Testing Ship Models in Transient Waves 



Test Series 1 



The first transient tests were conducted in December 1962 using Model 

 4941, a 13-ft model of a C4-S-A3 Mariner hull which had been previously tested 

 in regular waves. Pitch and heave in ahead waves were measured as well as 

 wave height with a sonic wave probe mounted approximately 12 ft abeam of the 

 center of gravity of the model. 



The philosophy of wave generation during this series of tests was to create 

 a wave which would contract and "peak," as described in an earlier section, at 

 a point somewhere near the model. Figure 6 shows the records taken during a 



WAVE HEIGHT 



PITCH 



A 



Recorded Transient 



PITCH 



HEAVE 



Amplitude and 

 Phase of Computer 

 Output Proportional 

 to Fourier Transform 

 of Input at f «= 1/T 



vAA/vAAAAAAAAAAAAAAAAAAAAAAAfVVVVVVVVAA — 



Analog Computer Output 



Fig. 6 - Measured transients for Model 

 4949 and typical analog computer fre- 

 quency response measurement 



517 



