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近年来,计算流体动力学(CFD)在桥梁风工程中得到了越来越多的尝试与应用。CFD的应用不仅仅是顺应了计算机硬件浮点运算速度的快速发展,而且在处理复杂问题、时间及经济成本方面与风洞试验相比具有巨大的优越性。但是,这一优越性是建立在CFD求解结果具有实用精度的假设前提下的。该文综述了桥梁气动力CFD数值模拟中湍流问题的起源、各类湍流模型的本质特征及其适用范围与局限性。在此基础上,广泛调研了CFD在国内外桥梁气动力数值模拟中的应用,分别按静气动力与气弹两大类问题统计分析了目前CFD模拟与风洞试验结果之间的差距。结果表明,对于静气动力问题,CFD模拟的误差普遍在10%~40%之间;对于气弹问题,CFD模拟的误差普遍介于20%~300%。这一现实表明,以目前的水平,CFD尚无法独立于风洞试验而对桥梁气弹问题给出可靠的评估。要充分发挥计算流体动力学的优势,则必须结合湍流理论,加强各种湍流模型在各类桥梁气动问题中的应用基础研究。
In recent years, computational fluid dynamics (CFD) has been more and more tried and applied in bridge wind engineering. The application of CFD not only conforms to the rapid development of floating point computing speed of computer hardware, but also has great advantages compared with wind tunnel test in dealing with complicated problems, time and economic cost. However, this superiority is based on the assumption that the CFD results are of practical precision. This paper summarizes the origins of turbulence problems in numerical simulation of bridge aerodynamic CFD, the essential features of various types of turbulence models and their applicability and limitations. Based on this, the application of CFD in the numerical simulation of bridge aerodynamics at home and abroad has been extensively studied. The differences between current CFD simulation and wind tunnel test results are statistically analyzed according to the problems of static aerodynamics and gas bomb. The results show that the CFD simulation error is generally between 10% and 40% for the aerostatic problem and the CFD simulation error is generally between 20% and 300% for the gas bomb problem. This reality shows that, at its present level, CFDs can not give a reliable assessment of bridge gas bomb problems independently of wind tunnel tests. In order to give full play to the advantages of computational fluid dynamics, we must combine the theory of turbulence and strengthen the application of various turbulence models in various types of bridge aerodynamics.