Numerical Prediction Method Research Of Ship Self-propulsion Performance Based On Hull-Propeller-Rudder System

When ship sailing in the water, its pros and cons depend not only on its own characteristics, but also are closely related with propeller and rudder after propeller. As the main ship impeller,whether the propeller match ship has an important influence on the rapidity and economy of ship.Rudder after propeller plays a vital role in ship stability and direction adjustment. When researching ship's performances,we should not only focus our attention on the ship itself, but also need to consider the impacts of the complete system composed of hull, propeller and rudder.Further research of ship's performances under propeller-hull-rudder interaction plays an important role in ship optimization and design, which has a great theoretical and engineering significance.Base on computational fluid dynamics software Fine/Marine, the thesis takes KCS hull, KP505 propeller and rudder as the objects.With the method of being modeled geometrically, the computations are carried out, such as resistance test, propeller-open-water test, ship self-propulsion motion study with and without rudder, ship turning motion study.The key of ship self-propulsion numerical simulation is how to realize the mutual coupling between hull,propeller and rudder. With the technology of mesh with body and sliding mesh based on the Fine/Marine software, this paper builds a new rudder oars numerical solution coupling model and method, the movement of the ship is not caused by a given equivalent substitution to flow but directly by the thrust generated by rotation of the ship propeller which is in line with the actual situation. On the basis of the above, this paper carries out real-time numerical calculation of the ship 's self- motion at different propeller speeds. The whole process of the ship from the start to the stabilization of self-propulsion is simulated, and then the effective self-propulsion point of the ship under the test speed is obtained. The comparison between the results of CFD prediction of the ship's self-propulsion point and related test results shows that this propeller-hull-rudder interaction numerical solution model and method can accurately simulate the ship 's self-propulsion. According to the numerical results, the interaction between the ship and the ship's propeller and the interaction between the ship and the propeller and rudder are analyzed.Ship's turning motion study is also based on this propeller-hull-rudder interaction numerical solution model and method. By changing the initial rudder angle, the whole process of ship turning movement is numerical simulated.In this paper, the ship turning motion after given two rudder angles ?r=20° and 35° were numerical simulated, ship turning motion curves were drawn after getting ship turning motion characteristics are given. The numerical result was in good agreement with the results of the experience formula of the H-Songhai, thus verifying the reliability of the propeller-hull-rudder interaction numerical solution model and method for researching ship turning motion in this paper.In this paper, propeller-hull-rudder interaction numerical solution model and method have been established through conducting a numerical prediction research of ship self-propulsion performance and turning motion performance. It can be used to conduct numerical prediction researches of ships' complex motions in the water and offers reliable analytical methods of ships' optimization and design.