Table 8-12. Deepwater Wave Statistics (summary of data in Table 8-4), 



2. Calculation of Average F (a ). 



Equations (4-54) and (4-55) will be used to calculate the potential 

 longshore sand transport rates. Since the wave angle a in both equations 

 represents a 30-degree sector of wave directions, equation (4-55) is averaged 

 over the 30-degree range for more accurate representation; i.e., 



[a ] 



Aa J 



(cos a J sin 2a da 



= ± 



8 



9(Aa) 



\ 



cos a. 



i9/4 



- cos 



("ij 



9/4 



where Aa = a„ - a. = 11/6 



and the 



or 



sign is determined by the 



direction of transport. Special care should be exercised when < a < 15 

 and 75° < a < 90° . Further discussion on the method of averaging is given in 

 Chapter 4, Section V,3,d. The results of calculation are shown in the 

 following tablulation and also in Figure 8-32. 



8-87 



