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针对结构涡激振动数值模拟问题,以开源流体动力学计算软件OpenFOAM 3.0为平台建立结构涡激振动数值模拟方法,即将结构涡激振动问题简化为单自由度振子模型,采用Newmark-β法进行结构振动方程求解,应用OpenFOAM动网格求解器进行动网格计算与更新。以宽高比为5的矩形断面为例,首先采用3种不同的雷诺平均(RANS)湍流模型(即SST k-ω,k-ε和k-ω模型)进行风攻角为a=0°,2°,4°,6°时静止绕流计算,以检验不同湍流模型的计算精度;然后对矩形断面在0°风攻角下竖向涡振响应进行了数值模拟,并与已有文献和试验结果进行比较。研究表明:3种湍流模型的计算结果总体较为接近,且与试验结果较为吻合,其中SST k-ω湍流模型的计算结果与试验结果吻合相对最好;对于升力系数和升力矩系数,3种湍流模型的计算结果都与试验结果存在一定的差异;总体而言采用OpenFOAM的SST k-ω湍流模型所得静止矩形断面绕流计算结果与试验结果吻合较好。矩形断面涡激振动响应数值模拟结果与试验结果相比锁定风速区间有一定前移,且最大涡振振幅较试验结果略偏大。
Aiming at the problem of vortex-induced vibration numerical simulation of structures, the open-source fluid dynamics calculation software OpenFOAM 3.0 was used to establish the numerical simulation method of vortex-induced vibration. The vortex-induced vibration was simplified to a single-degree-of-freedom oscillator model. The Newmark- The vibration equation is solved and the dynamic grid computing and updating are implemented by using OpenFOAM moving grid solver. Taking a rectangular section with an aspect ratio of 5 as an example, three different RANS turbulence models (ie, SST k-ω, k-ε and k-ω models) , 2 °, 4 ° and 6 °, respectively, to test the calculation accuracy of different turbulence model. Then the vertical vortex-induced response of rectangular section under 0 ° angle of wind attack is numerically simulated and compared with the existing literature Compare with test result. The results show that the calculated results of the three turbulence models are generally close and agree well with the experimental results. The calculated results of the SST k-ω turbulence model are in good agreement with the experimental results. For the lift coefficient and the torque coefficient, three turbulence models The calculated results of the model are all different from the experimental results. In general, the calculated results of the flow around the rectangular section with static SST k-ω model obtained by OpenFOAM agree well with the experimental results. Compared with the experimental results, the results of the simulation of the vortex-induced vibration of the rectangular section have a certain forward movement, and the amplitude of the maximum vortex vibration is slightly larger than the experimental results.