calculating a wave Reynolds number. Furthermore, since the flow near the 

 Stillwater level contributes most to the moment around the mudline, the 

 location at which ^ax ^^ determined is chosen to be z = 0. Thus, 

 wave Reynolds number is 



u D 



max 



Rg = . (7-39) 



where v = kinematic viscosity of the fluid (v « 1.0 x 10"^ for salt 

 water), u^^^a; ~ maximum horizontal velocity at z = 0, determined from 

 Airy theory, is given by 



ttH 



L„ 



max -p T 



(7-40) 

 'A 



The ratio L^/L^ can be obtained from Figure 7-40. 



An additional parameter, the importance of which was cited by 

 Keulegan and Carpenter (1956), is the ratio of the amplitude of particle 

 motion to pile diameter. Using Airy theory, this ratio A/D can be 

 related to a period parameter = (u „ T)/D (introduced by Keulegan 

 and Carpenter) by. 



D ~ 27r 

 When z = Equation 7-41 gives 



(7-41) 



HI H Lo , ... 



A = ^— — , = . (7-42) 



2 tanhp^yj ^ ^^ 

 The ratio L,/L is from Figure 7-40. 



In a recent laboratory study by Thirriot, et al. (1971), it was 

 found that for 



- > 10 , Cq =* Cq (steady flow) ; 



1 < - < 10 , C^ > Cq (steady flow) . 



Combining this with Equation 7-42, the steady state value of Cj^ should 

 apply to oscillatory motion, provided 



A H L^ ^ 



- = > 10 , (7-43) 



D 2D L. 



7-104 



