Handbook of Turbomachinery Second Edition Revised - Ventech!

Figure 13 Arrangement of various turbine rotor/stator blade configurations: (a)
two-stage pressure-compounded impulse, and (b) two-stage reaction.
Consider the turbopump requirements for a portion of the SSME
liquid oxygen system. To support thrust chamber operation, the main pump
stage of the high-pressure oxidizer turbopump must maintain a discharge
pressure of approximately 4,000 psi at a flow rate of around 900 lb/sec. The
liquid oxygen tank pressure at the engine inlet is maintained in the vicinity
of 100 psi, with an excursion down to about 20 psi partway through the
powered flight. A single liquid oxygen pump capable of supporting inlet
pressures as low as 20 psi, and maintaining the needed discharge conditions
would result in a machine that is larger, heavier, and less efficient than the
engine requirements would allow. Further, it was found that if the LOX
pump inlet pressure could be raised to the vicinity of 300 psi, the turbopump
design could be optimized for a much more compact machine capable of
operating at a much higher speed. Although 300 psi was clearly unreasonable
for a propellant tank pressure, it was easily attainable with the use of a
small turbopump upstream of the main LOX pump to boost the propellant
Copyright © 2003 Marcel Dekker, Inc.