to approjcimately 0.9 for tanB = 1/1.5 should be applied to the predicted 

 results. 



It is important to realize that the procedure is empirical and 

 therefore is limited by the range of the independent variables used in 

 the experiments establishing the procedure. These limitations of the 

 procedure are discussed in Section III. 4. a. 



Numerical Example . To illustrate the application of the procedure 

 for prediction of reflection coefficients for rough impermeable slopes 

 consider the following example specified in Table 4. 



Table 4. Information used in numerical sample calculations. 





Prototype 



Froude Model 

 length scale 1 :25 



Incident wave amplitude 



a. in feet 

 1 



1.75 



0.069 



Wave period 



T in seconds 



12.5 



2.5 



Water depth 



h in feet 

 o 



29.2 



1.167 



Incident wavelength^ 

 L in feet 



366.0 



14.56 



Slope angle 



tang (1 on 1.5) 



0.667 



0.667 



Surface stone size 



d =1/2 (d +d . ) in feet 

 max mm 



3.12 



0.125 



^L obtained from linear wave theory using h and T. 



Since a Froude model scales the slope frictional effects correctly 

 for fully rough turbulent flow conditions, either the prototype or the 

 model may be taken as the basis for the following numerical calculations, 

 Choosing the model it is seen from the information presented in Table 4 

 that 



76 



