Resistance And Flow Field Research Based On V-shape Angle Transform Of NOBS

NOBS (No-Ballast-Ship) is a new type of green ship to reduce environmental hazards of ballast water. Compared with conventional ship, it is the most significant innovation of ship manufacturing concept until now, which can not only maintain the required draft, but also ensure the safe navigation of ocean-going vessels.The design objects of no ballast water ship are to meet the needs of the navigation performance without or with a little ballast water. There are three design types of no ballast water ship in the world, Through-Flow System Hull design, Monomaran Hull design and V-Shape Hull design. The development of V-Shape Hull design researched by Japan is the best. According to Japanese research, because of the reduction of the amount of ballast water and optimization of ship, the ship resistance can be greatly reduced. Based on the exiting NOBS research, it will be deep researched that the relationship of bottom V-shape angle and the resistance of V-Shape hull. Then the rule between the change of bottom V-shape angle and the corresponding change of its resistance will be presented. In addition, the flow field will be analyzed in example.The main job of this paper should include two parts. The first part is about the generation of model library which will be realized by the NAPA software. The establishment of the NOBS model will be transformed referenced Japanese V-shape NOBS design. At last, the length, breadth and draught of V-shape NOBS will be changed in the condition that displacement and block coefficient remain unchanged to research the change of bottom V-shape angle. The variation curve between bottom V-shape angle and ship breadth can be drawn.The second part of the paper is the resistance computation of ship models which will mainly based on the SHIPFLOW software. The prepared offset file of ship models will be imported to SHIPFLOW software, then the surface will be meshed, commend file will be edited, flow field will be analyzed, computation date will be collated and compared. At last, the result will be analyzed and the variation curve between bottom V-shape angle and ship resistance will be drawn, and the NOBS energy efficiency also be analyzed.Based on a large amount of calculation of V-shape models, the variation curve between bottom V-shape angle and ship resistance will be drawn, which will proved a reference for the determination of the bottom V-shape angle of V-shape NOBS design.