Mori, j Inui and Kajitani 



Figures 34 through 36 show the calculated results, i. e. 

 (a) hull-generating source, (b) load water line, (c) amplitude func- 

 tion, respectively. 



The towing tests of M 21-M were run on May 9th through 

 12th, 1972 and Figure 37 shows its result. As far as wave resist- 

 ance is concerned, the agreement between experiment and the pre- 

 sent theory is noticeable. Moreover, M 21-M is much less, as ex- 

 pected, than M 21 in wave -making resistance at the designed Froude 

 number. 



These results may suggest that the principal leading fac- 

 tors of the 'sheltering effect are B/L and the shape of water plane 

 as discussed in the preceding sections. In this connection, it must 

 also be remembered that the simple n -correction of Equation (14) 

 was originally proposed not with Inuid models but with Pienoid models. 



Therefore, the correction function a ( £ ) which is obtain- 

 ed with M 21(B/L = 0. 1184) will be applicable not only to Inuids but 

 also to more general hull forms with flat bottoms. 



VIII. CONCLUSIONS 



Analytical method for obtaining the effective wave -making 

 source of a ship is developed, where the measurement of the hull- 

 side wave profiles is adopted as input data, instead of the free wave 

 patterns in the rear of a ship. 



Two Inuid models with different beam-length ratio (B/L = 

 0.0746, 0. 1184) are wave-analyzed . 



Clear discrepancy is observed between the two kinds of 

 sources, i. e. (a) hull -gene rating source m( £ ) based upon double- 

 model assumption, and (b) effective wave -making source m( £ ) 

 analyzed from measured wave profiles by means of the proposed me- 

 thod. 



The correction function a ( £ ) = m( £ )/m( £ ) which is ob- 

 tained from the wide model (B/L = 0. 1184) is almost identical with 

 the authors' proposal for the sheltering effect (1968), 



a( n = 1 - M (l- III ) , ( M = 0.4) 



704 



