A = 



^o'^^ (2tt 63/36 6)2.8 _ _ . 



-iT^ 0787 -^-^ ' 



(67) 



and therefore from equation (37) 



o 

 This gives a value of the particle Reynolds number 



(68) 



10 



-5 



(69) 



-5 2 

 where the kinematic viscosity has been assumed given by v = 10 ft /sec. 



This value is clearly much greater than the value of the critical 



Reynolds number, R^, which is of the order 100. Thus, the value of f 



determined by equation (66) holds for the prototype condition and the 



necessary parameters for use in conjunction with Figures 2 and 3 may 



be determined for the prototype 



nk Ji = 0.47 

 o 



S^ = 0.935 



f/S. = 2.8/0.935 = 3.0 



> Prototype 



(70) 



and Figures 2 and 3 yield for the prototype: 



Transmission coefficient = T = 0.22 

 Reflection coefficient = R = 0.71 . 



(71) 



For the Froude model one may as a first approximation adopt the 

 assumption that Rj >> R^, in which case the estimate of f obtained for 

 the prototype still holds, i.e., f = 2.8 is a first estimate. To 

 evaluate the value of the particle Reynolds number, R^^, the procedure 

 is as previously outlined and from the well-known scaling of Reynolds 

 numbers in a Froude model, 



(Reynolds number scale) = (length scale) 



3/2 



(72) 



44 



