Wind Speed Profiles of an Actual Downburst Based on CFD Numerical Simulation

Abstract:

Downbursts have led to large number of transmission tower failures in the world, so more and more wind engineers are very interested in such strong wind load. Currently the main numerical simulation method of downburst wind load for structural analysis is based on the horizontal divergent wind speed profile of downburst. There have been several available types of empirical wind speed profiles in which some parameters still need to be artificially determined. So, this is a semi-empirical-analytical method which can not be linked with actual downbursts. Some academics have also used CFD numerical method to simulate downburst wind speed profile of high precision grid. But the initial conditions of these CFD simulations were all assumed ideally. In this paper, the wind speed profiles of an actual downburst are simulated by CFD method based on the initial speed of downdraft entrance provided by cloud model. The simulated wind speed profile decays more slowly than an empirical wind speed profile. This conclusion could be of significance for structural engineers to consider downburst wind load reasonably in the structural wind resistant design.

• Periodical: Applied Mechanics and Materials (Volumes 170-173)
• Pages: 3411-3414
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.170-173.3411
• Online since: May 2012
• Authors: Yan Li, Wei Lian Qu, Bai Feng Ji, Yi Fei Wang
• Keywords: CFD Numerical Simulation, Downburst, Wind Speed Profiles

References

[1] D Dempsey, H White. Winds wreak havoc on lines[J]. Transmission and Distribution World, 1996, 48(6):32-37.

[2] FLUENT User's Guide, Release 6.2, Fluent Inc., Lebanon, New Hampshire, 2005.

[3] Y.Li, W.L.Qu, B.Wang, Y.F. Wang and B.F.Ji. Three-Dimension Numerical Simulation of Downburst Wind Occurred in Wuhan[J], Advanced Materials Research.Vols.243-249 (2011) pp.5037-5040.

DOI: 10.4028/www.scientific.net/amr.243-249.5037

[4] DDVicroy. Assessment of microburst models for downdraft estimation[J]. Journal of Aircraft , 1992, 29:1043-1048.

DOI: 10.2514/3.46282

[5] Weilian Qu, Baifeng Ji, Jianqun Li, et al. The study on numerical simulation of downburst wind. Earthquake Engineering and Engineering Vibration[J], 2008(5):133-139(in chinese).