고정된 2차원 직사각형 격자계에서 자유동요하는 물체주위 유동의 수치시뮬레이션

다국어 초록 (Multilingual Abstract)

In this research a numerical simulation method is developed for free surface flows around a freely oscillating body in fixed two-dimensional rectangular grid system. The non-linear free surface near the body is defined by modified marker-density method. The body boundary is defined by line segments connecting the points where the body surface and grid lines meet. Continuity equation and Navier-Stokes equations are used as governing equations and the equations are coupled with two-step projection method. The subgrid-scale turbulence model is applied in order to consider turbulence effects. To treat body movements in a fixed grid system. the volume displaced by moving body is added to the divergence of the body boundary cell. For the verification of the present numerical method, the vortex induced vibrations of an elastically mounted cylinder are calculated, and the amplitudes are compared with existing calculation results. Moreover, the free roll decay of a floating box is numerically simulated, and the results are compared with published experiment results.