基于大涡模拟直筒-锥段型钢结构冷却塔风压非高斯特性研究  

Non-Gaussian wind pressure of cylindrical-cone steel cooling tower based on large eddy simulation

作　　者：柯世堂 王浩[1] KE Shitang;WANG Hao(College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)

机构地区：[1]南京航空航天大学航空宇航学院

出　　处：《建筑结构学报》2018年第2期114-121,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(U1733129);江苏省优秀青年基金项目(BK20160083);江苏省六大人才高峰计划项目(JZ-026)

摘　　要：为研究直筒-锥段型钢结构冷却塔表面脉动风压非高斯特性,并对非高斯特性的形成机理进行分析。以国内拟建的首座超大直筒-锥段型钢结构冷却塔（189 m）为例,采用大涡模拟（LES）方法对其进行了数值风洞试验,得到其表面流场特性和压力时程,并通过与国内外大型冷却塔实测及风洞试验结果对比验证了数值模拟结果的有效性。基于典型测点概率密度分布曲线和空间相关性,对具有非高斯分布特性的局部区域给出判断标准,并从非高斯特性的形成与分离流动及涡旋运动相关性入手,揭示了非高斯风压的形成机理。研究表明：负压极值点至分离点区域内锥段和直筒段表面风压呈非高斯分布,锥段背风区风压也明显呈非高斯分布,而直筒段背风区大多测点呈高斯分布特征。With a proposed super large cylindrical-cone steel cooling tower（189 m） as an example,distribution of the non-Guassian features of fluctuating wind pressure was studied and the formation mechanism of non-Gaussian property was researched. Numerical wind tunnel test was conducted by adopting large eddy simulation（LES） method to obtain the flow field characteristics and stress time history. The simulation results were compared with the results from field measurements and wind tunnels at home and abroad,showing the rationality of LES method to obtain the wind loads on this type of cooling tower. Typical wind pressure probability density curve and histograms and aerodynamic force time history were employed to identify the local regions in which the wind pressure fluctuations exhibit non-Gaussian nature.The cause for non-Gaussian features is discussed by the correlation between non-Gaussian features and vortex motion.Research shows that： the wind pressures from the region of extreme negative pressure to the region of flow separation are largely non-Gaussian in the conical and cylindrical parts. In the leeward region,wind pressures of the cylindrical part largely obey Gaussian distribution,while the wind pressures of the conical part are generally non-Gaussian.

关 键 词：直筒-锥段型钢结构冷却塔 脉动风压 大涡模拟 非高斯特性 形成机理 

分 类 号：TU279.741[建筑科学—建筑设计及理论]