Page 183 - 48Fundamentals of Compressible Fluid Mechanics

9.4. THE WORKING EQUATIONS 145
Fanno Flow
* * *
P/P , r/r and T/T as a function of M
1e+02 4fL
¾¾
D
P
¾¾ *
P
1e+01 *
T /T
0 0
*
P /P
0 0
U/U*
1

0.1

0.01
0.1 1 10
Mach number
Fri Sep 24 13:42:37 2004
Fig. 9.2: Various parameters in Fanno flow as a function of Mach number

The results of these equations are plotted in figure 9.2 The fanno flow is in many
discussion about Reynolds
number and dimensionless
friction parameter. cases shockless and therefore a relationship between two points should be de-
rived. In most of the times, the “star” values are imaginary values that represent
the value at choking. The real ratio can be obtained by ratio of two star ratios as
an example

(9.48)

A special interest is the equation for the dimensionless friction as following

(9.49)

Hence,
(9.50)

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