大跨度桥梁箱梁风速全过程的被动自吸/吹气流动控制研究

According to the wind-induced dynamic effects of the box-type decks of the long-span bridges, this project will investigate a passive self-suction/jet flow control on the wind effects in the full speed process of the box-type girders of the long-pan bridges. First, this project will study on the effectiveness of the self-suction/jet flow control to the static aerodynamic forces and the flow fields around the box-type girders, and determine the parameter configuration method. Next, this project will investigate the self-suction/jet flow control on the vortex-induced vibrations of the box-type girder; and analyze the influence of the control to the vibration amplitude, lock-in range, the vortex shedding pattern, separation location and the stability of the flow field. Then, this project will investigate the influence of the self-suction/jet flow control to the aerodynamic damping ratio, the flutter type and the flutter critical speed in the flutter instability process of the box-type girder, and analyze the variation of the vortex shedding intensity, the detached vorticity size and the separation location in the control parameters. At last, this project will set up a unified design method of the self-suction/jet flow control for the full speed process of the box-type girders of the long-pan bridges, combining the control effectiveness of above three cases and considering the characteristics of the bridge aero-elastic deformations. The project study will enrich and develop the wind engineering theory of super long-span bridges and provide the scientific and technical supports to protect performance and the service safety of long-span bridges and have important scientific significance and practical value.

针对大跨度桥梁箱型主梁的风致动力效应，研究自吸/吹气流动控制对箱梁风速全过程绕流场的控制机理与设计方法。首先，研究自吸/吹气流动控制对大跨度桥梁箱梁静力气动力及绕流场的控制效果及参数设置方法。然后，研究大跨度桥梁箱梁涡激振动的自吸/吹气流动控制，分析其对箱梁涡激振动幅值、锁定区及绕流场的旋涡脱落模式、分离点位置、压力分布及流动稳定性的影响规律。进一步，研究自吸/吹气流动控制对大跨度桥梁箱梁颤振失稳过程的气动阻尼、颤振形态、颤振临界风速等的影响规律，分析箱梁旋涡脱落强度、分离涡尺寸以及分离点位置随控制参数的变化规律。最后，综合三个工况的控制规律，考虑桥梁气弹变形特点，建立大跨度桥梁箱梁风速全过程自吸/吹气流动控制的统一设计方法。本项目的研究将丰富和发展特大跨度桥梁结构风工程理论，为保障大跨度桥梁服役性能和服役安全提供科学和技术支撑，具有重要的科学意义和实用价值。

针对大跨度桥梁箱型主梁的风致动力效应，研究自吸/吹气流动控制对箱梁风速全过程绕流场的控制机理与设计方法。首先，通过对自吸/吹气孔开孔区域、展向间距及雷诺数变化对箱梁静力气动力及绕流场的控制效果进行研究，同时对桥梁两侧设置襟翼研究进行桥梁静力风荷载控制效果验证。然后，研究桥梁表面不同开孔区域对大跨度桥梁箱梁涡激振动的自吸/吹气流动控制，分析其对箱梁涡激振动幅值、锁定区、尾流涡能量谱密度、绕流场的旋涡脱落模式、分离涡生成位置及展向流场变化规律。此外，研究桥梁表面不同开孔区域对大跨度桥梁箱梁颤振失稳的颤振临界风速的影响。最后，综合三个方面的的控制开孔规律，考虑实际桥梁气弹变形特点，通过对大跨度桥梁拉条模型涡激振动控制效果及被动吹/吸气流动控制统一设计方法。本项目的研究将丰富和发展特大跨度桥梁结构风工程理论，为保障大跨度桥梁服役性能和服役安全提供科学和技术支撑，具有重要的科学意义和实用价值。