本研究では成層流体中気泡プルームの挙動について、溶解のない気体であるAirと溶解のある気体であるCO2を気泡として用いて室内実験を行い、気泡流量、成層の強さ、気泡径と貫入高さとの関係について調べた。その結果気泡径の貫入高さに与える影響が、過去の研究とは異なり、気泡径が大きくなるほど貫入高さは高くなる傾向が見られた。また、新たに基礎的な無次元数を導入し実験結果の整理を行った。また気液二相流の数値解析法による解析結果と実験結果とを比較し、この数値解析法の有効性を確認した。

　

　The 3D flow fields around a Tidal-Jet Generator (TJG) are investigated in a tide-like oscillating flow using a finite-difference numerical scheme, named NS-MAC-TIDE based on the fully 3D Navier-Stokes (NS) equations. The TJG is an enclosed rectangular breakwater, which has vertical opening and a large enclosed volume inside. During both phases of tide, strong and uni-directional jets can be obtained locally from the inlet of the TJG, due to the water level difference between the inner and outer sides of breakwater.

　The NS-MAC-TIDE model is applied to predict the maximum jet velocity at inlet and to reproduce the characteristics of flow field around a TJG. It is also obvious that the numerical simulations can reproduce successfully the processes of generation, development and dissipation of tide-induced jets.

　

　In the CO2 sequestration in the deep ocean, the analysis of mass transfer at the interface between CO2 droplets and seawater is very important. A CFD code based on unstructured mesh consisting of tetrahedrons and triangular prisms has been developed. The prisms are generated along body boundaries to resolute momentum boundary layers. In high Schmidt number problems, mass boundary layer is much thinner than that of momentum so that very thin layers (VTL) are generated in one layer of prisms attached to the interface only for solving mass transfer. The Sherwood numbers of a solid sphere are obtained in our numerical experments and are in good agreement to available empirical equation.

　

　壁の放射熱伝達と熱伝導の影響を考慮したLESによる乱流状態の対流熱伝達に関する3次元の数値解析法と放射吸収係数の算出を含む放射熱伝達の計算法を開発し、さらにこの数値解析法の検証のために、コンテナ型の断熱室の壁体内部に発熱体を埋め込んだ放射壁面を設けて熱伝達実験を行った。これらにより、区画内熱伝達に関する壁の熱放射及び壁体熱伝達の影響を調べた。