Page 251 - Fluid Mechanics and Thermodynamics of Turbomachinery

232 Fluid Mechanics, Thermodynamics of Turbomachinery
and
2
T 02 /T 01 D [1 C U /.C p T 01 /].
2
Now
02 a 02 D 01 a 01 . 02 / 01 /.a 02 /a 01 /
1/2
D 01 a 01 [p 02 /p 01 .T 01 /T 02 / ],
therefore,

2
2
P m [1 C .
1/ i U /a ]
/.
1/ 2 .
C1//2.
1/
2 01
D 01 a 01 2 . (7.38)
A 2 [1 C .
1/ U /a 01 ] 1/2
C 1
2
In this analysis it should be noted that the diffuser process has been assumed to
be isentropic but the impeller has not. Eqn. (7.38) indicates that the choking mass
flow can be varied by changing the impeller rotational speed.
References

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