Vassilopoulos and Mandel 



The results of the first phase of the correlation are reported herein in the 

 form of graphs of non-dimensional motion amplitudes versus wave length to ship 

 length ratio for constant Froude number (Figs. 2-57). Heave is divided by the 

 wave amplitude h^ and is considered positive upwards; pitch in radian measure 

 is divided by the maximum wave slope (2TT/k)h^ and is defined positive when the 

 bow is up. Amplitudes of motions are considered positive for both ahead and 

 astern wavelengths. Phase angles are superimposed on the same graphs and 

 are defined as lags when referred to the maximum wave elevation amidships; 

 their range is restricted to ±0-180° only. 



The second phase of the correlation was concerned with the effect of longi- 

 tudinal weight distribution on ship motions. The experimental data required in 

 this case were obtained from Figs. 16 and 17 of Ref, [19]. In the latter work, 

 Model C of Fig. 1 was ballasted in four additional ways so as to yield non- 

 dimensional radii of gyration of k^ = 0.21, 0.225, 0.255 and 0.270. The previ- 

 ous discussion with regard to presentation of data applies also in this phase of 

 the investigation with the following exceptions due to insufficient model data: 



a. Only amplitudes of pitch and heave were compared. 



b. Only directly ahead seas (y = 180°) were considered. 



c. The results are given for only three Froude numbers of 0.15, 0.20, and 

 0.25. 



Since Figs. 2-57 all pertain to the case of k^ = 0.24, Figs. 58-65 deal with the 

 remaining four values of k^ only. 



Wherever the wavelengths for resonance came within the range of values 

 shown on Figs. 2-65, arrows are drawn to indicate their critical values. 



KEYS TO FIGURES 2-65 



258 



