904 oC 
where 
~ 
i} 
= a resistance coefficient, 
<I 
' 
= mean velocity of flow. 
The following empirical expression for A has been given by 
Blasius (see, for example, reference 15). 
(12,3) A = .3(R)7°25 
iat Vv = 107 em/sec, R= 10° 
s = 1 cn, Ax 9.48 x 1075 
D= 1 cn, 
Then “ & .5 atmospheres. 
The Bernoulli Effect 
iS. The equatione of continuity and motion are 
(13.2) dur (pt) + S£20 
(13,2) ~ grok p = 
It has been shown that the incomnressive approximation introduces 
negligitle error in the descrivtion of a single piston. Hence, 
sesume that the fluid is incompressible. Then, if YW is the 
velocity potential, equations (13.1) and (13,2) become 
(13.3) EN Dee 
(13,4) RiGee: 
respectively, where ae indicates differentiation along a stream- 
oS 
