r==^^r- 



7 



/ 



14deg ~~^ 



[1 1 



/ 



'e 



^ 



^ / 



-00 



-co 



7 





-•-6m -*- 



tl.8m / 



CM 



c 





"Initial 



1 1 



Shoreline 



1 1 1 1 



"CJI 



c 



2 4 6 8 10 12 14 16 





X(m) 





Figure 16. Laboratory arrangement for Case 4 

 (Hanson and Kraus 1991) 



//„ = 5.8 cm, T= 1 .2 sec, and G = -14 deg. The obliquely breaking waves gene- 

 rated a longshore current and longshore sand transport on the mode! beach. 



Calibration 



GENESIS was calibrated to Case 1 of the physical model study. Cross-shore 

 profile adjustment is evident in the shoreline positions from the early portion of 

 the physical model simulation. For this reason, the shoreline measured after 

 elapsed time /■ = 1 hr was used as the initial shoreline for calibration. Calibration 

 resulted in model coefficients of A'/ = 0.3 and A^ = 0.15 (same values obtained by 

 Hanson and Kraus (1991)). Comparisons of the calibrated shorelines modeled by 

 GENESIS and measured in the physical model basin at / = 1 , 6, and 1 8 hr are 

 presented in Figure 17. The modeled and measured shorelines at elapsed time of 

 6 hr closely agree. The modeled shorelines at ? = 18 hr agree in trends with the 

 measured shorelines, but do not contain the smaller scale features evident in the 

 measured shoreline. These smaller scale features are likely created by basin 

 circulation and reflected wave patterns that are not represented in the numerical 

 model. 



IVIodeling T-hiead groins 



T-head groins are modeled in GENESIS by superimposing a detached break- 

 water on the tip of a diffracting groin. Using the same incident waves and cali- 

 bration coefficients from Case 1 . the T-head groin configuration was simulated. 

 The resulting shorelines compare favorably with those measured in the physical 



Chapter 3 Functional Design 



17 



