关于二维平面圆柱涡激振动的数值模拟

Numerical Simulation on Vortex-induced Vibration of 2D-cylinder

利用有限元软件Adina建立平面二维圆柱绕流的数值模型,模拟低雷诺数条件下流体与圆柱间的涡激振动。随着流速加大,圆柱振动经历非锁定—锁定—脱离锁定的过程,由于锁定形态下圆柱振动与尾涡脱落引起的流体力形成共振,使圆柱的振幅增大。仅考虑圆柱顺流向振动时,横流向振幅略有增加;同时考虑圆柱在平面内的旋转和顺流向振动时,横流向振幅显著增加、锁定区间加宽,且质量比越低变化就越明显。

2D flow-around-cylinder numerical model is built to simulate the vortex-induced vibration of fluid body and cylinder with low Reynolds number by applying the finite element software Adina. The cylinder＇ s vibration response sequence characterized by non-locking state, lock-in state and unlock state is caused by acceleration of flow. In the lock-in state, the cylinder experiences large vibration amplitudes due to the resonance between cylinder vibration and fluid dynamic force caused by vortex shedding. Cross-flow response amplitude increases slightly in the case of stream-wise vibration. However, a significant increment is observed in the cross-flow response amplitude when the cylinder undergoes the stream-wise vibration and the in-plane rotation simultaneously. Meanwhile, the lock-in range expands as well. These trends become even more evident with decreasing mass ratio.