Vibration Response of a U-Tube Bundle with Anti-Vibration Bar Supports due to Turbulence and Fluidelastic Excitations
Vibration Response of a U-Tube Bundle with Anti-Vibration Bar Supports due to Turbulence and Fluidelastic Excitations
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DOI：
10.1006/jfls.1995.1047
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发表时间：
1995-11
影响因子：
3.6
通讯作者：
K. Haslinger;D. Steininger
中科院分区：
文献类型：
--
作者：
K. Haslinger;D. Steininger
摘要 描述了一种流动测试程序，该程序表征带有防振杆 (AVB) 支撑的 5 x 12 U 形管束的湍流和流体弹性引起的管响应。管束在三种不同的管/AVB 支撑间隙条件下进行了测试。还使用各种精确设置的边界条件对单个孤立的管进行了研究。后面的这些测试提供了在流动湍流和流体弹性管激励条件下精确的管响应和管/管支撑相互作用数据。这些结果用于验证管振动和磨损的非线性有限元计算机代码模拟。传统的加速度计和接近探头仪器可识别模态管响应以及管束 U 形弯曲区域中的平面内和平面外管运动行为。用与管集成的力/运动测量装置代替短管部分，可以对收缩力/冲击力以及管与 AVB 接触时的管平面内滑动运动进行非侵入式监测。这种安排允许通过实验确定“工作率”和冲击力直方图。在一系列三项测试中，使用增加的支撑间隙条件，产生了复杂的管振动模式，表现出 AVB 运动的影响。受到流动影响的中心管首先响应湍流激励，然后，随着流动的增加，在基本振动模式下表现出可预测的流体弹性不稳定性。流量的进一步增加导致振幅控制的极限循环。这些循环显示响应频率逐渐增加，并有模式切换的证据。流体弹性响应的阈值速度随着 AVB 接触点的数量和预载水平的增加而增加。在低横流速度下，不同条件下的工作效率结果差异很大。在较高的错流速度下，即使存在不同的磨损机制（滑动与冲击），也获得了类似的工作速率数据。
Abstract A flow test program is described which characterizes turbulence and fluidelastically induced tube responses of a 5 by 12 U-tube bundle with Anti-Vibration Bar (AVB) supports. The tube bundle was tested with three different tube/AVB support-clearance conditions. Individual, isolated tubes were also investigated with various, precisely set boundary conditions. These latter tests provide accurate tube response and tube/tube support interaction data under conditions of flow turbulence and fluidelastical tube excitation. These results are used for verification of nonlinear finite element computer code simulations of tube vibration and wear. Conventional accelerometer and proximity probe instrumentation identified modal tube responses, and in-plane and out-of-plane tube motion behavior in the U-bend region of the tube bundle. Replacing short tube sections with force/motion measurement devices integral with the tube enabled nonintrusive monitoring of contract/impact forces, as well as of tube in-plane sliding motions when the tube was in contact with an AVB. This arrangement allowed for the experimental determination of "work rates" and impact force histograms. During a series of three tests, using increasing support clearance conditions, complex tube vibration patterns were produced that exhibited effects of AVB movement. Centered tubes, subjected to flow, first responded to turbulence excitation, and then, as flow increased, exhibited predictable fluidelastic instabilities at fundamental vibration modes. Further increase in flow resulted in amplitude controlled limit cycles. These cycles showed gradually increasing response frequencies with evidence of mode switching. The threshold velocity for fluidelastic response increases with the number of AVB contact points and the level of preload. At low cross-flow velocities, work rate results vary significantly for different conditions. At higher cross-flow velocities, similar work-rate data were obtained, even though different wear mechanisms (sliding versus impact) existed.