Characteristics of ice formation and melting for latent heat thermal energy storage cell using resin tube-mat to prevent destruction by a volume increase of ice and corrosion of heat exchanger tube was examined by the numerical analysis. The numerical analysis is carried out with the enthalpy method does not need the special handling by the introducing latent heat term. The numerical results agree well with the experimental results. Influence on ice formation and melting was considered by the difference between the size (thickness of tube and diameter, etc.) and the physical properties of resin tube. Quantity of ice formation and melting is almost proportion at time. Thickness of tube greatly influences ice formation and melting. Ice formation and melting quicken as the thickness of tube thins. Ice formation speed increases as the inner diameter of tube grows. However, increase proportion at formation or melting speed becomes small as the inner diameter of tube grows. As a result, a basic characteristic of latent heat thermal energy storage cell using resin tube-mat was clarified.

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The bridging time and freezing phenomena of phase change material (PCM) around two horizontal tubes arranged in a vertical series were studied numerically. Water was used as the PCM. The aim of this study was to investigate an estimated bridging time of the solidification process. Bridging time was calculated by numerical method. To confirm the validity of the present numerical calculations, it was compared with results conducted by other researchers. As the first step toward the aim, the freezing phenomena and bridging time were investigated in detail and then approximated by quadratic functions with a non-dimensional distance between the two tube centers.

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書籍とインターネット情報源のメリットを最大限生かし、そのデメリットを最小化した、デジタル時代にふさわしい新しい知識構成体「ビヨンドブック（BB）」の開発に取り組んだ。そのために先ず過去の開発事例及びその問題点をレビューした。またそれを実施するための研究チームを、多様な分野からの人材で編成した。図書や資料が図書館やアーカイブの中核をなすように、デジタルアーカイブにとって、将来BBがコンテンツの中核を担うことが期待される。

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Many kinds of the air conditioning systems with ice thermal energy storage have been proposed so far, and among them a system with a water-embedded-type ice storage vessel, in which both solidification and melting occur on heat exchanger tubes, is widely used because of its simple structure and compactness. However, the water-embedded-type ice storage vessel has a disadvantage, that is, solidification rate is very small. The use of falling water film seems to be one promising ii way of solving this disadvantage. The sensible heat in water could be quickly extracted due to high heat transfer between the solid/liquid interface and the falling water film, and the solidification rate becomes larger than that in a usual water-embedded-type ice storage vessel. In the present study, we systematically investigated the influence of tube wall temperature, film Reynolds number of the falling water and initial water temperature on the solidification rate, and a correlation between dimensionless solidified area and dimensionless time was proposed. In addition, we compared the solidification rate obtained by using the falling water film with that obtained in the usual water-embedded-type ice storage vessel. It was seen that the use of the falling water film is very effective, especially for high initial water temperatures.

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Characteristics of the heat transfer with solidification of phase change material (PCM) around horizontal tubes immersed in working fluid were studied by numerically and experimentally. In this study, variations in the specific heat of the PCM are incorporated in order to account for the phase change. The body fitted coordinate system is used to compute arbitrary shape of tubes. Numerical results were compared with experimental results. Results are presented as transient freezing front contour of PCM, velocity field, temperature distribution of water and freezing fraction ratio.

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Experimental investigation was carried out on the flow patterns and rising velocity of gas phase in an ascending gas-liquid two-phase flow in an inclined pipe. Air and water were used as the working fluids, and the inclination angle was set to be 45°. The wettability of the pipe was varied by coating repellent on its inner wall. The boundaries between the bubbly flow, slug flow, and stratified flow regimes were not affected by the wettabiliy of the pipe. The boundary between bubbly flow and slug flow regimes was correlated as a function of the superficial velocities of gas and liquid. The rising velocity of gas phase increased as the wettability of the pipe became poor.

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Transient natural convection in water around a cooled horizontal cylinder placed in a rectangular enclosure has been studied. The governing equations were solved by a finite difference method, and the flow structure and temperature distributions have been predicted. The purpose of the present study is to examine the effects of the position of the cylinder and the initial temperature of water on the cooling process of water. The initial water temperature was varied at 4, 6, 8 and 12°C, and timewise variations of the temperature field and the velocity field as well as the mean Nusselt number on the cylinder surface were compared. The changes in the position of the cylinder and the initial water temperature largely affect fluid flows due to the density inversion of water. Complicated flow patterns are observed for initial water temperatures larger than 4°C. Therefore, the cooling rate of water is largely changed with the change in the position of the cylinder for initial water temperatures larger than 4°C.

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著者らはこれまでに飽和含水土壌の凍結速度に及ぼす土壌含水率，土壌の初期温度，凍結管冷却温度および土壌物性値などの影響について実験的に検討してきた¹⁾。本論文では凍結や融解を含む土壌内の温度分布予測のための数値モデルを提案し，数値予測結果と模擬土壌を用いた実験データや実際の地盤凍結工法で測定された測温データと比較を行いモデルの妥当性を検証した。その結果，このモデルでは冷熱源または温熱源が複数存在する場合や土壌の熱物性値が局所的に変化する場合，さらに地下水流が存在する系についても解析が可能であることが明らかになった。また，土壌の初期含水率，初期温度および凍結管冷却温度が凍結現象に及ぼす影響について検討した結果，特に土壌の初期含水率や冷却温度は凍結速度に大きな影響を与えることがわかり，また凍結が進むと各凍結管から成長した凍土同士が連結することで未凍結領域の冷却速度が低下し，その後の凍土の発達に強く影響することが明らかとなった。

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