基于小型水平轴风力机扰流的大跨桥梁主梁涡激振动流动控制

With the increase of bridge span, wind-induced vibration is becoming the primary factor restricting the development of long-span bridges. Vortex-induced resonance is one of the serious issues which needs to be solved in the designing of long-span bridge. Small horizontal axis wind turbine not only can harvest wind energy but also can generate streamwise vortices in its wake; the streamwise vortices can suppress spanwise vortex shedding around a bridge-deck and then effectively mitigate vortex-induced vibration (VIV). The research project attempts to develop the flow control method which based on small horizontal axis wind turbine perturbation to mitigate VIV of long-span bridges. Theoretical analysis, numerical simulation and wind tunnel test are used to conduct the project research. Firstly, the integration system of bridge-deck section test model and wind turbine test model is developed. Secondly, wind tunnel test method of bridge-deck section model and wind turbine model is established; the relationships are investigated between control parameters and control effects on VIV; the effects of the small horizontal axis wind turbine on bridge-deck aerodynamic force as well as flutter stability are also studied. Thirdly, interaction mechanism between the wake vortex and flow field around the bridge-deck is studied from the aspect of periodic flow instability and vortex motion; the power-generation performance of the wind turbine is estimated; a comprehensive evaluation method of small horizontal axis wind turbine is established with good control effect, power generation efficiency and economy. Lastly, the integrated method of VIV control and wind power harvest for long-span bridge deck is developed. The project will provide a new perspective for solving wind-resisting problems with the development of long-span bridges. The expected research results will further enrich and develop wind-resisting theory of bridges.

随着桥梁跨度的不断增长，风致振动逐渐成为制约大跨桥梁进一步发展的主要因素。其中，涡振是大跨桥梁主梁设计中亟需解决的关键风振问题之一。本项目旨在利用风力机能够产生顺流向涡的特点，抑制主梁展向涡的脱落，达到高效抑制涡振的目的，最终发展具有风能收集功能的桥梁主梁涡振控制方法。本项目综合运用理论分析、数值模拟与风洞试验开展相关研究工作。首先，研发小型水平轴风力机与主梁节段模型一体化试验装置系统；然后，建立相关风洞试验方法，研究风力机控制参数对涡振控制效果的影响规律，并研究该控制措施对主梁气动力与颤振稳定性的影响；最后，分析风力机尾涡对主梁绕流场的影响机制，评估风力机发电性能，建立兼具良好涡振控制效果、发电效率以及较经济的风力机综合评价方法，发展大跨桥梁主梁涡振控制与风电集能一体化方法。本项目研究将为解决大跨桥梁发展所面临的抗风难题提供崭新的视角，预期成果将丰富和拓展大跨桥梁抗风理论。

近年来，随着桥梁跨度的不断增长，桥梁结构变柔，风致敏感性增强，桥梁涡振时有发生，严重威胁桥梁的寿命和行车安全，因此是大跨桥梁主梁设计中亟需解决的关键风振问题之一。本项目利用风力机能够产生顺流向涡的特点，抑制主梁展向涡的脱落，达到高效抑制涡振的目的，最终开发了具有风能收集功能的桥梁主梁涡振控制方法。本项目综合运用理论分析、数值模拟与风洞试验开展相关研究工作。首先，研发了小型水平轴风力机与主梁节段模型一体化试验装置系统，揭示了小型水平轴风力机试验模型所产生尾流顺流向涡结构特征；然后，根据风力机气动相似理论与桥梁气弹性相似理论建立了风力机与桥梁主梁节段模型一体化测振风洞试验方法，并提炼了出相关控制参数；采用风洞试验验证了小型水平轴风力机对主梁涡振的控制效果，掌握了关键控制参数对于涡振控制效果的影响规律；探明了该控制措施对主梁颤振稳定性的影响。然后，建立了小型水平轴风力机尾涡数学模型（致动盘模型），并采用数值模拟加以验证；针对涡振发生时箱梁主梁流场呈周期性（展向涡周期性脱落）的特点，探究了绕流场在风力机扰流下的周期稳定性，从流动稳定性角度验证了风力机扰流流动控制机理，揭示了顺流向涡结构与主梁绕流场展向涡结构之间的相互作用，探究了尾涡对主梁绕流场展向涡结构的抑制机制。最后，评估了风力机控制参数对风力机发电性能的影响以及风力机综合评价方法，给出了大跨桥梁主梁涡振控制与风电集能一体化方法初步设计方法。本项目研究将为解决大跨桥梁发展所面临的抗风难题提供崭新的视角，预期成果将丰富和拓展大跨桥梁抗风理论。