E exciting function, e.g., E z = £33, £> — £«» 



F Froude number 



G coupling coefficient in eq. [7] 



H draft 



I area moment of inertia 



J mass moment of inertia 



K inertia coefficients 



K z function in eq. [3b] 



L length 



M moment 



N damping coefficient, e.f., N z = N 33 , Aty = N K 



N (£) damping coefficient per unit length. 



tt > / diffractional damping per unit length 



ir diffractional damping coefficient 



T natural period, T* = TVg/L 



U uniform speed of advance; 



x } 



Y > forces 



z ) 



V volume 



c wave phase velocity; restoring coefficient in eq. [6] 



f freeboard 



g gravity acceleration; coupling coefficient in eq. [6 J 



h wave height 



i V^l 



m mass; m^ — inertia values; m z = m 33 ; J 77 = m 55 



r wave surface elevation; r m wave amplitude 



t time 



\ 



x 



y \ coordinates, y* =-- y/L 



z ) 



z m heaving amplitude, z m * = z m /r„ 



a waterline area coefficient 



P midship section coefficient 



irL, tt 



7 



\ X* 

 S block coefficient 



e phase angle 



G angle of yaw 



k dimensionless damping coefficient 



\ wave length, X* = X/L 



/1 resonance factor, amplification factor 



v natural frequency *>* = vVL/g 



p density 



97 



