Motions of an unmanned catamaran ship with fixed tandem hydrofoils in regular head waves
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Hydrofoils are approved of having the ability to help the propulsion of ships, and have been applied to many ships as an auxiliary propulsion system. However, in this paper, a novel unmanned catamaran ship completely driven by hydrofoils is proposed, which could navigate in the sea for a very long time at low speed as a mobile ocean observation platform. The hydrodynamics of this ship is systematically investigated through numerical simulations. First, the potential theory and the CFD method based on FLUENT for ship motion analysis are introduced. Second, the validation of the two numerical methods is carried out by comparing the results of heave and pitch motions for the case of the unmanned ship without hydrofoils. Finally, the CFD model of this unmanned ship is established and analyzed, and the interactions between the ship and hydrofoils are considered. The effects of the hydrofoils on ship motion under different wave conditions with low forward speed are analyzed. The results show that the horizontally fixed hydrofoils can significantly reduce the ship’s heave and pitch motions within a certain encountered wavelength range. It indicates that this unmanned catamaran ship with the horizontally fixed hydrofoils has good seakeeping performance.
KeywordsTandem foils Thrust Unmanned ship Seakeeping performance
This research is co-financed byGuangdong provincial department of science and technology (Grant no. 2014A020217001), National Key R&D Program of China (2016YFC1400202) and the special fund of Guangdong Provincial department of ocean and fisheries (A201501D06).
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