肥型船首まわりの渦流れを伴う流体現象のCFDシミュレーション

抄録

In the present studies, hydrodynamic phenomena with vortex flow around the bow of a blunt ship are simulated by using various CFD (Computational Fluid Dynamics) codes. In the conventional experimental studies, some flow properties in front of the blunt bow beneath the free surface have been found out and reported; for example, a necklace vortex based on the wave breaking phenomena is the typical one. In CFD simulations, however, reliable results have not been obtained yet. The authors pay attention to the free surface boundary conditions to carry out the numerical simulations by NS (Navier-Stokes) solvers in CFD codes. As NS solvers with the different free surface boundary conditions, two phase flow and double model flow solvers in OpenFOAM prepared as CFD tools box of open sources and one phase flow solvers of SURF, NEPTUNE developed by NMRI (National Maritime Research Institute) are used. As the results of two phase flow solver included in OpenFOAM above mentioned some flow properties with vortex flows can be obtained. Influences of the free surface boundary conditions to the vortex flow phenomena around the blunt bow are discussed in comparison with various results based on other NS solvers and experiments.