0.5 



I I I mi l l — I I 1 1 ii i ii — I I I mill — I I I mill r-n 



Interpolated 



Extrapolated 



— — Smoott) 



— — — Lower Limit of Rough 

 Turbulent Regime 



I I I I mil Ml r I I [ mil i i r r mil i i i i iiri 



10' 10* 10° lO' 



Reynolds No. (Rg) 



Figure 2. Friction factor diagrams (after Kamphuis, 1975). 



floor, R , and the relative roughness height, A/k , are known. The 

 Reynolds number is related to the bottom velocity under the wave by 



R = 



(4) 



where 



u. = maximum horizontal water particle bottom velocity is 



^ «sl 



T sinh 



2TTd 



L = wavelength 



.-7 



V = kinematic viscosity of seawater equals 6.25 x 10 meters per 

 second 



A = horizontal displacement amplitude of water particles is 



H, 



^sl 



2 sinh 



2Trd 



) 



k = wave number (2'Tr/L) 

 T = wave period 



