风雨耦合下大型冷却塔流场特性与表面气动力  

Flow Field Characteristics and Surface Aerodynassmic Force of Large Cooling Tower Under Coupling of Wind and Rain

作　　者：余文林[1,2] 柯世堂 YU Wenlin;KE Shitang(College of Civil Aviation/College of Flight,Nanjing University of Aeronautics&Astronautics,Nanjing,211106,China;China Energy Engineering Group Jiangsu Power Design Institute Co.,LTD,Nanjing,211102,China)

机构地区：[1]南京航空航天大学民航/飞行学院,南京211106 [2]中国能源建设集团江苏省电力设计院有限公司,南京211102

出　　处：《南京航空航天大学学报》2020年第4期666-674,共9页Journal of Nanjing University of Aeronautics & Astronautics

基　　金：国家自然科学基金NSFC-RGC合作研究(51761165022)资助项目;国家自然科学基金(51208254)资助项目;江苏省优秀青年基金(BK20160083)资助项目;江苏省六大人才高峰层次人才计划(JZ-026)资助项目;江苏高校优势学科建设工程资助项目。

摘　　要：现行冷却塔结构抗风设计均忽略了降雨带来的影响,但在强风暴雨极端气候条件下,暴雨亦会直接影响塔筒内、外表面气动力并改变脉动风的湍流效应,而传统研究大多仅关注风驱动雨对于结构表面的冲击效应。为解决该问题,以国内已建世界最高220 m大型冷却塔为例,以风-雨双向耦合算法为核心,首先采用计算流体动力学(Computational fluid dynamics,CFD)技术对冷却塔周围风场进行数值模拟,并将表面风压分布与规范及实测曲线进行对比验证了风场模拟的有效性;再添加离散相模型(Discrete phase model,DPM)并进行雨滴和风场的同步迭代计算。在此基础上,系统研究了塔筒内外表面风驱雨量、雨滴附加作用力和雨致压力系数等影响规律,揭示了风雨场中塔筒表面速度流线、湍动能强度、雨滴运行速度和轨迹的作用机理。最终提出了基于风雨双向耦合算法的风-雨致等效压力系数新模型及其分布特性。研究结论可为此类冷却塔在极端气候下的表面荷载取值提供参考。The current wind resistance design methods for cooling towers ignore the effects of rainfall.But under extreme weather conditions with strong wind along with rainstorm,the rainstorm affects aerodynamic force on internal and external surfaces directly,and change turbulent effect of fluctuating wind.However,most traditional researches pay attention to shock effect on structure surface from wind driven rain.To solve this problem,aiming at a domestic large cooling tower which had built of the world's tallest(220 m),the wind-rain two-way bidirectional coupling algorithm is as the core.Firstly,the wind field around the cooling tower is simulated based on computational fluid dynamics(CFD)method,and the pressure distribution of cooling tower is compared with national standard and existing testing curve to verify the effectiveness of the numerical simulation.And the discrete phase model(DPM)is added and the iterative computation of raindrops and wind fields is carried out.Secondly,the influence laws on wind-driven rainfall,raindrop additional force and windinduced pressure coefficient on internal and external surface of tower drum are studied systematically,and the action mechanism of wind speed streamline,turbulence intensity and rain drops moving speed and trajectory on tower drum surface are revealed.Finally,the new model and distribution characteristics of wind-rain equivalent pressure coefficient are presented based on the wind⁃rain two-way bidirectional coupling algorithm.The conclusions can provide the reference for surface load value of such cooling towers.

关 键 词：大型冷却塔 风雨耦合 流场特性 气动力分布 

分 类 号：TU279.741[建筑科学—建筑设计及理论]