Budget Amount *help |
¥16,380,000 (Direct Cost: ¥12,600,000、Indirect Cost: ¥3,780,000)
Fiscal Year 2019: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2018: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2017: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
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Outline of Final Research Achievements |
This study was aimed at developing a new analytical method for the external two-phase flow in the seawater, which contributes improvement of a ship drag reduction technology based on the air lubrication method. The database on local flow structures in the external two-phase flow under a model ship bottom was newly constructed through the experiment using a circulation water tunnel. Experiments for a single bubble and bubbly flows in the seawater were also performed to identify the characteristics of the interfacial drag of a single bubble and the bubble coalescence in the seawater. Based on the obtained experimental data and the analytical results, a modeling of the external two-phase flow was examined by taking the bubble layer thickness as a length scale and a new correlation for predicting void fraction under the ship bottom was successfully developed.
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