發(fā)布時(shí)間：2024-05-11 03:33

　　當(dāng)空氣或水等流體流經(jīng)鈍體型結(jié)構(gòu)達(dá)到一定條件會(huì)產(chǎn)生渦激振動(dòng)現(xiàn)象。對這種流體誘發(fā)振動(dòng)進(jìn)行探索在許多工程領(lǐng)域中都有很重要的研究價(jià)值。一方面用來評估鈍體結(jié)構(gòu)如橋梁,近海平臺及高層建筑群等等的穩(wěn)定性;另一方面通過振動(dòng)裝置用于流體能量的收集與轉(zhuǎn)化。目前已有大量文獻(xiàn)講述單柱結(jié)構(gòu)體繞流的探究,相比之下雙方柱繞流及其流體誘發(fā)振動(dòng)的研究需要更多關(guān)注。本文的模型是基于低雷諾數(shù)條件下,雙方柱串聯(lián)排列,下游方柱固定而上游方柱彈性固定。本文通過數(shù)值模擬研究在雷諾數(shù)Re=100和200情況下的上游方柱振動(dòng)響應(yīng)情況以及產(chǎn)生的機(jī)理。上游方柱只能橫向振動(dòng)。研究結(jié)果與單自由度單方柱振動(dòng)響應(yīng)作對比。兩個(gè)方柱中心距離為間隔比L*取2,6。通過改變固有頻率fn來控制無量綱速度Ur(Ur=1-30)的變化。本文通過固定雷諾數(shù)Re和間距比L*從如下方面分析上游方柱一維振動(dòng)響應(yīng),振動(dòng)幅值A(chǔ)*,振動(dòng)頻率fy,升力系數(shù)CL、升力和位移之間的相位差φ,斯特勞哈爾數(shù)St,方柱振動(dòng)流場渦旋結(jié)構(gòu)分布以及壓力分布。在Re=100且L*=2的條件下,為了更好的研究上游方柱振動(dòng)響應(yīng)隨Ur的變化情況,Ur=40的情況也會(huì)被模擬。另外,本文在Re=100,...

【文章頁數(shù)】：71 頁

【學(xué)位級別】：碩士

【文章目錄】：
摘要
Abstract
Acknowledgements
Nomenclature
Chapter 1 Introduction
    1.1 Background
    1.2 Research status of the subject and analysis
        1.2.1 Research on the single square cylinder
        1.2.2 The vibration of the cylinder in tandem arrangement
    1.3 Objectives and main contents
    1.4 Thesis outline
Chapter 2 Numerical method
    2.1 Governing equations
    2.2 Flow configuration and mesh distribution
    2.3 Boundary condition
    2.4 Study parameters
    2.5 Mesh method
    2.6 Numerical verification
        2.6.1 Mesh independence
        2.6.2 Meshing validation and results
    2.7 Summary
Chapter 3 Spacing ratio and Reynolds number
    3.1 The wake cylinder in reattachment regime (Re=100)
        3.1.1 The responses of amplitude and frequency ratio (m~*=3,ζ=0)
        3.1.2 Time history (lift and displacement) and wake structure (m~*=3,ζ=0,L~*=2)
    3.2 The wake cylinder in reattachment regime (Re=200)
        3.2.1 Transverse response and frequency ratio (m~*=3,ζ=0,L~*=2)
        3.2.2 Time history (lift and displacement) and wake structure (m~*=3,ζ=0,L~*=2)
    3.3 The wake cylinder in co-shedding regime (Re=100 and 200)
        3.3.1 Transverse response and frequency ratio (m~*=3,ζ=0,L~*=6)
        3.3.2 Time history (lift and displacement) and wake structure (m~*=3,ζ=0,L~*=6)
    3.4 Summary
Chapter 4 Mass and damping ratio
    4.1 The effect of mass ratio
        4.1.1 Vibration amplitude response
        4.1.2 Vibration frequency response
    4.2 The effect of damping ratio
        4.2.1 Vibration amplitude and frequency responses
    4.3 The effect of mass-damping ratio
        4.3.1 Vibration amplitude and frequency responses
    4.4 Summary
Conclusions
References
中文摘要



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