Developments in Theory of Bulbous Ships 



0- 



Fig. 12 - Comparison of the first order wave and the total wave (a = 0.1 rad) 



We notice that when we cancel the regular wave by the bulb, the line integral due 

 to this wave will be also cancelled. 



This study of the line integral (50) has just started. However it seems to be 

 quite promising for furtherance of a proper understanding of ship waves and of 

 their reduction. 



CONCLUDING REMARKS 



Theory and experiment are always stimulating and helping each other. Al- 

 though this report is on the theoretical side, it does not mean that the influence 

 of experiments are underestimated. This report is merely intended to further 

 appreciation of our great predecessors, Michell, Havelock, Wigley, Weinblum 

 and Inui for the theories related to the bulbous bowed ship, and to add a slight 

 theoretical illumination to them. 



The mechanism of the bulb at the ship bow (or stern) is completely clari- 

 fied. The type of bulb for a given ship hull, and the size and the vertical area 

 distribution of bulb for a given Froude number are derived. The higher order 

 influence is known to be the major reason for the phase shift of the regular 



221-249 O - 66 - 71 



1093 



