensional characteristics in a square duct with inclined or V-shaped ribs mounted on one wall is investigated using direct numerical simulation. The turbulence field is highly sensitive to not only the rib geometry but also the boundary layers developed over the side and top walls. In a cross-stream plane secondary flows appear as large longitudinal vortices in both inclined and V-shaped rib cases due to the confinement of four sidewalls of the square duct. However, owing to the difference in the pattern of cross-stream secondary flow motions, the flow physics is significantly different in these two ribbed duct cases. It is observed that the mean flow structures in the cross-stream directions are asymmetrical in the inclined rib case but symmetrical in the V-shaped rib case, causing substantial differences in the momentum transfer across the spanwise direction. The impacts of rib geometry on near-wall turbulence structures are investigated using vortex identifiers, joint probability density functions between the streamwise and vertical velocity fluctuations, statistical moments of different orders, spatial two-point autocorrelations and velocity spectra. It is found that near the leeward and windward rib faces, the mean inclination angle of turbulence structures in the V-shaped rib case is greater than that of the inclined rib case, which subsequently enhances momentum transport between the ribbed bottom wall and the smooth top wall.

Wind Field Numerical Simulation of Long-Span Bridge

2013 ◽  
Vol 361-363 ◽  
pp. 1094-1100
Author(s):  
Jian Guo ◽  
Wei Chang Gan ◽  
Ding Yu Jiang ◽  
Bing Nan Sun ◽  
Wei Peng
Keyword(s):  
Numerical Simulation ◽  
Wind Field ◽  
Simulation Method ◽  
Filter Method ◽  
Linear Filter ◽  
Wind Field Simulation ◽  
Long Span ◽  
Long Span Bridge ◽  
Target Spectrum ◽  
Main Girder

In the research on calculation of interaction of wind and structure, the key to the question is wind field numerical simulation. This paper introduces a practical wind field simulation method of long-span Bridge. The main bridge of Jintang Bridge was analyzed as engineering example, which is a cross-sea cable stayed bridge in Zhoushan of Zhejiang Province , and the linear filter method was applied to calculate along-wind and vertical wind field on main girder, MATLAB program also was adopted to simulate wind field of long-span Bridge. The results show that simulated spectrum is in better agreement with the target spectrum, which verifies validity of the method and correctness of the program.

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