Wave Analysis Techniques to Achieve Bow-Wave Reduction 



DISCUSSION 



Lawrence W. Ward 



Webb Institute of Naval Architecture 



Glen Cove, New York 



It is again a pleasure for me today to comment on a paper by a colleague 

 with whom I have had the opportunity this past academic year to carry on inter- 

 esting and valuable discussions and experimental investigations; this now, with 

 Dr. Eggers, completes a triumvirate at the Institut fur Schiffbau and at the 

 Hamburgische Schiffbau-Versuchsanstalt which, as the author mentioned, at- 

 tempted to bring both theoretical and experimental methods to bear during this 

 period on the question of which methods of wave analysis are both valid and 

 practical for determination of the wave resistance and other related questions, 

 such as that of the bulbous bow which the author has focused on in the paper. 

 Some of the results of this joint effort, in particular the results of a longitudinal 

 cut analysis of the wave elevation due to the model Inuid S-201, are given in 

 Table 4 in Part I. I would like to take this occasion to present other results we 

 obtained on the same model by the "X-Y" method, in order to draw a compari- 

 son, the first that has been possible using the same model under the same con- 

 ditions, between these two methods as well as with the author's previously ob- 

 tained results using the Eggers transverse-cut relationships. These results 

 are summarized in Fig. Dl, in which the wave resistance coefficient c^ is pre- 

 sented as a function of the Froude number F^ for the three test series. It is 

 seen that essential agreement is obtained between the three methods, except in 

 two regions, one in a hollow and the other at the highest Froude numbers 



Fig, Dl - Results of various wave 

 surveys on Inuid S-ZOl: L = 4.0 m 

 andC = R /(p/2)SV2 



to.30 



■v/gL 



767 



