The simplified solution for a non-reflecting type barrier is the same. 

 Graphically these solutions are shown on Figure E-J4.. Now, x does not 

 appear directly in the solution in the form (E-2li.). As can be seen from 

 (E-2I1), only the regions of effect of the barrier are delineated without 

 refeipence to any coordinate system, 



W?ves Passing a Gap - Gap Width Less Than ^ Wave Lengths . - Blue has 

 shown that a simplified solution of the gap diffraction problem may be 

 found by adding together the separate solutions due to each arm of the 

 breakwater, and subtracting e~^^» In this manner we may graph the gap 

 solution as on Figure E-5, the factors in brackets indicating the effects 

 of the individual arms. This is the sinplified solution,.. The complete 

 solution contains additional terms coirputed from relationships similar to 

 those in equation (E-12), 



Calculations and Computations . - The computations for the gap problem 

 are somewhat more conplex than those for a single breakwater. If we 

 establish the following coordinate system, (Figure E-6) 



gap center line. 



Geometric 

 Shadow 



/)M/»/i>>//nf/)>fii/HM/7i 



origin of 

 coordinates 



Breakwater wing 



n 



Direction of incident 

 wave approoch 



FIGURE E-6 Diffraction coordinates at a breakwater gap 



E-8 



