Linearized Potential Flow Theory for ACVs in a Seaway 



S, , S-. starbord/port side of S, , S_ 

 _ 1 o± 2 o± 1 o 2 o 



steady positions of S. , S below the load waterplane 



z'=0 ° ° 



strip of the longitudinal planes between z' = and z = 0'. 



strip of the longitudinal planes between z = and z =f 



coupled stiffness function = f, + f z. , 



r I x klm 2 X klm 



forward thrust of. ACV propulsion system. 



time 



absolute velocity of element of mass of ACV 



mean forward speed of ACV. 



rectangular co-ordinate system fixed in space. 



components of force vector. 



X , Y , Z components of pressure for e vector. 



■^d ' "^d ' ^d components of pressure force vector (cushion hull), 



c p c c 



X , Y , Z components of pressure force vector (side hulls). 



X i Y , Z components of rigid body force vector. 



R R R 



x,y, z rectangular co-ordinate system translating in space with 



uniform velocity V . 



x',y', z' rectangular co-ordinate system fixed in the ACV. 



x surge displacement. 



z heave displacement. 



x. x-coordinate of C. G. of waterplane area of the side hulls. 



A r 



x , z x, z-coordinates of the centre of buoyancy of the side hulls. 



B B 



x x-coordinate of the centre of pressure of the air cushion. 



P 



a motion perturbation parameter denoting the small order of 



the amplitude of the motions due to forced oscillation or 

 due to wave excitation. 



/3 cushion pressure perturbation parameter denoting the 



small order of the cushion pressure. 



7 the phase angle of the incident waves. 



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