At present, the numerical simulation of the maneuvering characteristics of a newly-designed ship relies on hydrodynamic coefficients, which are mostly obtained from potential flow solutions in practice. These methods concentrate on an appropriate approximation of hydrodynamic forces rather than on the detailed structure of the flow field. They require empirical parameters, such as the point of flow separation or the location of the free vertex. Therefore, a tool which resolves the details of the flow field and evaluate the forces and moments with sufficient accuracy is necessary. The method used here, coupling the RANS (Reynolds-averaged Navier-Stokes) equations with rigid body dynamics, can be answer to this problem. The commercial CFD (computational fluid dynamics) code Comet is employed for the prediction of fluid flow. It is based on the finite volume method and can accommodate many types of finite volume cells (with as many as 16 faces), thus being applicable to complex geometry problems. The interaction of fluid flow and body motion is captured by coupling the equations of the body motion to the fluid flow analysis via the user-coding interfaces, then solving the equation system iteratively. The free surface is modeled by a interface capturing method, employing the HRIC (High Resolution Interface Capturing) scheme. Moving grids are used to realize new positions of the moving body. The method has the advantage of requiring no linear approximations so that it is suitable for the analysis of viscous flow fields with strong nonlinearity, such as the flow field around a maneuvering ship. For simulating maneuvering motions of ships by the present method, three steps are necessary from a CFD point of view. The first step is to model the flow about a rudder and a propeller individually, where the flow around a rudder is solved by CFD and the propeller is modeled by a body force model at its position. The forces on a three-dimensional rudder are predicted for a rudder alone and a rudder with a rudder-fin under inflow conditions of different angles of attack. The second step is the coupling of propeller and rudder and also their interaction with a hull coupled by CFD but with no ship motion involved. The final step is to simulate the maneuvering motion of the complete ship, such as drift motion, turning circle maneuver and zig-zag maneuver. The integrated system of propeller, rudder and ship was investigated considering the RoRo ship designed by Flensburg Schiffbau Gesellschaft (FSG) with twin propellers, twin spade rudders and fixed fins in the model scale of 1/34. The model tests have been performed at HSVA at a constant ship speed and a constant propeller speed. The inward-counterrotating propellers were simulated by a body-force distribution model. Comparison of theoretical and experimental results shows that by coupling of RANS and body-force model the basic principles of interaction of hull, propeller and rudder can be simulated with sufficient accuracy. The container ship CBOX, also designed by FSG, was chosen for the model tests (model scale 1/29 at HSVA) and simulations of the ship maneuvers mentioned above. The results show that the unsteady simulations can model the ship in maneuvering and/or waves.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Simulation of ship motions during maneuvers


    Additional title:

    Simulation von Schiffsbewegungen beim Manövrieren


    Contributors:

    Published in:

    Publication date :

    2006


    Size :

    24 Seiten, 29 Bilder, 8 Tabellen, 20 Quellen



    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English




    Simulation of Ship Motions during Maneuvers

    Xing-Kaeding, Yan / Jensen, Gerhard / AEROTEC Engineering GmbH et al. | Taylor & Francis Verlag | 2006


    Simulation of Ship Motions during Maneuvers -

    Xing-Kaeding, Yan | Online Contents | 2006


    Efficient simulation of ship maneuvers in waves

    Schoop-Zipfel, Jochen | DataCite | 2017


    Efficient simulation of ship maneuvers in waves

    Schoop-Zipfel, Jochen / Technische Universität Hamburg-Harburg / Technische Universität Hamburg-Harburg, Institut für Fluiddynamik und Schiffstheorie | TIBKAT | 2017

    Free access

    Efficient simulation of ship maneuvers in waves

    Schoop-Zipfel, Jochen / Technische Universität Hamburg-Harburg / Technische Universität Hamburg-Harburg, Institut für Fluiddynamik und Schiffstheorie | TIBKAT | 2016