Hydrofoil Motions in a Random Seaway 

 ;; Pitching moment 



"'' '' — ^^7^^ 



(60) 



^' - Yawing moment 

 izz^- izx'^ = 1 „ 2^ ■ (61) 



Velocities Along Space Axes 



X = (1 + u) COS - V sin (62) 



Yg = (1 + u) sin + V cos ' (63) 



Zg = - (1 + u)^ + w . (64) 



Equations (56) to (61) are required for the six degrees of freedom of the 

 craft. Equations (62) to (64) are the relations between craft and space axes and 

 are required for relating sea motion to craft motion. 



Hydrofoil Equations 

 Basic Equations 



Heave 



Surge 



Pitch 



Sideforce 



Roll 



Yaw 



2m[w - ^(1 + u)] = -Cl - Cl (65) 



2/xG + oc^ = Cj - [Cj3 + Co ] (66) 



o 



2m[v + 0(1 + u)] = Cy + Cl (68) 



ixx<^= Cl + ixz^+ Ciyy-izz)^>A 



(69) 



i, 0=C +i cb + ( i -i )$)(9. (70) 



zz" n xz^ v-^xx yy' ^ ^ 



221-249 O - 66 - 41 625 



