Murthy 



NOMENCLATURE 



ACV air cushion vehicle. 



EFS external free -surface - free surface of water of infinite 



extent outside the immersed part of the side hulls and the 

 vertical projection of the flexible extensions at the front 

 and rear of the air cushion. 



IFS internal free surface - free surface of water contained 



between the inner sides of the immersed part of the side 

 hulls and the vertical projection of the flexible extensions 

 at the front and rear of the air cushion. 



A total waterplane area of the two side hulls at zero speed 



ahead. 



a amplitude of the regular incident waves. 



b one half of the separation between the two side hulls. 



F external force vector acting at the C. G. of the ACV. 



F pressure force vector. 



F pressure force vector (cushion hull). 



C 

 F pressure force vector (side hulls). 



H 



— ♦ 



F rigid body force vector. 



R 



F side force on an amphibious ACV in drifting motion, 



o 



f pitch stiffness function of the air cushion. 



f heave stiffness function of the air cushion. 



G steady Green's function. 



G unsteady Green's function. 



G equilibrium position of C. G. during steady translation. 



G' instantaneous position of C. G. during oscillations. 



g acceleration due to gravity. 



H hull function in (x, y, z) system. 



h total width of side hulls at (x', z 1 ) 



h , h hull function in (x'.y'.z 1 ) system on the starboard/port 

 side of S and port/starboard side of S_ . 



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