动网格模拟风振对超大瘦高型冷却塔风荷载的影响

Effects of wind-induced vibration on the pressure distribution of cooling tower using dynamic mesh method

利用Fluent软件对超大瘦高型冷却塔的风荷载进行了CFD数值模拟,获得冷却塔外表面的三维流场特性和风压系数分布曲线,并与规范数据进行比较,以验证数值模拟的准确性;利用CFD动网格研究风振条件下冷却塔内外壁的风压分布。结果表明:考虑风振特性后,冷却塔外壁风压呈现增大的趋势,最大负压位置即流动分离点在考虑风振时产生了滞后;对于本文研究的上下开口结构而言,在考虑风振作用后内部风压系数的绝对值整体偏大,且内部高压区的位置发生了变化;不考虑风振时内部风压高压区发生在接近塔底的区域,而考虑风振特性后,内部风压高压区发生在接近塔顶的区域。这说明风振在一定程度上改变了冷却塔内部风压的分布。

The Fluent software is used to simulate the wind load distribution of cooling tower. The results of three-dimensional flow field characteristics and pressure coefficients are compared with standardized data to verify the accuracy of the numerical simulation method. Effect of wind-induced vibration on pressure distribution of both internal and external walls of the tower is studied by using dynamic mesh method. Results obtained show that the pressure distribution of the external wall had an increasing tendency after involving vibration and the position of this maximum value where flow seperation occured is delayed to the downstream. For the special structure studied in this paper, the absolute value of pressure distribution of the internal wall is increased after involving vibration, and the change of the internal high pressure zone is observed, which occured near the bottom of the tower when omitting the wind-induced vibration, but it occured near the top of the tower when involving the wind-induced vibration. These results illustrate that wind-induced vibration changed the distribution of the internal pressure of the cooling tower to a certain extent.