卡艾瑋臺灣大學：土木工程學研究所許蕙麒Hsu, Huei-ChiHuei-ChiHsu2007-11-252018-07-092007-11-252018-07-092005http://ntur.lib.ntu.edu.tw//handle/246246/50299本論文之研究目標為浸沒物體與液體的交互作用。這是首次研究一個或兩個緊密球體在液體中擺盪與液體交互作用的鐘擺實驗，本實驗中包括了特別的球碰撞實驗等等。由於使用的透明球體與液體兩者的折射率互相類似，因此本實驗可以在三維流場中得到完整的二維切面。此外，本實驗利用長時間曝光影像與PTV方法描繪出液體中微粒的散佈，其中運動球體周圍的流體運動可以明顯的發現是渦流與非旋流體流場的疊加。基於此實驗觀察，本論文將此現象條件簡化為二維無黏性流體，藉此建立一個數值計算，並且應用到理想流體中剛體與流體的運動。The present thesis focuses on interactions between solid particles and the liquid in which they are submerged. These interactions are first probed in the laboratory using pendulum experiments: one or two dense spheres are suspended by thin strings and induced to oscillate inside the liquid. The cases examined include in particular the collision of one sphere with another. Laser-illumination and refractive index matching of the transparent solid and liquid materials are used to obtain unhindered views of selected 2D slices cut through the 3D flows. Long exposure images and particle tracking velocimetry are used to characterize the motions of microparticles dispersed in the liquid. The liquid motions around the moving spheres feature distinct vortex motions superposed onto an irrotational flow. Based on these observations, simplified 2D inviscid flow computations are set-up and applied to idealized flows involving coupled solid and liquid motions. In particular, the motion of a disk induced by the passage of a vortex pair is examined.Table of contents 誌謝 1 摘要 2 Abstract 3 Table of contents 4 Figure list 5 Table list 6 1. Introduction 1.1 2. Experimental apparatus and imaging methods 2.1 2.1 Experimental set-up 2.2 2.1.1 Equipment 2.2 2.1.2 Liquid 2.5 2.1.3 Particle 2.5 2.1.4 Experimental procedure 2.7 2.2 Laser off-center problem 2.8 2.3 Long exposure visualization 2.12 2.4 Particle tracking velocimetry (PTV) 2.15 3. Experimental results for one and two spheres 3.1 3.1 Experimental conditions 3.2 3.2 Results for single pendulum 3.4 3.3 Results for two spheres without collision 3.11 3.4 Results for the collision of two spheres 3.17 3.4.1 Before collision 3.17 3.4.2 After collision 3.22 4. Inviscid flow simulations 4.1 4.1 Dynamic analysis 4.2 4.2 Energy analysis 4.5 4.3 Simulation results 4.7 4.3.1 Single pendulum 4.7 4.3.2 Vortex pair moving obliquely past a pendulum 4.8 4.3.3 Vortex pair moving past a fixed cylinder 4.13 4.3.4 Vortex pair interacting with a free cylinder 4.15 4.3.5 Vortex pair moving past a pendulum 4.18 Conclusions 5.1 References27529215 bytesapplication/pdfen-US渦流雷射粒子影像柏努力方程式vortexvortex pairPTVlaserbernoulli equatiionthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/50299/1/ntu-94-R92521327-1.pdf