台风作用下超高层建筑基于分离涡模拟的流固耦合风效应数值模拟研究

Super-tall buildings are usually slender, lightweight, and flexible and have low damping and natural frequencies, which must considerate the effect of Fluid-Structure interaction in design of wind-induced responses. This project focuses on accurate prediction of wind-induced aeroelastic effects of super-tall building with the moderate grid number and higher computational efficiency. In this study, the natural unsteady wind in the atmospheric boundary layer under typhoon and monsoon weather condition is modeled with a new artificial inflow turbulence generation method. Then, the turbulent flow is simulated by a Zonal Detached-Eddy Simulation, and two-way FSI simulation based on ANSYS Workbench software Platform is conducted to caculated the wind-induced aeroelastic vibration of the CAARC standard tall building and Taipei 101 Tower. The numerical simulation results are compared with those from wind tunnel tests and full-scale measurements to verify the accuracy, reliability of the FSI numerical method adopted in this project. The mechanism of the aeroelastic wind-induced vibration of high-rise buildings is investigated. The aeroelastic wind loads and wind-induced responses under typhoon and monsoon weather condition are presented and discussed. The effects of wind field under different climate conditions on the wind-induced aeroelastic responses of super-tall building are investigated. The approachs used in this reaserch is an effective tool for structural engineers to improve the wind resistance design method and the occupant comfort evaluation of high-rise building structure consideration aeroelastic effects.

超高层建筑质量轻，柔度大、频率及阻尼低，其结构与流场之间的耦合作用是研究其风振响应时不可忽略的因素。本项目以兼顾网格、精度和计算效率的需求，准确地预测超高层建筑流固耦合风效应为目标。以CAARC标准建筑及台北101大厦为研究对象，采用ZDES分离涡模拟方法及新的更能反映实际大气边界层风场的CFD入口湍流风场生成方法，基于ANSYS的Workbench平台实现超高层建筑季风及台风作用下流固耦合风效应的数值模拟。通过将数值模拟结果与风洞试验及现场实测结果进行对比，验证本项目流固耦合数值方法的准确性、可靠性。探讨超高层建筑风致耦合振动机理。分析季风及台风风场气候条件下超高层建筑流固耦合风荷载、风振响应的特点，研究不同风场气候模式对超高层建筑风致耦合振动响应的影响。本项目研究可为实际工程中超高层建筑居住者舒适性和考虑流固耦合效应的超高层建筑结构抗风设计的完善提供重要依据。

结构流体间的耦合作用是研究风敏感结构振动特性不能忽略的一个因素。因此研究超高层建筑结构的风致振动特性时，考虑结构流场之间的耦合作用是必要的。对超高层建筑流固耦合风效应研究主要包括现场实测、风洞试验和数值模拟三种方法。数值模拟与其他两种方法相比，其优越性在于效率高、费用省；可以提供更多的流场信息；便于进行参数分析，机理研究，具有模拟真实风环境的能力。分离涡模拟（DES）相对于大涡模拟（LES）具有网格量和计算代价的优势，以及与大涡模拟方法相当的计算精度。本项目以CAARC标准建筑、台北101大厦以及深圳平安大厦为研究对象，采用分离涡模拟方法及新的更能反映实际大气边界层风场的CFD入口湍流风场生成方法对建筑周围流场进行模拟。基于ANSYS的Workbench平台实现风场建筑双向流固耦合振动的数值模拟。将数值模拟结果与风洞试验及现场实测结果进行了对比，结果表明本项目采用的DSRFG湍流生成法及分离涡模型的流固耦合数值模拟具有较高的准确性与可信度。分析了考虑和未考虑流固耦合作用下超高层建筑表面风压分布、风荷载特性、流场涡旋脱落模式及结构的顺、横风向位移响应的变化规律；分析了不同湍流来流条件对超高层建筑风致响应的影响以及流固耦合效应对结构气动力特性的影响；探讨了超高层建筑风致耦合振动机理。本项目研究成果将为实际工程中超高层建筑的居住者舒适性和考虑流固耦合效应的超高层建筑结构抗风设计提供理论依据。