Parametric Design Method Research Of Bulbous Bow

Since the 1960s, following the bulbous bow used in the modern ships' transportation widely, the design of bulbous bow also obtained recognition of domestic and foreign research. The practice indicated that using appropriate bulbous bow can improve ships' resistance performance obviously, thus reduces the cost of transportation greatly. When selecting the bulbous bow, we must take into account the various aspects factor, such as structural strength, linear, navigation performance, efficient and so on, here we will only consider the linear parts of the bulbous bow emphatically. The traditional design of bulbous bow uses the atlas method, the process is tedious, moreover changes a parameter, often needs from the beginning to start to design again, therefore it is valuable how to facilitate simply design high performance bulbous bow.The type of the bulbous bow are numerous, through collecting large numbers of material, it is not difficult to find that, actually the profile of bulbous bow basically is the convexity surface, we can divide the bulbous bow into the U bulbous bow and V bulbous bow, each type of ships' bulbous bow' linear will be quite similar, the parameter relatively will be closer , therefore completely possibly carry on its classification the research, finally will achieve the goal that assigns the main hull characteristic parameter, then can produce a bulbous bow line automatically, and can be only suitable with the main hull the transition, This may reduce person's labor greatly.This article uses the parameter method, firstly, assigns the bulbous bow characteristic parameter, uses elliptic arc and biquadratic multinomial combined type fits the characteristic profile, then assigns bulbous bow with the main hull transient curve in several value spot, obtains the transient curve by three B transects. Obtain the lateral boundary line and the longitudinal boundary line before various cross profiles' boundary point and the bulbous bow's vertex. By various water lines and the profile point of intersection, the boundary line, obtains the water line chart. Taking a series of values of the characteristic parameter in specifically range, it may obtain a series of bulbous bow' line. This article has not involved the research of bulbous bow' performance, therefore has not been able to carry on the optimization to a bulbous bow' line, then choose the best bulbous bow.In the sixth chapter, it takes the 16000T cargo ship as the example, uses V bulbous bow to carry on the contrast, and adding bulbous bow to the Containership. The conclusion indicates that this method is feasible, especially the cross profile, the ship of designs and the matrix ship is very close, moreover uses biquadratic multinomial curves and the elliptic arc fitting section plane has many superiority, for instance use the multinomial and the elliptic arc equation can carry on the differential and the integral accurately, and it can calculate its geometry characteristic accurately; secondly, for multinomial coefficient's equation, the solution is quite convenient, therefore this method has certain project application significance.Finally, it is the conclusion and the prospect, which includes the good and bad points about the method used in this article as well as also questions waiting for solving.