The Research Of Thunderstorm Downbursts And Its Effect On Solar Chimney Structures

Thunderstorm downburst, as extreme wind, Wind profiles and characteristics in athunderstorm downburst are significantly different from that of regular boundary layerwinds. The velocity of thunderstorm wind on the ground initially increases to a maximumnear the ground and drops from the ground, thunderstorm downbursts can damage highsolar chimney structures. Therefore, the design of high solar chimney structures isgoverned by wind loadsA commercially available Computational Fluid Dynamics (CFD) software, Fluent, isemployed to simulate wind field characteristics of thunderstorm downbursts and its affecton high solar chimney structures. Using axisymmetric numerical simulation, weresearched the characteristics of wind velocity profiles and turbulence intensity profiles.According to the simulation results, we find the position when the max velocity arrived ofthe wind field, also the fitting model for turbulence intensity profiles along height isestablished.Pressure characteristics on high solar chimney structures of downburst are researched.When the downburst occurs, vortex is formed around the chimney. The pressuredistribution curve and the range of pressure at different time and different height areapproached. Studies have shown that the pressure on the bottom of chimney is higher thanthat on the upper.Pressure characteristics on high solar chimney structures of moving downburst arealso researched, utilizing User Define Function (UDF) to simulate dynamic characteristic.The results show that the time histories of wind pressures at the points around the circularsurface are complex due to the moving of stagnation points. The findings provide somebasis of the design of high solar chimney structures.