Page 117 - Aeronautical Engineer Data Book

Basic fluid mechanics 93

1 ∂
q =
R
2
R sin ∂
1 ∂
q =

R sin ∂R
Additional shock wave data is given in Appen­
dix 5. Figure 5.10(b) shows the practical effect
of shock waves as they form around a super­
sonic aircraft.

5.7.2 The pitot tube equation
An important criterion is the Rayleigh super­
sonic pitot tube equation (see Figure 5.11).
� + 1 M 2 � /( – 1)

p 02 2 1
Pressure ratio: =
p 1

M p u p 2 2 p 02
1
1 1
1
M 2

Fig. 5.11 Pitot tube relations
�
2
2 M – ( – 1)
1

+ 1
5.8 Axisymmetric flows
Axisymmetric potential flows occur when
bodies such as cones and spheres are aligned