Page 109 - 48Fundamentals of Compressible Fluid Mechanics

4.7. THE EFFECTS OF REAL GASES 71

e (4.134)
and for

The mass flow rate as function of the Mach number is

(4.135)

the mass flow rate is

For the case of
e

(4.136)

Example 4.7:
A design is required that at specific point the Mach number should be
3 ,
.
i. Calculate area ratio between the point and the throat.

, and temperature
ii. The stagnation pressure and the stagnation temperature.

the pressure
iii. Is the stagnation pressure and temperature at the entrance are different from
.
SOLUTION
the point? You can assume that
1. The solution is simplified by using Potto-GDC for
3 the results are

3

( (/3

2. The stagnation pressure is obtained from
'33

'33

3
The stagnation temperature is

%

(
%

3. Of course, the stagnation pressure is constant for isentropic flow.

(