O U, u 



D V, V 



AC w, T. /) 

 -G B B- 



-B- 



A 



D 



A 



a 

 A 



-B- 



U 



A 



D 



A 

 a 

 A 



D 



A 



-B- 



A 



D 



A 



D 



A 



a 

 A 



D 



A 



-B- 



o A 



D 

 O A 



a 

 o A 



D 



O A 

 D 



O A 



e- 



• u 

 A w 

 O J, p 

 -ifii ^ 



• o • 

 A 



• o • 



A 



• o • 

 A 



• o • 

 A 



• o • 



Figure 2.3. Staggered numerical grid. 



32 



