ELEVATION, z (cm) 



20 40 60 



FLOW SPEED, V (cm/s) 



V(mid) ■ 22 cm/s 

 V(mld) ■ 59 cm/s 



V(mid) ■ 43 cm/s 

 V(mid) ■ 74 cm/s 



Figure 14. Vertical distributions of flow speed 



If vertical profiles of flow speed are plotted on semilog paper, those 

 following the logarithmic law will appear as straight lines, with the slope of 

 the line equal to U* and the y-axis intercept equal to z . Table 1 

 presents U* (cm/sec), z (cm), and squared correlation coefficient r 2 

 calculated for the profile data using the logarithmic law as a function of 

 midflow speed V mid . The flow speed profiles followed a logarithmic profile 

 well, with squared correlation coefficients ranging from 0.96 to 0.*98. 

 Testing procedure 



40. Most nozzles were tested both at middepth, for which the flow speed 

 was determined to be fairly uniform over the region occupied by the nozzle, 

 and on the tank bottom (resting on the carpet) where the flow increased from 

 the bed in a logarithmic manner. Three consecutive readings from the flow 

 meter were taken at each point to ensure that flow conditions in the tank were 

 stationary and then averaged. 



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