大气边界层风洞流场特性的模拟

风洞中大气边界层模拟的准确度是保证风洞试验结果准确度的重要因素。本文采用了一种新型曲边梯形尖塔,并结合粗糙元等被动装置对风洞大气边界层模拟进行了研究,模拟出我国规范中的A、B、C和D类四种地貌并将结果和已有的研究结果进行比较。结果显示：所采用新型结构尖塔可以显著提高风洞大气边界层中部以上高度的湍流度,整个湍流度剖面基本覆盖了西方主要国家规范对此项指标的建议值。文中还调试出平均风速剖面不变而湍流度分布可变的流场,为开展相关的结构抗风研究奠定了基础。

Wind tunnel simulation of atmospheric boundary layer

The simulation of atmospheric boundary layer using spires and a fetch of roughness elements is discussed in light of experiments carried out to reproduce the characteristics of a boundary layer for the four types of terrains. An improved spire configuration is adopted for the simulation of atmospheric boundary layer. Compared with the results simulated in other wind tunnels which use the delta spires, it shows that the new type of spires produce higher turbulence intensity onthe higher area of atmospheric boundary layers. For the each type of terrain, the reproduced turbulence intensity profile covers provisions suggested by some major national codes. A set of flow fields, which have the same mean velocity profile but the different turbulence intensity profiles, are simulated successfully in the wind tunnel. In this way, the influence of turbulence on the structure can be studied in the same terrain.