Minimum Wave Resistance of Surface Pressure Distribution 



Dr. Bessho has clarified the conditions of minimum resistance for pressure 

 systems in a similar far-reaching manner, as he and Krein have succeeded in 

 doing it for the Michell ship — now a classical problem which caused so much 

 discussion. Obviously, further work should be done on nonrectangular domains 

 of pressure distributions and on combinations of such domains. Further, his 

 remarks on ship forms and singularity (source-line) distributions open the field 

 for a much needed treatment of the resistance of moderately fast and high-speed 

 forms, including fast displacement ships with transom sterns. 



I have two questions: Dr. Bessho's g equals my speed parameter 

 7q = 1/2F^. How is this g defined, and how is the condition obtained given by 

 Eq. (27)? 



REPLY TO DISCUSSION 



Masatoshi Bessho 



I thank Prof. Weinblum for his kind remarks and will clarify his questions. 

 The definition of g in my paper is as follows: Suppose the uniform velocity V is 

 unity and take the unit length to be a half of the ship length L; then the gravity 

 constant g in this unit system is 



where g* is the gravity constant in the usual unit system, so that it equals Prof. 

 Weinblum's y. In the latter part, the breadth of the planing surface is taken as 

 twice unity, so that 



^ " V2\2 



Equation (11) is derived as follows: We can introduce a regular function -n 

 such that 



^-(x,y,z)= -^|^+ g^)0(x,y,z) 

 having the surface value 



^(x.y,-0) = ^P(x,y) . 



On the other hand, if 4^ can be calculated from a regular function M by the 

 equation 



791 



