传热管在内外流体及间隙作用下的非线性振动特性

Nonlinear Vibration Characteristics of Heat Transfer Tube Subjected to Internal and External Flows and Loose Support

考虑轴向伸长引起的几何非线性和间隙支撑非线性,利用尾流振子模型模拟了流体力的变化及传热管振动的耦合,基于力平衡法建立了传热管在内外流体和间隙支撑作用下的非线性运动方程,采用4阶Runge-Kutta算法计算了耦合系统的动力学响应,研究了传热管在内外流体和间隙支撑作用下的非线性响应特性,得到了不同内流速度下以外流速度为分叉参数的分叉图。结果表明,内流速度对有支撑间隙的传热管耦合系统的动力学特性有重要影响。

Based on force balance method,the nonlinear differential equation of heat transfer tube,subjected to internal and external flows together with loose support,was developed.The nonlinearity associated with the mean axial extension of the tube was accounted for in the current work.Meanwhile,the interaction of tube vibration and fluid force induced by cross flow were modeled by wake oscillator model.The response of the coupling system was calculated using a fourth order Runge-Kutta integration algorithm and the nonlinear dynamics characteristics were studied.The bifurcation diagrams for vibration amplitude with cross flow velocities were constructed.The results show that the internal flow velocity has remarkable effect on coupling system of heat transfer tube with loose support.