Session: 06-04-02 Marine Engineering and Technology II

Paper Number: 125658

125658 - Calculation of Force-Coefficients of a Wind Propulsion System for a 4 Dof Velocity/power Prediction Program 

The forces generated by the wind propulsion system (WPS) are of fundamental importance to predict the performance of a wind ship respectively wind assisted ship. In the early design stage, the size, type and number of wind propulsion elements (WPE) must already be defined. Therefore, different configurations in position, size and type of WPE have to be considered. Especially the position of the individual wind propulsion elements has a great influence on the yaw moment generated by the entire WPS. This yaw moment must be adapted to the yaw moment caused by the drift motion of the hull. If the yaw moment, generated by the WPS can compensate for a large part of the hull-generated yaw moment, huge rudder angles can be avoided. In this case, the overall potential of the ship can be increased significantly.

The individual WPE affect each other. Consequently, the forces generated by the single elements cannot simply be added up to calculate the total force of the WPS. To be able to take these effects into account in the early design decisions, a fast method to calculate the forces of the whole WPS in conjunction with a fast velocity respectively power prediction program (VPP/PPP) is very important. In this paper, a method to calculate the force coefficients of a WPS consisting of single wind propulsion elements is presented. This method is based on potential theory in order to quickly obtain sufficiently accurate force coefficients, which are necessary for the VPP/PPP called “E4-SAIL”. This program balances the forces acting on the ship in the four degrees of freedom surge, sway, roll and yaw to evaluate the performance of the wind ship or wind assisted ship in an early design stage.

The paper is original and for the first time presented in public.

Presenting Author: Johannes Oettle Hamburg University of Technology - Institute of Ship Design and Ship Safety

Presenting Author Biography: The author graduated in 2021 in Naval Architecture and Ocean Engineering at Hamburg University of Technology. Since 2021 he works as a research assistant at the Institute of Ship Design and Ship Safety at Hamburg University of Technology.

Authors:

Johannes Oettle Hamburg University of Technology - Institute of Ship Design and Ship Safety
Stefan Krüger Hamburg University of Technology - Institute of Ship Design and Ship Safety