数值模拟桥梁断面气动导数和颤振临界风速

从描述流体绕运动的刚性断面流动的N S方程出发,首先采用时间二阶Projection 2算法对控制方程作分裂步处理,得到的求解方程空间离散采用有限体积法,物面运动方式为自由度解耦的强迫振动,采用计算网格和刚性截面刚性连接、同步运动的动网格技术,数值模拟了振动的大带东桥绕流场,由计算的气动力按最小二乘法提取气动导数,最后计算了大带东桥的颤振临界风速。计算的大带东桥气动导数与风洞试验有很好的一致性,大带东桥颤振临界风速模拟值与风洞试验结果偏差很小,证明了本文数值方法的正确性和工程适用性。

Numerical simulations for aerodynamic derivatives and critical flutter velocity of bridge deck

Flow field around 2D moving rigid cross-section was simulated by using moving grid technique and forced vibration procedure. The Projection-2 scheme was employed to decouple the governing N-S equations and finite volume method (FVM) was used to solve the obtained equations. The flutter derivatives were extracted from obtained aerodynamic forces with least square method. The computed aerodynamic derivatives of the Great Belt East Bridge were compared with results from section model tests in wind tunnel and good agreement was found. Also, small deviation is shown on critical flutter velocity of Great Belt East Bridge based on flutter derivatives obtained from the present study and from wind tunnel tests. The validity of present approaches and its applicability to engineering are proved.