一种新型直筒-锥段型钢结构冷却塔气动性能的LES数值分析

作为一种外形新颖的典型风敏感结构,直筒-锥段型钢结构冷却塔表面风荷载随机分布特性亟待研究。以国内拟建最高的某新型直筒-锥段型钢结构冷却塔(塔高189 m)为例,采用大涡模拟(Large eddy simulation,LES)方法对其进行风场数值模拟,获取了直筒和锥段两部分结构的外表面三维气动力时程。将平均和脉动风压系数分别与相关规范及国内外冷却塔实测及风洞试验结果进行对比,验证了数值模拟方法的有效性。进而提炼出此类直筒-锥段型钢结构冷却塔外表面平均、脉动和极值风荷载以及阻力系数等气动参数分布规律。最终给出了此类新型的直筒-锥段型钢结构冷却塔结构平均和极值风压估算公式及其分布曲线。

LES Numerical Analysis on Aerodynamic Performance for Novel Steel Cooling Tower with Straight Cylinder-Cone Section

As a novel typical wind-sensitive structure, the random distribution characteristic of wind load on the surface of cylinder-conic section steel cooling tower is in an urgent need to be studied. A novel straight-cone steel cooling tower (189 m in high) that will be built at home is taken as an example, and numerical simulation of wind field is conducted by adopting large eddy simulation (LES) to obtain three-dimensional aerodynamic force time history. Firstly, the average and fluctuating wind pressure coefficients are individually compared with the relevant codes and the results from field measurements and wind tunnels at home and abroad to illustrate the validity of numerical simulation method. And then, the distribution of the average pressure, the fluctuating wind pressure, the extreme wind pressure and the drag coefficient are extracted. The estimation formulas and distribution curves of average and extreme wind pressure of cooling tower are presented. The main conclusions can be used as reference for the design of wind load of this kind of super large steel structure cooling tower with novelty in structural form.