橋墩沖刷毀壞是橋梁失事的重要原因,橋墩沖刷深度估算是保障橋梁安全運行的重要保障,準(zhǔn)確估算橋墩附近沖刷形態(tài)及沖刷深度對于橋梁安全運行具有重要意義。論文基于FLOW-3D軟件,采用RNG6)-模型和大渦模擬(LES)模型,結(jié)合Meyer-Peter和Van Rijn的推移質(zhì)輸沙率公式,對單柱橋墩和雙柱橋墩附近的繞流流態(tài)及沖刷過程進(jìn)行了三維數(shù)值模擬,并與Melville試驗結(jié)果進(jìn)行了分析對比,主要研究內(nèi)容及結(jié)果如下:(1)從單柱橋墩最大局部沖刷坑深度模擬結(jié)果來看,分別采用RNG6)-模型和大渦模擬(LES)模型對橋墩沖刷情況進(jìn)行了模擬計算。結(jié)果表明,RNG k-ε模型計算出的最大沖深與Melville的實驗結(jié)果相差23.5%,LES大渦模擬計算值與Melville的實驗結(jié)果相差15.4%,顯然,LES大渦模擬計算結(jié)果比RNG k-ε模型的計算結(jié)果更加貼合實際情況。(2)選用LES大渦模擬,對Meyer-Peter公式、van Rijn公式的適用性進(jìn)行了評價。由Meyer-Peter公式計算出的沖坑形態(tài)、范圍、沖刷時間及最大沖坑深度與Melville實驗結(jié)果的吻合程度均較好;由van Rijn...

【文章頁數(shù)】：71 頁

【學(xué)位級別】：碩士

【文章目錄】：
摘要
ABSTRACT
CHAPTER 1 INTRODUCTION
    1.1 Background
    1.2 Literature Review
        1.2.1 The local scour at bridge pier
    1.3 Objectives, Subjects, and Significance
        1.3.1 Research objectives
        1.3.2 Research significance
        1.3.3 Limitations and scope of research
    1.4 Organization of Final Year Thesis
CHAPTER 2 MATERIALS AND METHODS
    2.1 Numerical Model
        2.1.1 Introduction of CFD
        2.1.2 Turbulence Models
    2.2 Sediment scour model
    2.3 Case study
CHAPTER 3 RESULTS AND DISCUSSION
    3.1 Single Column
        3.1.1 The application of Meyer-Peter Bedload transport equation
        3.1.2 The Application of van Rijn Bedload Transport Equations
        3.1.3 Influence of Flow Velocity
    3.2 Double column
        3.2.1 Flow Field Verification
        3.2.2 Verification of Scour Depth Prediction
        3.2.3 Scour Shape Verification
        3.2.4 Influence of pier-shape
    3.3 Summary
CHAPTER 4 CONCLUSIONS AND RECOMMENDATIONS
    4.1 Conclusion
    4.2 Outlook and Recommendations
REFERENCES
APPENDICES
ACKNOWLEDGEMENTS
AUTHOR BIOGRAPHY



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