Session: 08-01-02 Maneuvering Simulation

Paper Number: 126145

126145 - The Effect of Boundary Condition on Predicting the Thrust Loss of Azimuth Thruster in Ship-Type Offshore Structures 

For various offshore structures including ship type such as drillship, Wind Turbine Installation Vessel (WTIV), Floating Production Storage and Off-loading (FPSO) and Floating Liquefied Natural Gas (FLNG), the dynamic positioning (DP) is a fundamental and important operation. For effective DP operation, the special propulsor called by azimuth thruster was chosen in general. It is well known that several azimuth thrusters are installed in offshore structures, the thrust loss might be induced by various interaction phenomenon. So, these interaction effect on azimuth thruster have been investigated for a long time by various approaches for example, model test and CFD simulation. In this study, the influence of boundary conditions is mainly examined for predicting thrust loss in numerical simulation. And WTIV and FPSO were chosen as a target vessels. Two different types of boundaries in numerical simulations were defined. The first consideration is that the boundary condition was assigned with direction of the azimuth angle of the thruster whereas it is fixed regardless azimuth angle of the thruster. The predicted thrust loss according to these boundary conditions showed a difference and this is originated from the current load of the vessel. The current load on ship depends on the ship type, draft and inflow direction, the magnitude of current load is affected by that conditions. Since the current load might be induced unintentionally in numerical simulation, the boundary condition is important to obtain a realistic thrust loss. For obtaining the reliable results, the model test to predict the thrust loss on WTIV was conducted and compared to those from numerical simulation.

Presenting Author: Gisu Song Korea Maritime & Ocean University

Presenting Author Biography: Gisu Song is a professor of Korea Maritime and Ocean University. He worked in Samsung Heavy Industries for 12 years and mainly conducted a propeller design and numerical simulation.

Authors:

Jaehong Woo Korea Maritime & Ocean University
Gisu Song Korea Maritime & Ocean University
Joo-Sung Kim SAMSUNG HEAVY INDUSTRIES CO., LTD.