Investigation of suction recirculation in rocket pump inducers

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Virginia Tech


Rocket pump inducers are studied with a Navier-Stokes solver, the Moore Elliptic Flow Program, MEFP. Two redesigns of the Rocketdyne ADP inducer are performed. The first redesign changes the hub-tip ratio from 0.3 to 0.4. The second redesign influences the leading edge tip region. This part of the blade is rounded off in a meridional view, resulting in an increased sweep angle over the outer 30 percent of the blade height.

Inlet recirculation and cavitation performance are the main concern of this thesis. The literature review focuses on these two areas and on previously performed inducer calculations.

The calculation grid of the original design was altered for the two redesigns using a C-program. Then the new designs were investigated at three different flow rates: 110%, 100%, and 89%. Computational results were available at the same flow rates for the original design.

The comparison of the results showed that the performed design changes did not significantly influence the recirculation performance. In fact for the redesign with the rounded-off leading edge the backflow increased. The cavitation performance showed some interesting changes. For both redesigns the minimum pressure was raised significantly. The case of the rounded-off leading edge showed an increase in minimum pressure at the leading edge and a decrease of minimum pressure over the rest of the leading edge height, thus resulting in probably better cavitation performance.

A theory was presented that gives a possible explanation for the occurrence of inlet recirculation. The calculation results for the design changes of the Rocketdyne inducer are consistent with the theory, but the theory does not correctly predict the different recirculation performance of an SEP inducer.



pumps, inducer, Computational fluid dynamics, recirculation, cavitation