錦屏一級大壩是中國最大的水電站項目之一。由于高水頭和大泄流量,有發(fā)生空蝕破壞的風險。本文使用CFD數(shù)值模擬研究,泄洪洞采用摻氣坎進行摻氣減蝕時,水流的水力特性。論文的主要研究內容和成果如下:1.建立泄洪洞和摻氣坎整體模型,為數(shù)值模擬計算做準備,以評估氣蝕破壞發(fā)生的可能性。摻氣坎作為預防氣蝕破壞的一種措施,是最便宜和最有效的解決方案。泄洪洞中設置有4處摻氣坎,全部采用挑坎+跌坎組合型摻氣坎,與錦屏實際工程中采用的摻氣坎類型一致。2.數(shù)值模擬使用FLUENT求解平均Reynolds-averages Navier–Stokes方程。湍流模型選擇可實現(xiàn)的k-ε模型,以及應用VOF法計算水氣兩相流和水氣交界面的追蹤。針對3種庫水位和2種閘門開度,共6種情況,分別為:1880m,1865m和1850m的庫水位,以及閘門全開和閘門半開,進行了非穩(wěn)態(tài)數(shù)值計算。獲得了6種情況下水流的自由面、速度、壓強和摻氣長度等的數(shù)值模擬數(shù)據(jù)。3.數(shù)值模擬的數(shù)據(jù)與1:30模型實驗的數(shù)據(jù)進行對比驗證。在庫水位1880m和閘門全開時,4個坎前平均速度的平均誤差為3.1%、33個底板壓強測點的平均誤差為6.16%、31個自... 

【文章來源】：華北電力大學(北京)北京市 211工程院校 教育部直屬院校

【文章頁數(shù)】：79 頁

【學位級別】：碩士

【文章目錄】：
摘要
Abstract
Acknowledgement
Nomenclature
Chapter 1. Introduction
    1.1. General Description
    1.2. Research Objectives
    1.3. Methodology
    1.4. Thesis Outline
Chapter 2. Theoretical Background
    2.1. Cavitation and its Mechanism
    2.2. Cavitation Parameters
    2.3. Prevention of Cavitation Damage
        2.3.1. Cavitation Prevention
        2.3.2. Controlled Cavity Collapse
        2.3.3. Use of Cavitation-Resistant Materials
        2.3.4. Aeration
    2.4. Concept of Aeration
        2.4.1. Aeration Methods and Mechanisms
        2.4.2. Aerator Location and Spacing
        2.4.3. Estimation of Air Entrainment Capacity
    2.5. Computational Fluid Dynamics
        2.5.1. Governing Equations for CFD
        2.5.2. Pre-Processing
        2.5.3. Solver
    2.6. VOF Model
        2.6.1. The Implicit Scheme
        2.6.2. Limitations
Chapter 3. Various Methods and Stages Used in CFD Modelling of Jinping-I Hydro Project
    3.1. Pre-Processing Stage
    3.2. Solver Stage
    3.3. Post-Processing Stage
        3.3.1. Static Pressure Distribution
        3.3.2. Velocity
        3.3.3. Water surface
Chapter 4. Simulation Results of CFD Modelling of Jinping-I Hydro Project and its Discussion
    4.1. Simulation Results of CFD Modelling of Jinping-I Hydro Project
        4.1.1. Calculation of Velocity and Cavitation Number for Full and Half Conditions at Different WaterLevels
        4.1.2. Calculation of Water Surface Profile for Full and Half Conditions at Different Water Levels
        4.1.3. Calculation of Pressure Distribution for Full and Half Conditions at Different Water Levels
        4.1.4. Calculation of Aeration Cavity Length for Full and Half Conditions at Different Water Levels
    4.2. Discussion and Accuracy Regarding Verification, Convergence and Uncertainty
        4.2.1. Verification of the Model
        4.2.2. Convergence
        4.2.3. Uncertainty and Error in CFD simulations
    4.3. Summary
Chapter 5. Conclusions and Future Works
    5.1. Conclusions
    5.2. Future works
References


【參考文獻】：
期刊論文
[1]HYDRAULIC CHARACTERISTICS OF PLUG ENERGY DISSIPATER IN FLOOD DISCHARGE TUNNEL[J]. TIAN Zhong , XU Wei-Lin, WANG Wei, LIU Shan-Jun State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China,.  Journal of Hydrodynamics. 2009(06)
[2]通氣減蝕挑坎水力學問題的試驗研究[J]. 時啟燧,潘水波,邵媖媖,袁小勇.  水利學報. 1983(03)



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