Calculation of the Coefficients of Ships Resistant Force in MMG Model Based on CFD

With the rapid development of computer, computer simulation is a reasonable way to study the maneuverability of a ship. The accuracy of ship motion mathematical model has a great effect on research results. The resistant coefficient is a crucial parameter to ship models rapidity. Hence, it is significant and practical to research how to calculate a precise resistant coefficient. This paper introduces the theoretical calculation of ship resistance coefficient and methods to get ships hydrodynamic force based on CFD theory. With the commercial CFD software Fluent, we make numerical calculation for sailing ship based on turbulence theories, and get the ships resistant coefficients of MMG (usually called Maneuvering Model Group) model. Instead of making traditional model-scale numerical calculation, we made full-scale distributed numerical calculation with high-performance computers. After comparing the calculation results with the real ships resistant coefficients, which were obtained by actual host power and ships velocity, there is a conclusion. The calculation results are very close to the real ships resistant coefficients, since the Reynolds number and the Froude number of calculation model are almost equal to those of the real ship. Computer simulations of ships circle turning were made respectively with the resistant coefficients we got and previous estimation formula of MMG model. The simulation result of calculated resistant coefficients was closer to real ships circle turning.