Page 297 - Aerodynamics for Engineering Students

Compressible flow 279

10.0 - 160
-
9.0 I50
-
8.0 140
7.0 - 130
6.0 - 120

A/A* 5.0- 110
4.0 - 100
3.0 - 90

80 PdP
70
6.0 60
50
40
Po/P 3.0 30
20
In I
IO
I."
I I I I I I 1 I I I I I I I I I
0 0.2 0.6 1.0 1.4 1.8 2.2 2.6 3.0 3.4 3.8
Mach number

Fig. 6.2

Note that this is the minimum pressure ratio that will permit sonic flow. A greater
value is required to produce supersonic flow. The ratios of the other parameters
follow from Eqns (6.18) and (6.2):

(6.19)

(6.19a)

= 1.58 for airflow (6.19b)

and

(6.20)

TO
_- T-l+2 Y-lM2 (6.20a)

for airflow (6.20b)