Numerical Simulation of Tidal Current or Wind Over the Sea and Applications to Navigational Simulation of a Sailing Ship

This paper deals with numerical estimations of the ocean surface wind and tidal currents in a bay. Such estimates are very important because the wind and tidal current react to environmental factors, such as the effects of a marine structure or a sailing ship. The final object of this research was to develop a weather routing system for small vessels in coastal water. First, a computer simulation of tidal current was carried out in the same bay in Japan. The results showed that tidal simulation was very effective for the weather routing system of a small vessel. Next, an estimation of the ocean surface wind was carried out in Osaka Bay using the MM5 mesoscale meteorological model. A comparison of the calculated numerical results with the observed ones was confirmed that the ocean surface wind in Osaka Bay was accurately estimated. Third, as an application of the estimation of wind or tidal current in the bay, navigational simulations of a sailing ship under the effects of the wind or tidal current were conducted using the numerical data of the ocean surface wind or tidal current separately. The importance of this simulation method for ship positioning was confirmed, as was the accurate estimation of the effects of wind or tidal current in coastal water on a sailing ship in a navigational simulation for optimum weather routing.