液體渦流與鐘擺物體交互作用之雷射發光實驗與無黏性流體計算

Interactions of solid particles and liquid vortices in inviscid flow computations and laser-illuminated pendulum experiments

許蕙麒(Huei-Chi Hsu)

指導教授 ： 卡艾瑋

國立臺灣大學/工學院/土木工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.02952

摘要

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。

關鍵字

渦流 ； 雷射 ； 粒子影像 ； 柏努力方程式

並列摘要

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.

並列關鍵字

vortex ； vortex pair ； PTV ； laser ； bernoulli equatiion

參考文獻

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