两相横流作用下的旋转三角形管束流弹失稳研究

Fluidelastic Instability of Rotated Triangle Tube Bundles Subject to Two-Phase Cross-Flow

为了较为准确的预测两相流作用下圆柱管的失稳临界流速,采用试验测量的两相流准稳态流体力系数,对单向流的准稳态模型进行扩展,建立了气-水两相流作用下的旋转三角形管束中间悬臂自由管的动力学模型,运用Galerkin方法对方程变量进行离散后,求解特征方程得到了不同空泡份额的临界流速,并运用龙格-库塔法求解动力学方程得到位移时程响应。数值结果表明,临界流速随着空泡份额的增大而增大,且所建模型计算结果与试验测量值较为吻合。因此,本研究所建模型可用于两相横流作用下的旋转三角形管束流弹失稳临界流速预测。

In order to predict more accurately the critical flow of fluidelastic instability, the motion equation of a cantilevered tube is established utilizing quasi-static fluid force coefficients of two-phase flow. After Galerkin discretization of the analytical model, the critical flow velocity of each void fraction is obtained by solving the characteristic equations. Moreover the response of cantilevered tube is solved using Runge-Kutta algorithm. Numerical results show that the critical velocity of instability increases with the increasing of the void fraction, and the numerical results agree with experimental results, which proving the analytical model utilizing quasi-static fluid force coefficients of two-phase flow is available for predicting the critical velocity of fluidelastic instability.