where ¥ = displaced volume 



p = density of water 



U = towing speed 



W = tank depth 



H = water depth 



m' = m'(F u ) = added mass in the longitudinal direction 

 H 



F R = U//gH 



In the derivation of Equation (8), it is assumed that the waterplane area 

 of the ship hull is so thin that a line integral term is neglected, and the 

 body boundary condition is satisfied exactly on the body surface. From 

 Equations (7) and (8) is obtained 



Au ¥ + m'/p , Q s 



TT = T (9) 



AL (1-F R ) 



where A = WH is the cross sectional area of the tank. It is of interest 

 to note that when the value of g approaches infinity, F approaches zero, 

 and Equation (9) reduces to the case of a wind tunnel, where 



Au = ¥ + m'/p (1Q) 



U AL 



It is also of interest to note that when the body boundary condition is 

 linearized, i.e., satisfied on the body centerplane, Equations (9) and (10) 

 further reduce to 



Au = 5 (9 ') 



TI 2 



U AL (1"F H Z ) 



in the presence of a free surface and 



