1. Wave making drag prediction for improved design of marine crafts
Fluid Structure Interactions Research Group
Wave making drag prediction for improved design of marine crafts
Mirjam Fürth– - Faculty of Engineering and the Environment
Supervisors –Dr. Mingyi Tan and Dr. Zhimin Chen
Background
With globalization and associated rising demand on transportation, the volume and size of the merchant fleet will also increase since the majority of goods are transported by sea.
In shipping, a significant cost both to the ship owners and the environment is the fossil fuels used for propulsion. With the rising price of oil and the growing environmental concern, the motivation to reduce oil consumption has never been higher.
Motivation
About 50% of the resistance of a fast container ship is due to wave resistance. This means that even a small reduction in the wave resistance can bring considerable reductions both in operating costs and emissions.
When designing a ship it is important to be able to make fast and accurate prediction of its resistance so that more efficient hull forms can be selected early in the design process. A RANS solver based CFD software is still too time-consuming to be adopted in the initial design process
Figure 1: Wave patterns behind a mallard[1]
Evaluation
The double integral in the Greens function can evaluated straight away since it has no singularities thanks to the Rayleigh viscosity.
According to thin ship theory the sources can be placed along the centre line of the vessel at half the depth. The wave pattern from a Wigley hull are seen in Figure 2 and 4 . The wave pattern behind a wedge shaped hull with constant draft is shown in Figure 3
Figure 4: Wave patterns behind a Wigley hull
Figure 2: Wigley hull Figure 3: Wedge shaped hull
Next step
Develop a panel method for 3D hulls.
Improve the speed of the algorithms.
Outcome
A fast and reasonably accurate method for ship wave drag prediction.
A tool for early hull design or optimisation, capable of taking some finer features into consideration.
References
FSI Away Day 2012
Acknowledgement
This project is supported by funds from the
Lloyd’s Register Educational Trust, through the
Lloyd’s Register University Technology Centre