Norrbin 



Tests at FnL = 078 - 106 



Fig. 3 2. 98 000 tdw tanker - Moment coefficient N"(r')/u". 

 in deep and shallow water. 



XII. RESULTS FOR CONFINEMENT DERIVATIVES 



Figs. 33 - 38 present available empirical or semi-empirical 

 results for the main lateral hydrodynamic derivatives appearing in 

 the confinement terms of the completed mathematical model. The 

 derivatives Ygv-n and Nyy« for the 98 000 tdw tanker have been 

 derived from the near-to-wall tests in deep water, and are not shown 

 here. (Cf. Fig. 23.) 



In Fig, 33 the shallow water results obtained for the SSPA 

 tanker are compared with the experimental results published by 

 Fujino [5] , and with calculations from Newman's theory, [93] . The 

 SSPA analysis is based on a linear dependence of the derivatives on 

 I, and the results are given by plots on straight lines, also sug- 

 gested by the theory. Fujino 's derivatives are evaluated separately 

 for each depth. In gene red the theory seems to underestimate the 

 influence of finite depth, especially for the stiffness moment. 



Increase of added mass and added moment of inertia as 

 obtained from Fujino 's experiments and Newman's theory is shown 

 in Fig. 34, again in poor agreement. 



886 



