Analysis of Ship-Side Wave Profiles 



By summarizing the preceding discussions (VI. l) and (VI. 2) 

 it may be safely concluded that the real mechanism of the sheltering 

 effect a ( £ ) should be investigated not only by the second order con- 

 siderations but also from some different kind of approaches such as 

 suggested by Brard \_^\ or Pien and Chang \J>\ . 



VII. APPLICATION TO HULL FOR M DESIGN 



Although the theoretical basis of the sheltering effect still 

 remains unsolved, the presently obtained results will be of practical 

 use for the hull form design with least wave resistance. 



As an example, an asymmetry Inuid model M 21 -Modified 

 is designed under the same geometrical restraints as M 21 except 

 that 



(a) The approximate correction function a ( £ ) which is 

 given in Figure 18 is applied in the process of minimization of wave 

 resistance. 



For example, at the designed Froude number Fn = 0. 2887 

 (K Q L = 12), we have 



( 0. 3 + 0. 8 I £ I , fore body 

 «(*)'= (38) 



' 0. 7 + 0. 3 | £ | , aft body 



(b) The correction function a ( £ ) being asymmetry fore 

 and aft, the optimized hull form is also asymmetry under the follow- 

 ing restraint, 



/ 



Total source = W = / m( £ ) d£ =0 (39) 



(c) The modified Fourier expansions are used for m( £ ). 



It is expected that the modified asymmetry model M 21 -M 

 will be superior to the original model M 21 as far as wave resist- 

 ance at the designed Froude number is concerned. 



703 



