Numerical simulation of distribution characteristic of wind fields and terrain’s influence in mountain canyon(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年05期
- Page:
- 56-64
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Numerical simulation of distribution characteristic of wind fields and terrain’s influence in mountain canyon
- Author(s):
- HONG Xin-min; GUO Wen-hua; XIONG An-ping
- School of Civil Engineering, Central South University, Changsha 410004, Hunan, China
- Keywords:
- bridge engineering; spatial distribution characteristic; canyon terrain; wind speed magnification coefficient; computation fluid dynamics
- PACS:
- U442.4
- DOI:
- -
- Abstract:
- In order to reveal the spatial distribution characteristics of wind fields in mountain canyon and the effect of canyon topography on the distribution characteristics of wind field in valley, according to the topographic features of mountain valleys, the digital geometry of canyon was discreted into elevation points in AutoCAD, and the elevation points were used to synthesize the canyon terrain and surface by using reverse engineering software Imageware, which were imported into Gambit to generate computational models that meet the requirements. The Realizable model suitable for mountain wind field and the SIMPLE algorithm with good stability were selected to numerically simulate the wind field characteristics of canyon by FLUENT software. Finally, according to the characteristic of canyon topography and influencing parameter velocity amplification coefficient mathematical formulas of canyon wind were put forward, and its validity was proved by multiple calculating examples. The results show that the contour line of canyon wind profiles can be divided into three segmentations, and it cannot be simulated by the power function model that is frequently used in plain area. Moreover, the contour of canyon wind profile has obvious inflection point, and the contours of wind profile in wind increasing section should be simulated by linear function and power function. The maximum wind velocity of wind profile in middle of the canyon is greater than the maximum wind speed at both sides of the canyon, and the corresponding wind speed inflection point’s height is also higher. The wind speed at the same height observation point in the canyon is parabola in the cross section of canyon, and the wind speed reaches the maximum value at the distance of about 60 m between the two sides of the mountain. The smaller the canyon width, the higher the peak in both sides, and the more obvious the “valley effect” of wind fields in valley. The wind speed inflection point height of wind profile is inversely proportional to the canyon depth-width ratio, and the greater the depth-width ratio of the canyon, the smaller the inflection height. The formulas in this paper can be used to calculate the wind speed of any height point in mountain canyon, and it provides a simple method for calculating the wind-resistant design wind speed of bridge in mountain canyon.
Last Update: 2017-10-16