Aerodynamic control of Long span Bridges

该研究项目将对柔性桥面模型的稳定性和冲击响应进行CFD和风洞试验。桥面将安装振动襟翼型气动控制面。甲板上的传感器、数字控制系统和襟翼的电动驱动组合将用于增加桥梁在重扭模式下的稳定性。准三维CFD将首先用于计算颤振边界。从不同亚临界风速下的响应来评估颤振发生的临界风速。系统对指示控制面运动的反应也将被计算，结果将用于桥梁模型，首先在甲板的一部分上，然后在整个桥梁的三维模型上。将对一系列桥梁参数进行测量，包括甲板几何形状和平滑/湍流入射风，以评估该系统在提高临界颤振速度、减轻全尺寸悬索桥和斜拉桥的抖振和涡激振动方面的有效性。这些试验也将用于验证数值结果。

The research program will carry out CFD and wind tunnel tests of the stability and buffet response of flexibly-mounted bridge deck models. The bridge decks will be fitted with aerodynamic control surfaces of the oscillating flap type. A combination of sensors on the deck, a digital control system and electrical actuation of the flaps will be used to increase the bridge stability in the heave-torsion mode. Quasi-three-dimensional CFD will be used first to compute flutter boundaries. The critical wind speed for flutter onset will be evaluated from the responses at different subcritical wind speeds. The system response to indicial control-surface movement will also be computed and the results used to model bridges, first on a section of the deck and later on a three-dimensional model of a full bridge. Measurements will be made, for a range of bridge parameters including deck geometry and smooth/turbulent incident winds, to assess the effectiveness of the system in increasing critical flutter speeds and alleviating buffeting and vortex-induced-vibration for full scale suspension and cable-stayed bridges. These tests will also be used to validate the numerical results.