A numerical study on the flow considering the influence of moving objects under the free surface in marine engineering

Abstract

In a flow including a free surface, an interaction relationship between objects and the free surface is seen in many cases. In recent years, research on environmental change and protection has become active, so analyzing a flow field including the free surface is one of the major issues in river engineering and marine engineering. However, in most of the previous researches, the flow field was limited to the reproduction of the simple flow field. In this study, we dealt with the flow field including the free surface around a moving object with a complicated shape. So, in order to show the change of the shape of the free surface caused by the moving object, the Interface Tracking method was adopted. In this method, in order to express how the interface moves, it is necessary to move and deform the computational grid. Therefore, the calculation method was constructed based on the Unstructured Moving-Grid Finite-Volume method, which strictly satisfies the geometric conservation law and the physical conservation law. The NACA0012 blade was placed under the free surface, and the relationship between the blade's movement and the free surface was investigated. As a result, it was confirmed that the detail change of the free surface caused by the movement of the blade. Thus, it could be shown the promising feature of the computation.