以某规划中的235m超大型冷却塔1:200刚性模型测压风洞试验为基础,对超大型冷却塔缩尺模型模拟高雷诺数条件下的动态荷载效应进行了细致研究,得到了一些有借鉴性的结论:(1)模型表面粗糙度对雷诺数效应的作用受来流条件的影响显著;(2)冷却塔缩尺模型风洞试验应优先选用较高的试验风速;(3)最优模拟措施的选择应综合考虑特征断面的风压均值、根方差分布及阻力系数和斯脱罗哈数等参数;(4)圆柱体的“斯托罗哈数一雷诺数关系曲线”是否完全适用于变截面的双曲圆截面冷却塔,需要通过超大型冷却塔风压实测进行验证。
The flow characteristics around the hyperbolic cooling tower model with circular cross section in the wind tunnel experiments are sensitive to Reynolds number. How to get the accurate Reynolds number effects in the wind tunnel tests for super large cooling towers is still a tough task for structural wind engi- neers. Up to now, engineers have not been able to get the precise values of some dynamic characteristic pa- rameters induced by fluctuating wind due to the shortcomings of early quasi-dynamic sensors. Meanwhile, it is noted that these parameters play important roles in the design process of super large cooling towers which are higher than 165m. This research is based on a 235m high super large cooling tower on the planning. By external pressure wind tunnel tests of the rigid model with scale of 1 : 200, a detailed study on the super high Reynolds number effects of the tower are carried out and some valuable conclusions are gotten after the tests. (1) The influence of the surface roughness to Reynolds numbers effects is sensitive to the flow characteris- tics; (2) The higher wind speed should be firstly chosen in the wind tunnel tests on the same condition; (3) The best simulation measurements should consider the distribution of mean and fluctuating wind pressures of the model's critical sections, drag coefficients and Strouhal number together; (4) Whether the Strouhal num- ber-Reynolds numbers curve of circular cylinder is suitable to super large hyperbolic cooling towers with changing sections in altitude direction should be checked by field tests in the future.