The presence of bubbles within liquid pools is ubiquitous in many natural and industrial settings. Plants and other living systems can release gas bubbles which detach and rise up through lakes and the ocean. Degassing also forms gas bubbles on solid surfaces inside the liquids, like that from champagne or poured soda drinks. The bubbles eventually rise to the pool surface, where they can bounce or pop into the air. The detailed dynamical interaction of the bubble and the free surface can be greatly affected by any impurities on their surface, which can affect the mobility of the free surface. In this dissertation, we use both experiments and numerical simulations to study these hydrodynamics. First, we study the rise and bouncing of bubbles or water droplets from the free surface inside a perfluorocarbon liquid. From all four different configurations of mobile/immobile interface pairs we show that the mobile interface always induces stronger bouncing but faster coalescence. The bouncing enhancement ratio between mobile and immobile interface is $1.8\pm0.1$ for bubbles and $1.5\pm0.1$ for water droplets, with the size range from $250 \, \mu m - 550 \, \mu m$ for bubble and $600 \, \mu m - 1200 \, \mu m$ for droplet. Then the top phase is replaced with a glass plate to eliminate the influence from other internal properties besides surface mobility. Since our numerical simulations perfectly reproduce the experiments, we extend our simulations to the free frontal collision of two equivalent droplets. The results not only support our previous conclusions but also predict another peculiar second-collision phenomenon under certain conditions. Then we replace the surrounding liquid with more practical ones of water and ethanol. In extra-pure water, we find that a millimeter-sized bubble has a mobile interface. We add arachidic acid on the top surface to further investigate bouncing from an immobile interface without changing the interfacial tension. The bouncing enhancement by mobile vs immobile interfaces is once again verified for the water-air interface. For millimeter-sized bubbles, as we increase the bubble size from $780 \, \mu m - 1550 \, \mu m$ the bouncing enhancement ratio decreases from 1.8 to 1.2. Finally, we look into the bubble shape and evolution of the liquid film profile during the bouncing from a top glass substrate, using interferometry and numerical simulations. We use 640 nm laser interferometry with a maximum thickness resolution of 120 nm. The center-of-mass trajectory and film profiles are measured for the first bounce of bubbles between 0.8 mm to 1.2 mm. Then we compare the 1.48 mm bubble impact on a no-slip top wall with the SRYL model prediction, where they shared the same dimple diameter but have a non-trivial deviation in dimple depth. Lastly, we simulate the frontal collision between two identical 1.45 mm bubbles, which have complex multi-dimple formations during the bouncing process.

付記する学位プログラム名: 京都大学卓越大学院プログラム「先端光・電子デバイス創成学」 / 京都大学 / 新制・課程博士 / 博士(工学) / 甲第23431号 / 工博第4886号 / 新制||工||1764(附属図書館) / 京都大学大学院工学研究科電子工学専攻 / (主査)教授 白石 誠司, 教授 木本 恒暢, 教授 引原 隆士 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Computational Field Simulation processes are typically complex and involve execution of multiple software tools in the form of pipelines to perform simulations successfully. Very often, handling the input and output communication between the tools and allocating computing resources for the processes becomes an essential but an unimportant task for the user. A well written script can often reduce these peripheral tasks and allow the user to concentrate on the analysis. This thesis studies the aspects of design and implementation of a framework called the Integrated Simulation Environment or ISE, that not only forms a scripted environment for high level integration of simulation software tools, but is also flexible enough to accommodate new tools on the fly, while maintaining ease of use and reliability. A hierarchy based design methodology was used to implement the ISE. Hierarchies provide the framework with the flexibility to decompose the complexities of simulation process pipelines and physical entities such as grids and geometries into managable components. Also hierarchies are easily translated into standards such as XML for saving and restoring, and external communication. An Overset CFD simulation process pipeline was integrated into the framework and tested for ease of use, reliability and extensibility. Both simple and complex tools such as a curve extraction tool, a surface grid generation tool, a volume grid generation tool and tools for preparing flow solver inputs were integrated into the system and tested successfully.

A new high-resolution spatial discretization scheme is presented for use within the volume-ofluid (VOF) method. This scheme is an adaptation of the previously published boundary gradient maximization (BGM) scheme, with an extension for time-dependent solutions. The scheme does not explicitly reconstruct the interface, but rather resolves the values of the volume fraction in the area of the interface. The scheme is upwind biased to provide numerical stability, and the face values are limited to meet boundedness criteria and prevent variable overshoot. Unlike most other high-resolution schemes found in the literature, the proposed scheme does not use upwind-biased and downwind-biased “switching” to maintain stability. This thesis presents a number of test cases including 2-D and 3-D cases on both structured and unstructured grids. The results display the method’s ability to predict good shape of the volume fraction interface and resolve the volume fraction discontinuity.

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The General Purpose Interface Bus, as defined by the IEEE Standard, deals with systems that require digital data to be transferred between a group of instruments. An overview of this standard is presented which summarizes the interface's capabilities, functions and versatility by explaining the basic interface concepts. In addition, a GPIB testing application and a GPIB related design example are presented and investigated.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Uma interface com o usuário é composta por duas "vias" de comunicação, uma que vai do usuário até o sistema e outra que vai do sistema até o usuário. Cada uma destas "vias" possui um formalismo que define a comunicação associado. Neste trabalho, estes formalismos são descritos com uma gramática de atributos. Esta gramática foi expandida de forma a permitir a definição dos elementos que compõe a interface do usuário, e da estrutura que irá controlar a seqüência de execução das tarefas oferecidas pelos sistemas de aplicação. Ao longo do trabalho são discutidas algumas técnicas de descrição do formalismo de comunicação entre interface e sistema, são abordados os estilos de interação e apresentada as expansões aplicadas sobre gramáticas de atributos. Um exemplo auxilia a compreensão do uso da linguagem proposta, e um protótipo permite a validação das definições. / A user interface is composed by two "ways" of communication, one from the user to the system and the other linking the system to the user. Each of these "ways" has it's own mechanism. In this work, these mechanisms are described through an attribute grammar. This grammar has been expanded to allow the definition of the structure of the interface elements and the control of the execution of the tasks that the application system implements. Through this work, technics that describe the communication between the interface and the system, interaction styles and the extensions made on attribute grammar are discussed. An example is given to explain the use of the proposed mechanism and a prototype validates ideas discussed.

Uma interface com o usuário é composta por duas "vias" de comunicação, uma que vai do usuário até o sistema e outra que vai do sistema até o usuário. Cada uma destas "vias" possui um formalismo que define a comunicação associado. Neste trabalho, estes formalismos são descritos com uma gramática de atributos. Esta gramática foi expandida de forma a permitir a definição dos elementos que compõe a interface do usuário, e da estrutura que irá controlar a seqüência de execução das tarefas oferecidas pelos sistemas de aplicação. Ao longo do trabalho são discutidas algumas técnicas de descrição do formalismo de comunicação entre interface e sistema, são abordados os estilos de interação e apresentada as expansões aplicadas sobre gramáticas de atributos. Um exemplo auxilia a compreensão do uso da linguagem proposta, e um protótipo permite a validação das definições. / A user interface is composed by two "ways" of communication, one from the user to the system and the other linking the system to the user. Each of these "ways" has it's own mechanism. In this work, these mechanisms are described through an attribute grammar. This grammar has been expanded to allow the definition of the structure of the interface elements and the control of the execution of the tasks that the application system implements. Through this work, technics that describe the communication between the interface and the system, interaction styles and the extensions made on attribute grammar are discussed. An example is given to explain the use of the proposed mechanism and a prototype validates ideas discussed.