Effect of Slope Gradient on Wind Pressure of High-Rise Buildings during Thunderstorm

To analyze the effects of thunderstorm downburst wind on the surface wind load of high-rise buildings and provide a reference for the design of high-rise buildings, the wind pressure distribution on the surface of high-rise buildings on flat and sloped terrains was investigated using an impinging jet device in wind tunnel tests. The computational fluid dynamics software FLUENT was used to simulate and supplement the test cases, analyze the characteristics of surface wind pressure on high-rise buildings over flat terrain and slope, and determine how the slope gradient affects the wind pressure on high-rise buildings. The results show that on flat terrain, the resistance coefficient distribution of each layer of a high-rise building along the vertical direction has the same changing law at different radial positions and the resistance of each layer decreases with an increase in the radial distance. For radial distances from 1.0 times the diameter of the jet nozzle to 3.0 times. the average maximum layer resistance coefficient decreased from 1.3 to approximately 0.3. The wind pressure on the building gradually decreased with an increase in the slope gradient. On slope terrain, there is negative correlation between windward pressure and the increase of the slope angle, and the height of the extreme wind pressure also decreases with the increase in the slope angle. From a flat ground to a 90° slope, the extreme wind pressure coefficient decreased by more than 0.7, and the height of the maximum wind pressure decreased from the 1/4 of building height down to the bottom of building.