(.2 



1.0 



0.8 

 S0.6 



0.4 























































t 

































































































































































</' 



































i. 











































































/ 































































0.2 



0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 

 hb 

 2 



Figure 42. Wave radiation functions 



(from Ippen and Goda, 1963) . 



************** EXAMPLE PROBLEM 20************** 



GIVEN : A fully open inlet has a width, B, given by B = 0.194 L^, where 

 Lj, is the length of the inlet. The incident wavelength L = 25B. 



FIND : The resonant amplification in the inlet. 



SOLUTION: 



kB _ 2ir(0.04L) 

 2 2L 



0.1257 



From Figure 42, where b = B for a fully open inlet 



ip. = 0.12 



and 



From equation (298), 



*, = 0.24 



a j [(cos kL, - ip 2 sin kL,) 2 + ip sin 2 kL,] 



1/2 



137 



