TABLE 1 — MODEL CHARACTERISTICS AND WAVE 
CONDITIONS FOR COMPUTATIONS 
(Model Length = 114.3 cm (3.75 ft); L/b = 5; Ca = 0.608) 
CONFIGURATIONS 
B LCG Radius of 
SYMBOL Gyration V/V L 
40 
20 
20 
10 
30 
WAVE CONDITIONS FOR CONFIGURATION —-— 
ee | eee 
Corresponding time histories of bow and CG accelerations are shown in Figure 5. The 
bow acceleration was computed at Station 0. As can be seen in these plots, the impact 
accelerations ranged in magnitude from cycle to cycle. The maximum impact (or negative 
value) acceleration computed during the final 2 seconds of run was used in the comparisons 
with experimental values. In some instances, particularly near resonance, the maximum 
impact acceleration was more than twice the average impact value. 
Figure 6 shows a comparison of variation of computed and experimental pitch and heave 
motion with wave height for the 20-degree deadrise model in a 15-foot wavelength and for a 
speed-to-length ratio of 6.0. Figure 7 shows the corresponding impact acceleration at the 
bow and CG. The computed results closely follow the experimental data, except for CG 
acceleration at the extreme wave height condition, where the computed value is apparently 
much lower. Experimental data show that the model was leaving the water at this wave- 
height condition. The computer model did not leave the water but came very close; 
11 
