Page 145 - Aerodynamics for Engineering Students
P. 145
128 Aerodynamics for Engineering Students
Doublet
axis
Fig. 3.20 Streamlines due to a doublet
- -
2c
-x-
Fig. 3.21
Consider again a source and sink set a very small distance, 2c, apart (Fig. 3.21).
Then*
rn rl rn r2
= - In - - - In -
’ 2n ro 27r ro
where f is the strength of the source and sink respectively. Then
rn
rnrlrn6
C$ = - In - = - In -
2n 12 4n
* Here TO is the radius of the equipotential q5 = 0 for the isolated source and the isolated sink, but not for
the combination.
