Research On Design Method And Resistance Performance Of V-Shape Non-Ballast Water Ship

At present,there are a large number of goods in the world that rely on ships to transport,but ships need to carry a certain amount of ballast water to ensure normal navigation.However,ballast water is detrimental to human health,social economy and ecological environment.In response to the problem of ballast water,relevant international organizations and countries have introduced laws and regulations governing ballast water.Some ballast water treatment technologies have also emerged,but these cannot fundamentally solve the problems caused by ballast water.Therefore,researchers in some countries have proposed the of a Non-Ballast Water ship in order to thoroughly solve the problem of ballast water.Nowadays,there are three kinks of design for Non-Ballast Water Ship: the Japanese V-Shape NOBS(V-Shape Non-Ballast Water Ship),the US Through-Flow System Hull,and the Dutch Monornaran Hull.Based on V-Shape NOBS,this paper takes the 26000 DWT tanker as the research object,improving the lines design method,developing the rapid lines design and rapid modeling system,and analyzing the resistance performance of design ships.Firstly,based on the invariant method of the cross-sectional area of the mother ship,a flat part can be generated at the V-shape bottom by improving the design method of the V-shape NOBS,which makes the design better meet realistic demands.After the proposal of line design method,the data of the design ship breadth is statistically selected,and the relationship between breadth,bottom inclination angle and the flat keel is obtained.We can plot the lines at each bottom inclination quickly through the secondary development on AutoCAD by VB to meet the demands of smooth lines.Secondly,based on the new lines rapidly obtained,the CATIA software is secondary development to achieve the rapid modeling and the extraction of hydrostatic elements of V-Shape NOBS.Through the statistical analysis of hydrostatic elements,the difference of hydrostatic elements between V-Shape NOBS and mother ship can be contrasted,and the variation that hydrostatic elements of V-Shape NOBS change according to bottom inclination angle can be obtained,which can provide a reference for V-Shape NOBS design.Finally,based on the rapid modeling of the V-Shape NOBS,the resistance performance of the V-Shape NOBS is studied by using the CFD numerical calculation method.By comparison of resistance calculated by CFD with the resistance experiment value of the mother ship,it shows that the calculated results of STAR-CCM+ can meet the accuracy requirements.By comparing the resistance of the V-shape NOBS with that of the mother ship,the resistance characteristics of the V-shape NOBS are obtained,and the variation that the total resistance and resistance component of the V-shape NOBS changes according to bottom inclination angle can be analyzed.In order to better design the V-shape NOBS and reduce the resistance,this paper studies the influence of the length and the maximum breadth of the bulbous bow on the resistance of the V-shape NOBS by changing the length and the maximum breadth of the bulbous bow.