GLRANKINE

Development of a 3D-Method for the Calculation of Ships’ Seakeeping

Status

completed

Scientists

Prof. Dr.-Ing. Bettar Ould el Moctar
Dr.-Ing. Alexander von Graefe

Project Description

For the ship designer it is important to know and optimise the seakeeping behaviour of ships in rough weather conditions. During the design process, efficient numerical methods are essential to reduce the computational cost and increase the number of conducted calculations. This allows to optimise hull lines for specific operational scenarios. Often these methods are based on potential theory. Assuming an ideal fluid (non-viscous, incompressible and irrotational) the Navier-Stokes equations can be simplified in such way that only the Laplace equation needs to be fulfilled inside the fluid domain. The aim of this project was to further develop a flow solver based on potential theory. The Laplace equation is fulfilled analytically by using Rankine sources distributed on the domain boundaries (boundary element method). To calculate wave loads, the stationary forward speed and periodic seakeeping problem are coupled. The further development especially focused on numerical and algorithm improvements as well as on the calculation of ship-ship interactions., see Figure 1.

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Figure1: Wave pattern of two ships with forward speed
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Funding

Funded by DNV-GL
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Publications
  1. von Graefe, A., 2014. “A Rankine Source Method for Ship-Ship Interaction and Shallow Water Problems”. PhD Thesis, University of Duisburg-Essen, March
  2. von Graefe, A., Oberhagemann, J., Shigunov, V., el Moctar, O., "Linear and Nonlinear Sectional Loads with Potential and Field Methods", Proc. 32nd ASME Int. Conf. on Ocean, Offshore and Arctic Engineering OMAE2013, Nantes, France. –Paper No. OMAE2013-10544
  3. von Graefe, A., Shigunov, V., el Moctar, O., "Rankine Source Method for Ship-Ship Interaction Problems“, Proc. 32nd ASME Int. Conf. on Ocean, Offshore and Arctic Engineering OMAE2013, Nantes, France. –Paper No. OMAE2013-10810
  4. Söding, H., von Graefe, A., el Moctar, O., Shigunov, V., “Rankine Source Method for Seakeeping Predictions”, Proc. 31st ASME Int. Conf. on Ocean, Offshore and Arctic Engineering OMAE2012, June 10-15, Rio de Janeiro, Brazil. –Paper No. OMAE2012-83450


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