抄録
Flows around ships have various kinds of multiphase flows because ships move at the interface between air and water. The first example is free-surface waves generated by an advancing ship. The phenomenon can be simulated using CFD based on NS solvers, and the comuted wave pattern and the wavemaking resistance agree well with measurements. The second example is wave impact generated at the bow of a ship running in waves. In this example, the flow becomes a multiphase flow type with foams or bubbles. The third example is propeller cavitation, which is an evaporation process at normal temperature. On a full-scale propeller, the cavitation consists of bubbles, which cause erosion in the collapsing stage. The last example is microbubbles for the reduction of frictional drag, the major part of ship's drag. The microbubbles are quite effective in the reduction, but further study is needed for its practical use.
