- 103 - 



could be secured. 



Figure V-10 compares the absolute pressure transducer signal 

 with that of the tank's resistance wave probe located about sixty 

 feet upstream of the DPG site. The resistance probe describes the 

 waves' non-linear profile featuring peaked crests and long shallow 

 troughs. Wave period is 5.0 seconds and the height is between 3.0 

 feet (0.925 m) and 3.36 feet (1.025 m) from crest to trough. The 

 absolute transducer also reports a period of 5.0 seconds and a wave 

 height of about 3.2 feet as calculated using stream function theory 

 (Dean, 197^). Stream function theory is used because of the great 

 non-linear appearance of the wave form. The calculated wave height 

 is only about 2.8 feet if linear theory is assumed. From Eq. 2.1, 



^ trougl 



amplitude "^^\ = — -t ^-^ C5 is) 



I trough I Y Kn [crest ] ^^-i-^J 



crest 1 _ l^foug'^J 



trough] 



Here, Y = 62.23 Ib/cu.ft. (13 C) , and Kp is approximately 0.87A and 

 1.068 for the wave crest and trough respectively from stream function 

 theory (Dean, 1974). This was calculated for a wave of five second 

 period in water depth 10.2 feet and absolute sensor height above the 

 bottom of 4.25 feet. The intimation of static water level is also 

 good. The no-wave tare value was steadily reported as 18.23 psia, 

 which corresponds to a water height above the sensor, from Eq. 4.35 

 of 5.91 feet. 



