Research On The Structure Optimization Of Double Bottom Of Fishing Boats Based On Oil Leakage Prevention

Nowadays, China has more than 1,000,000 fishing boats, and is the country with the largest number of fishing boats. But the fishing facilities of china is enormously backward on the whole. In the meantime, the fishing method and the processing method of the fishing product are all on the lower level in the world. Although china has lots of fishing boats for the fishing industry, the quality of these fishing ships is relatively low. Most of them are dangerous and old ships. Thus, there is no guarantee for the safety of these fishing personnel. At the same time, China’s economic development is at a crucial stage for international economic, political and sustainable development, with pressure and competition existing at the same time, therefore protection for resources and the environment for fishery production and energy saving and emission reduction, and promotion of healthy development of ship manufacturing are very important. With the increase in the number of ships, oil leakage accident situation also will increase, for pollution prevention and safety operation of ship and other reasons, research of underwater oil leakage of damaged double hull boats has certain practical significance.In this article, the oil tank of pelagic fishing boat with double bottom structure is selected as the prototype of experimental model. Design structure of longitudinal framing is used for the ship, oil tanks are placed symmetrically to the longitudinal profile symmetry of ship, above the middle bottom stringer of ship. the leakage mechanism of underwater oil leakage of double bottom fishing boats, the flow process of oil-water mixture within the double bottom, the leakage blocking effect of the internal structure of the double bottom fishing boat and its optimization is researched and discussed. In this article, the research results will help to further understand the leakage blocking mechanism and the influence factors of internal structure of the double bottom, which will have some guiding significance for the effective prevention and reduction of marine oil leakage, and will have some reference values for the optimization of the internal structure of the double bottom fishing boats and the design of ship, so as to contribute to the safety of ship, and win precious time to take rescue measures. The research methods of numerical simulation andmodel test are combined to focus on the analysis of the internal structure of the effect of double bottom ship on oil leakage, with mainly the following aspects of work:(1) firstly similarity theory is used to construct models, appropriate three-dimensional numerical simulation is taken according to the physical model. Then the two results were compared and analyzed and then verified with each other.(2) through the model test methods, the effects of internal structure of the double bottom ship on oil leakage is carefully analyzed for the leakage process, then the leakage blocking mechanism of double hull structure is discussed.(3) Through the three dimensional numerical simulation experiment, the internal main structure of the double bottom fishing boats(solid ribbed plate, lightening hole) will be optimized through three-dimensional numerical model test.Combining the two methods of numerical simulation and model experiment, the following conclusions are obtained in this article:(1) the internal main structure of double bottom fishing boats has significant influence on leakage.(2) The internal structure of the double bottom fishing boats can not only enhance the strength of the structure, but also has certain blocking effect on the oil leakage.(3) The smaller the distance between solid ribbed plate, the better the blocking effect; the lesser the number of lighting holes, the better the leakage blocking effect.