Floating Body in iTregulav Waves 



TABLE II 



is 



The reflection force on the fixed vessel in regular beam waves 



Fy = iPga^Lv 



where -y ^-s a coefficient depending on the beam- wave length ratio. 

 For the wave lengths under consideration (\/B ~ 5) the mean value 

 of "Y is obtained from experimental data on Series 60 models is 

 about 0,5, This value increases up to one for shorter waves and 

 decreases for longer wave lengths. 



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

 irregular beam seas becomes 



(Tp = YPgo"^ L 



Py ^^^ Ediff 



and the r.m.s, value of the low- frequency sway motion is 



"Fy 



The sway damping is again obtained from an extinction curve. The 

 numerical value is ByCOgy = 4 ton/m. The results compared with 

 experimental results are shown In Table III. 



TABLE III 



977 



