摘要:
在流线型结构气动性能风洞试验研究中,结构表面绕流特征雷诺数效应的准确模拟对于确定风荷载、评价其气动性能的影响是决定性的.通过改变模型表面粗糙度可以实现原型结构超高雷诺数条件(Re≥10~7)绕流效应模拟,但模拟手段及效果受人为经验因素影响较大,难于总结表面粗糙度与绕流形态变化关系,给实际模拟操作造成不便.设计两组双曲线圆截面结构模型风洞试验,通过在模型表面粘贴不同厚度粗糙纸带的办法,尝试并实现了模型超高雷诺数条件绕流特征模拟,分析了粗糙度及试验风速对模型表面绕流压力分布、截面阻力系数等参数的影响,初步总结了相对粗糙度随模型尺度的变化规律,为更好展开圆截面建筑结构气动性能研究提供了借鉴.
Abstract:
In wind tunnel tests,the Reynolds number plays a crucial role in the evolution of the flows around streamlined structures which determines the evaluation of its wind loading and aerodynamic performances.Previous works suggests the effects of high Reynolds number can be simulated by increasing the surface roughness,but the effects of the simulations are usually influenced by artificial factors.Little is known about the relationship between surface roughness and the change of flow features which makes the practical simulations difficult.Two comparative wind tunnel tests of Hyperbolic circular section structures in difficult Reynolds number range were designed.By changing the thickness of the strips on the model surfaces,the effects of high Reynolds numbers were simulated,including the investigation of both transverse pressure distribution and drag coefficient.A serial of results provide a detailed understanding of the regularity of surface roughness parameters with different model scales,which helps the practices of similar future projects.
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