邻近较小直径圆柱的圆柱流致振动特征研究

发布时间：2023-03-19 21:39

　　在工程应用中,流致振动(FIV)现象普遍存在,例如核反应堆中的石墨棒,电站的冷却塔,换热器的换热管排等,如果在相关的结构设计过程中忽略了流致振动的影响,就可能导致工程设备的损坏,给工业生产带来巨大损失。为便于研究FIV的机理,本文以双圆柱模型为的研究对象,两圆柱直径比为0.4,较小直径的圆柱固定无振动,较大直径的圆柱只在垂直于来流方向进行自由振动。通过改变两圆柱相对角度θ以及两圆柱之间的间隙比L/d(L为两圆柱中心距离减去大圆柱半径,d为小圆柱直径)可以得出不同排列情况下的流致振动特点。本文主要测量来流速度介于1.8 m/s至20 m/s之间时大直径圆柱的振动情况,主要有以下四种:无振动(0),共振(SV),弛振(G),小振幅振动(SV)。根据振动情况的不同把整个研究区域进行划分,然后在每个区域选取几个具有代表性的点,测量其大直径圆柱表面的压力分布以及两圆柱之间和尾流的涡结构。将振动情况,压力分布和涡结构三者联系起来即可较完整的描绘各个振动情况的产生机理。随着θ和L/d的变化,大直径圆柱表现出不同的振动情况,据此可以将整个研究区域分为五个部分,即小圆柱位于上游的共振和弛振区(I区),小...

【文章页数】：78 页

【学位级别】：硕士

【文章目录】：
摘要
ABSTRACT
ACKNOWLEDGEMENTS
NOMENCLATURE
CHAPTER 1 INTRODUCTION
    1.1 Background
    1.2 Literature review
        1.2.1 Tandem configuration
        1.2.2 Side-by-side configuration
        1.2.3 Staggered configuration
        1.2.4 Excitation and suppression of vibrations
        1.2.5 Present direction
    1.3 Objectives
    1.4 Thesis outline
CHAPTER 2 EXPERIMENTAL SET-UP AND TECHNIQUES
    2.1 Wind tunnel
    2.2 Experimental details
    2.3 Measurement of vibration response
    2.4 Pressure measurement
    2.5 PIV measurement
CHAPTER 3 RESULTS AND DISCUSSION
    3.1 Vibration Response
        3.1.1 Structural properties
        3.1.2 Vibration response of the large cylinder
    3.2 Pressure distribution
        3.2.1 Pressure validation
        3.2.2 Pressure distribution in Regime I
        3.2.3 Pressure distribution in Regime II
        3.2.4 Pressure distribution in Regime III
        3.2.5 Pressure distribution in Regime IV
        3.2.6 Pressure distribution in Regime V
    3.3 PIV measurement
        3.3.1 Regime I
        3.3.2 Regime II
        3.3.3 Regime III
        3.3.4 Regime IV
        3.3.5 Regime V
    3.4 Summary
CONCLUSIONS
REFERENCES



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