Joosen 



with 



N3 = ^L ' N4 = -VS(ST+l)(l-r) sgn(^-^i) - ^CSr+2y+l) , § = 47-!. (4.9) 



For ^L = these formulae become: 



which is in agreement with (4.1). 

 For yflp = the result is: 



G4 = 0, G3 = T.^L {-Ho(^J^i-^l) - YoC^J^i-^l) + 2i Jo(^Lki-^l)} • 



This has been obtained already in the papers [1], [2], [5]. 



THE ADDED MASS AND DAMPING COEFFICIENT 



The varying part of the pressure exerted by the water on the body equals: 



p(x,y,z,t) = — gLpi . 



y 7;: 





(5.1) 



Considering only the heaving motion the vertical force acting on the ship be- 

 comes: 



-1 c(^) I 



,77, O - i — ^2f(^'^'^H d"? 



= "Iz^O + "z^O ' 



(5.2) 



where 



8m, 





4^2 Hj e4 



are the coefficients for added mass and damping. 



For the case I these coefficients are already calculated for a family of 

 cross section curves, see [6], [7]. 



4) 



180 



