176 S. Schuster and H. Schwanecke 
C,(h*) = C Ch) 
tuGaG@he) 
us 
4s 
2n | 00th" tae ig (2a) o (A fag (A) - acs yf (15) 
* 
* * h * *x 
Cain ye Agg(h’) + a, (A) + o() [ay Ch ) + a,(h )] 
C1 (©) Ayo(®) + 4,,(©) 
where 
= 01 ED pti sien 
411 (@) = 2m = -f 
In Eq. (15) only the factor o(h*/2) is unknown. It can be calculated theoretically, but then 
separate mathematical operations will be necessary. By experiment this camber reduction 
factor can be found easily from the reduction of the no-lift angle occurring in an approach to 
the surface 
pe MLD age nat 
se Deere as (0) ~ m() 
(16) 
where independence of the shape of the profile can be supposed. Figure (26) shows the fac- 
tor o(h) as found by experiments. With the aid of this factor the lift reduction of the profile 
can be found as a function of the depth h from Eq. (15) as shown in Fig. 27. 
Figure (28) shows the calculated lift of the upper side and of the lower side of the con- 
sidered profile dependent on the depth h, as well as the corresponding values taken by meas- 
urement. The actual increase of lift of the lower side and the decrease of lift of the upper 
05 20 
Fig. 26. Apparent camber reduction of a circle segment profile 
as found experimentally 
