Abstract This paper investigated the Hopf bifurcation and post-instability of tube bundles subjected to two-phase cross-flow and loose support. A nonlinear dynamic model of a single tube in tube bundles considering the effects of two-phase flow force and impact force between the tube and tube support plate was established. Based on this model, a numerical simulation program was written to calculate the bifurcation diagrams, limit cycle motions, and quasi-periodic motions of the tube. The numerical results showed that a supercritical Hopf bifurcation of a single flexible tube in a tube array at the original stable equilibrium occurs at the Hopf bifurcation velocity within void fraction ranging from 0% to 80%. And, the vibrations of the tube for the high void fraction condition are much more complex than those for the low void fraction which could be the reason for the early damage of the tube bundles in a steam generator.

中文翻译：

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两相错流松支撑管束Hopf分岔及后失稳数值研究

摘要 本文研究了管束在两相错流和松散支撑作用下的Hopf分岔和后失稳。建立了考虑管与管支撑板之间两相流力和冲击力影响的管束中单管非线性动力学模型。在此模型的基础上，编写了数值模拟程序，计算了管子的分岔图、极限循环运动和准周期运动。数值结果表明，在初始稳定平衡的管阵列中单个柔性管的超临界 Hopf 分叉发生在 Hopf 分叉速度在 0% 到 80% 的空隙率范围内。和，