Research On Low-speed Ship Propulsion Database And Its Software Development

Propulsion system is the most important part of the ship's power plant and is also the source of ship power. Its performances directly influence the operation of the ship. Ship preliminary design stage is the main stage of ship design. To be sure of a product's main parameters, the main structure and main equipment selection is according to the designer, shipbuilding contract and through the theoretical calculation and the necessary test. However, in the preliminary design stage, knowing the parameters is limited and propulsion system involves many devices and the devices influence each other, so designers generally according to design experience and the mother ship type of propulsion system to design program and then select a better proposal from a serious of design proposal. So, if designers have too little information the mother ship or the equipment information is collected not finishing is not comprehensive, will not get a better proposal in a relatively short period of time.In this paper, according to the problems of design process of ship propulsion system which is talked above, built database of ship propulsion system and developed relatively software to realize the project design of computer aided design of ship propulsion system at the preliminary design stage so that designers could reduce the time of inquired the equipment information and data and improved the work efficiency. The main research contents are as follows:(1) Due to the situation that few parameters are known at preliminary design stage, this paper collected plenty of information about 2500 information of existing ship type(including bulk carriers, tankers and container ship) and stored these information in the database. Also collected equipments type of ship propulsion system and stored into the database, including main engine data, bearing information and Stern seal information;(2) Through researching the design method of ship propulsion system, sort out the selection method of propulsion mode using ship low speed engine and the equipment. Studying map design of propeller, estimate the power of main engine, calculating the diameter of axle and verify the strength of axle. This paper also introduced the indexes of main engine selection;(3) With Visual Basic.net programming language and ACCESS 2007 database for development platform develop the database and software for low-speed marine propulsion system. The system is mainly based on key technologies including the cubic spline interpolation method applied to the propeller in the map design; department of the Navy the power coefficient method to estimate the power of main engine; using multiple linear regression method to obtain the different formulas to estimated the power of main engine power; using AHP model for the program selected the preferred main engine;(4) Propulsion system of 26000DWT oil tanker was designed by this system, the results proved the feasibility of the system.