The Research Of Design Method Of Tunnel Stern Of Inland Full Scale Shallow Draft Ship

Inland shipping has played a very important role in the promotion of communication, economic development, social progress. River cargo ship, as the main inland shipping has played a critical role. With the development of the society and economy, logistics require much more growth of the cargo transportation. In order to obtain a greater amount of tonnage growing during this context, the scale of the river cargo ship is growing rapidly. With limited draught, it is that the length and breadth of the river cargo put the scale growth forward. River cargo ship gradually developed into full-scale shallow draft ship.It has been proved by many times that the full-scale shallow draft ship show a great quality in economy than other river cargo ship. But the new ship style also brought new difficulties in ship design. The main problem in the design of the full-scale shallow draft ship is how to compensate the thrust insufficiency in the trends of large-scale while keeping enough displacement required by the ship style. This problem is mainly reflected in the design of the ship stern. The design of the ship stern involves many factors to consider:in addition to meet the requirements of the propeller thrust to provide adequate space outside diameter, but also to improve propeller wake, to improve the propulsion efficiency and reduce resistance and so on. With good performance and economic advantages, tunnel-type stern will be paid more attention in the future. Therefore, it's of great practical significance to develop a type of tunnel stern which is suitable for the full-scale shallow draft ship.In this paper, the design characteristics of the tunnel-type stern have been researched. The masked method is applied to the generation of the tunnel stern surface. The change of the characteristics of the shape control lines drive the change of the characteristics of the tunnel stern surface shape, from which it's possible to achieve the qualified tunnel stern surface shape. Based on the conventional tunnel stern type, by changing the characteristics of the shape control lines, a fuller tunnel stern type was got. This tunnel type can maintain not only a wealthy displacement, but also can provide the propeller adequate space for larger diameter, which is more suitable for the shallow draft ship. The use of parametric design based on CATIA as the design platform, VB as programming language developed this tunnel type of parametric design procedures, the tunnel stern surfaces of parametric design. And the tunnel tail surface area as the target, this tunnel type for the parameter optimization.