Table 9 

 Sand Fluxes in Center. Near, and Far Subbasin Sections of Tank 







Testing 









Sand Flux 









V mid 



Time 

 (min) 









g/cm 2 /min 









(cm/sec) 



Total 



Near 



Diff. 



Center 



Diff. 



Far 



Diff. 



58.0 



7.5 



1.49 



1.56 



0.07 



1.52 



0.03 



1.39 



-0.10 



59.8 



7.5 



1.93 



1.60 



-0.33 



1.99 



0.06 



2.19 



0.26 



60.0 



2.5 



1.36 



1.04 



-0.32 



1.39 



0.03 



1.63 



0.27 



66.1 



7.5 



4.19 



3.68 



-0.51 



4.54 



0.35 



4.28 



0.09 



68.7 



2.5 



4.42 



3.38 



-1.04 



5.28 



0.86 



4.44 



0.02 



69.2 



7.5 



4.98 



3.83 



-1.15 



5.75 



0.77 



5.23 



0.25 



Avg 









-0.55 





0.35 





0.13 



98. The modified basin flux for a 5-min test and equation-predicted 

 nozzle fluxes with the 95 percent confidence limits are presented in 

 Figure 35. 



Ambient Sand Transport Rate 



99. The curve labeled "5-min Basin" in Figure 35 represents the basin 

 transport fluxes to which the nozzle transport fluxes should, in principle, be 

 calibrated. However, although the C nozzle-predicted sand transport fluxes 

 are comparable to the basin transport fluxes at lower midflow speeds, as much 

 as 45 percent higher values of flux were obtained with the C nozzle at higher 

 speeds. There are at least five possible explanations for this discrepancy. 



a. The C nozzle produced an increased flow speed in its vicinity, 

 thereby collecting more sand than was actually being transported 

 (similar to the H-S sampler). 



b. The cloths used to collect sand in the basins were not sufficiently 

 secured and allowed material to be lost from adjacent sections of 

 cloth. 



c. Sand transport at the basins was less than transport in the 

 vicinity of the trap testing area. 



d. Greater flow speeds caused increased suspended sand transport, 

 which was not collected in the basins. 



70 



