Verhagen 



1.2 



CM. 0.8 

 E 



c 



•o 



UJ 



0.4 



O 



v,2 



Va/f *" 



Fig, 16. Relation between the low-frequency energy- 

 variation and wave characteristics 



when a Is the wave amplitude and sln^a Is the mean square of 

 the angle between the tangent at the ship's waterllne and the longi- 

 tudinal axis* 



Now the r,m,s, value of the low-frequency exciting force 

 becomes 



<rp^ =* Pio-fdiff B sin a 

 and the r.in,s, value of the low- frequency motion Is 



_ - "Fx 



ox 



The surge damping B,, Is obtained from an e xtinctio n curve, 

 numerical values are B^ • "ox" ^^^O ton/m, s In*^ a s 0.24» 

 results compared with the e3q)erlmental results are shown In Table 11. 

 The agreement Is good. 



The 

 The 



976 



