卡艾瑋臺灣大學：土木工程學研究所潘彥同PAN, Yen-TungYen-TungPAN2007-11-252018-07-092007-11-252018-07-092006http://ntur.lib.ntu.edu.tw//handle/246246/50203本論文之研究目標為瞭解由許多小氣泡所形成的異重流與液體的交互作用。氣泡流在斜版上運動還有所堆積起來像啤酒泡沫的運動是這實驗中想要知道的，這實驗在現象上就像有一個異重流流進一個水庫或是湖泊，然後我們把他倒過來看，我們利用粒子影像的方法來做到氣泡的流場分析，並且能得到結果，之後理論用淺水波的的假設來推導出氣泡流跟形成泡沫之前的方程式，最後我們可以去有限體積法來做計算，並且把得到的結果跟之前的實驗作比較。The present investigation focuses on bubble currents moving along a rigid ceiling, then impacting onto a floating foam raft. This flow constitute an inverted analogue of the density currents encountered in lakes and reservoirs. Both experiments and computations are performed. In the experiments, Particle Tracking Velocimetry (PTV) is used to capture the flow field both for the fast currents and for the slow foam raft. For the computations, a new set of governing equations based on the shallow flow assumption are derived. A special feature of the equations is that they include different terms for the ceiling current and for the foam raft. The Finite Volume Method (FVM) is used to solve the equations numerically. Finally the results of the numerical computations are compared with the experimental measurements.Chapter 1 Introduction 1.1 Chapter 2 Experimental set-up and parameters 2.1 2.1 Experimental set-up 2.2 2.2 Liquid properties 2.6 2.2.1 Density 2.6 2.2.2 Viscosity 2.7 2.2.3 Surface Tension 2.8 2.2.4 Synthesis of results 2.9 2.3 Bubble properties 2.11 Chapter 3 Imaging analysis and results 3.1 3.1 Phenomenon 3.2 3.2 Image method 3.7 3.3 Calibration 3.12 3.4 Experiment results 3.16 3.5 Discussion 3.29 Chapter 4 Theory 4.1 4.1 Governing equation 4.2 4.1.1 Rigid ceiling part 4.2 4.1.1.1 Shallow flow equation 4.2 4.1.1.2 Source terms 4.3 4.1.2 Floating foam raft 4.7 4.1.2.1 Shallow flow equation 4.7 4.1.2.2 Source terms 4.9 4.2 Eigenstructure 4.12 4.3 Internal boundaries 4.14 4.3.1 The transition of the dilute bubble and the dense foam 4.14 4.3.2 The transition between ceiling current and floating raft 4.14 4.3.3 Downstream end of the foam raft 4.15 Chapter 5 Computations and comparison with experiments 5.1 1.1 Numerical scheme 5.2 5.1.1 Flow operator 5.2 5.1.2 Transition criterion 5.5 5.1.3 Source operator 5.6 5.2 Calibration and choice of the numerical parameters 5.8 5.3 Numerical Results 5.10 5.3.1 The half-jet problem with the entrainment 5.10 5.3.2 Rigid ceiling with a slope break 5.11 5.3.3 Complete flow with ceiling current and foam raft 5.13 5.4 Comparison and discussion 5.14 Chapter 6 Conclusion and perspective 6.125810906 bytesapplication/pdfen-US氣泡流bubbly currentsthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/50203/1/ntu-95-R93521327-1.pdf