1 1 o 



Therefore , 



(f j = 2 n C 

 and since from equations (2-3) and (2-6) 



= tanh 



'2Trd' 



and from equation (2-35) where 



n = — 

 2 



1 + 



4nd/L 



sinh(47rd/L) 



H 



1 



tanh(2TTd/L) 



(4iTd/L) 

 sinh(4TTd/L) 



1 + 



= K 



(2-44) 



where Kg or H/H^ is termed the shoaling aoeffioient. Values of H/H^ 

 as a function of d/L^ and d/L have been tabulated in Tables C-1 and C-2 

 of Appendix C. 



(b) For the given wave, d/L^ = 3/156 = 0.01923. From Table C-1 or from an 

 evaluation of equation (2-44) above, 



Therefore, 



H 



W 

 o 



1.237 



H = 1.237(2) = 2.474 m (8.117 ft) 



(c) The rate at which energy is being transported toward shore is the wave 

 energy flux. 



P = — E C = nEC 

 2 o o 



Since it is easier to evaluate the energy flux in deep water, the left side 

 of the above equation will be used. 



- 1 - 

 P = - E C = - 

 2 o o 2 



1 ^^^V" ''-' 1 10.050(2)2 



15.6 



P = 39,195 N-m/s per m of wave crest 



881 1 



P = = 16.02 hp/ft of wave crest 



550 



2-28 



