三次元離散渦法を用いた斜航船体周りの流場推定に関する研究

抄録

Present study applies a three-dimensional vortex method to estimate the flow field around a container ship in oblique motion. The three-dimensional vortex method which does not need the grid generaion as a pre-process is a Lagrangian method. The governing equations of the three-dimensional vortex method are vorticity transport equations and continuity equations. In order to solve the convection and diffusion term of vorticity transport equations, present study uses the operator-split algorithm proposed by Chorin. A discreted vorticity model used in present study is vortex blob which is a sphere type and has Gaussian distribution of vorticity. Core-spreading method which calculates the diffusion of vorticity by changing the radius of vortex blob is used and 2nd order Adams-Bashforth method which calculates the convection of vorticity is used. Three-dimensional Hess and Smith type panel method is used to estimate the initial flow field. In present study, flow fields around a container ship in oblique motion (β=3°, 6°, 12°) are shown as results of calculation and usefulness of three-dimensional vortex method is investigated.