Wavemaking Resistanoe of Ships with Transom Stern 



^s Wave height due to transom stern sink 



0" Source strength for ship hull 



(r|,(r2 Source strength given by Eqs. (11) and (12), respectively 



(Tfj Source strength for bow bulb 



(Tg Source strength for transom stern 



p Density of water 



■y Quantity given by Eq» (5) 



DISCUSSION 



Georg P. Weinblum 



Institut fur Sahiffbau 

 Hamburg ^ Germany 



Some general remarks may be permitted, especially from 

 the point of view of application. 



So far investigations of more practical character deed pre- 

 ferably with the bow wave formations, while linearized wave re- 

 sistance theory treats with equal love the forebody and the afterbody 

 of displacement ships. Few experiments only have been conducted 

 to check, ceteris paribus, the advantage of form symmetry with 

 respect to the midship section in real fluid. Such tests have been 

 performed by the present writer with bulbous forms by comparing 

 simplified ship hulls: 



a) without a bulb (naked hull) , 



b) a bulbous bow only, 



c) a stern bow only, 



d) bulbs symmetrically arranged at bow and stern. 



These experiments are useful in the present context, starting 

 from the author's and my personal viewpoint, that in ideal fluid a 

 similarity can be reached in wave effects due to a transom stern and 

 a bulbous bow (because of a similarity in form representation by 

 dipole arrangements). The sketch annexed shows an impressive 

 improvement by the symmetrical bulbous ship design (d) , and this 

 indicates , that the combination bulbous bow + transom stern should 

 be useful as shown theoretically by the author. 



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