分离盘控制圆柱涡激振动的数值模拟研究

圆柱涡激振动问题一直以来备受关注,分离盘作为涡激振动抑制装置得到广泛研究。分离盘长度L与圆柱直径D之比L/D是影响抑制效果的主要因素。运用有限体积法结合RANS方程与一定的湍流模式离散和求解流场,通过编写自定义程序,使用动网格模拟结构物的运动带来的流域边界的变化,针对弹性支撑的圆柱及附加长度为0.5 D的分离盘模型,在约化速度Ur为2.5~13的情况下,对涡激振动及其抑制进行研究。结果表明:分离盘可以抑制甚至消除圆柱涡激振动,99%以上的振幅被抑制;锁定区始点被推后,锁定区变窄;附加分离盘的圆柱阻力和升力被抑制;其斯特鲁哈数(St)稍高于单圆柱St但差别不大。

Study on the Numerical Simulation of Cylinder Vortex-Induced Vibration Controlled by Separating Plate

The problem of cylinder vortex-induced vibration has been arousing major concern, and the separating plate has been extensively studied as an apparatus to restrain vortex-induced vibration. The ratio of the length of separating plate L to the diameter of the cylinder D, L/D, is the main factor to influence the effect of restriction. This paper applies the finite volume method, combined with the RANS equation and a certain turbulence mode, to disperse and solve the flow field. Through compiling the user-defined program and using dynamic mesh, it is feasible to simulate the change of basin boundary brought about by the motion of structures. Aimed at the flexibly supported cylinder and the separating plate model with an additional length of 0.5 D, vortex-induced vibration and its restriction are studied under the reduced velocity Ur of 2.5 to 13. The results show that the separating plate can restrain, even eliminate cylinder vortex-induced vibration, with over 99% of amplitude of vibration restricted. After the initial point has been pushed back, the lock room narrows down. Besides, the cylinder resistance and elevating force of the auxiliary separating plate are curbed, with its St slightly higher than that of a single cylinder, but without large difference.