Salinity affected settling velocity only slightly, the decrease in 

 settling velocity between fresh and 39 o/oo salinity water being only 

 about 5 percent. Difficulties in keeping the temperature constant in the 

 settling tube and difficulties in obtaining representative 10-gram splits 

 of the coarser grained samples for the WHRSA make the curves of Figure 6 

 accurate only to a first approximation. The curves are accurate enough, 

 however, for expressions requiring the use of settling velocity values 

 for aggregates of sand from the study area at Virginia Beach. 



Settling velocities (V p ) for the natural environment (Temp. = 6.9° C: 

 Salinity = 26.74 o/oo) on 25 March 1963 were used in the computations of 

 dynamic properties of the particles. 



The settling velocities of the corresponding nominal spheres (V n ) 

 were extracted from the nomogram in Rouse (1937). 



Determination of Reynolds Numbers and Drag Coefficients . Reynolds 

 numbers based on the mean size were computed for each sample using the 

 equation : 



P, d V 

 R =-^ E (18) 



where 



Pf = 1.0209 (from U. S. Navy H.O. Pub. No. 615) 



d n = M z in cm. 



V = Mean settling velocity (in cm/sec) under prevailing 

 conditions 



P- = 0.0151 poise (from Miyake and Koizumi, 1948) 



Drag coefficients corresponding to these R e values were extracted from 

 Table 1, modified from Schulz, et al. (1954). 



Reynolds numbers for the mean nominal spheres (R n ) corresponding to 

 each of the samples from the 3rd Street pier transect were computed (Table 

 4) using the following equation from Briggs, et al. (1962): 



R n = ^S (19) 



v 



Drag coefficients corresponding to these R n values were computed using 

 another equation from Briggs, et al. (1962): 



C D =(DSF) (C d ) (20) 



