WAVE 

 HEIGHT 

 PROBE 



FILTER 



i t PULSED ULTRASONIC 

 I SIGNALS 



WATER SURFACE 



SERVO 



CONTROL 



UNIT 



e 



s 



SERVO 

 AMPLIFIER 



- 



SERVO 

 VALVE 











1 1 



e 

 1 . p 



HYDRAULIC 

 POWER 

 SUPPLY 



HYDRAULIC 

 CYLINDER 









* FEEDBACK 





HYDRAULIC CYLINDER 





TRANSDUCER 



Figure 4 



POSITION FEEDBACK 



Block Diagram of SERVOMECHANISM for Pitching Model at 



Specified Phase Relative to Waves 



80 1 1 1 1 1 1 1 1 



MEAN VALUE •§; 



MEAN VALUE ±1.96 STANDARD •f, 



DEVIATIONS (AT A GIVEN POSITION 'fl 



ANGLE, STATISTICALLY. 95 PERCENT •?;.. 



OF THE MEASURED POINTS LIE IN THE °'!H|it''" 



BAND BETWEEN THE 2 X-SYMBOLSl 



45 



90 135 180 225 270 315 360 

 POSITION ANGLE d (DEG) 



Figure 5 - Experimental Data Showing Plus and Minus 1.96 

 Standard Deviations on Measured Values of F^ 



WITHOUT DYNAMOMETER BOAT 



WITH DYNAMOMETER BOAT 



r/R=0.63 



45 90 135 180 225 270 315 360 

 WAKE POSITION ANGLE 9^ (DEG) 



Figure 6a - r/R ^ 0.63 



1.2 



1.0 



^ 0.8 



> 



0.4 



0.6 



0.2 



21 



> 



-0.2 



0.2 



?° 



wr: 



WITHOUT DYNAMOMETER BOAT 



— WITH DYNAMOMETER BOAT 

 _ r/R=0.96 



45 90 135 180 225 270 315 360 

 WAKE POSITION ANGLE 6^ (DEG) 



Figure 6b - r/R = 0.96 



Figure 6 - Distribution of Wake in Propeller Plane 



37 



