低雷诺数下圆柱涡激振动的二维有限元数值模拟

Two-dimensional FEM model of Vortex-Induced Vibration of a Circular Cylinder

采用有限元方法求解原始变量的二维不可压粘性流体的N-S方程,计算了雷诺数从90到150范围内圆柱绕流引起的涡激振动,完整地再现了流固耦合系统从不共振到频率锁定,再到脱离锁定的过程,成功地预测到了涡激振动的“拍”和“锁定”现象,并与A nagnostopou los和B earam an的试验结果进行了比较。计算涡激振动时用ALE方法分析圆柱和流体的耦合作用,圆柱振动被简化为质量-弹簧-阻尼系统。

The finite element method was employed to solve the N-S equation. Incorporated with the vibration equation, the vortex-induced vibration of the circular cylinder is studied by an Arbitrary-Lagrangian-Eulerian （ALE） algorithm. The Reynolds number based on the cylinder diameter and the undisturbed flow velocity range from 90 to 150. The motion of the cylinder was modeled by a spring-damper-mass system. The numerical model has been validated by comparison with the experimental data in literature. The ＂lock-in＂ and ＂beating＂ phenomena were successfully reproduced in the numerical test.