Hydrofoils Running Near a Free Surface 175 
8 
re Fey 1. (x)= —0,0526 x (plate - profile) | 
2.f (x)= —Q05%x-007%5 x? (circlesegment-profile) 
ee | | : 
x geom =+3 
1 2 3 4 
Fig. 25. Decrease of lift near the surface without regard 
to the apparent camber reduction 
rs Ag 9(™) 
C,(h") ae: Sg) RIA ne re (13) 
Cel aes 
C.(o) De 
The lift of the upper side can be written 
C,(h") = C,H) + C, (A) 
* Ago(™) ~ 
= DTT, aac ic “h Biga + aig(h ) 
h* * * 
+ o (4) [20 1(h ) + a, Ch }} (14) 
C,(h") 1 a, (0) 
L Bee ce ele =e Od eee * wh 00 * 
C,(@) re 0,5 anata) + alge) {oat ) amt Ay9(h") 
+ (2) [ 20168") + 20") 
where o(k*/2) stands the apparent camber reduction. The total lift of the profile then 
amounts to 
