非稳态流体力作用下两相流管束流弹失稳研究

流弹失稳会引起传热管振幅过大而发生磨损破坏，是两相流作用下蒸汽发生器管束流致振动的重要机理。为了较为准确地预测两相流作用下圆柱管的失稳临界流速，对试验测量的两相流非稳态流体力进行参数拟合，建立了气-水两相流作用下单管的动力学模型。通过无量纲化，运用Galerkin方法对方程变量进行离散后，联立求解方程得到了不同空泡份额的临界流速。数值结果表明，数值解与试验测得失稳临界流速较为吻合，验证了该模型可用于两相流传热管临界流速的预测。 

Fluidelastic Instability of Tube Bundles under Two-Phase Flow Subject to Unsteady Fluid Force

Fluidelastic instability causes the large amplitude of the heat transfer tube, which results in its wear out. It is the key mechanism of the fluid-induced vibration of the team generator tube bundles?subject to two-phase flow. In order to predict more accurately the critical?flow of instability,?the motion equation of single tube is firstly?established utilizing the unsteady?fluid force coefficients of two-phase flow?which obtained by fitting experimental result data.?After?the?nondimensionalize and Galerkin discretization of the analytical model,?the critical flow velocity of each void fraction is calculated by solving the system of equations. Numerical results show that the numerical critical fluid force of instability?agrees well with experimental results, which proving that the analytical model utilizing fitting parameters of unsteady fluid force of two-phase flow is available for the predicting of the critical velocity of instability.