Future Space Transfer Vehicles (STV) will be required to perform missions (orbital transfer, Lunar/Mars transfer and descents) for which deep engine throttling is needed. In order to do this the turbopumps that propel the Space Transfer Vehicles need to be able to operate at different flow rates. The current state of the art cryogenic fuel and oxidizer turbopump designs do not operate well at off-design flow rates mainly due to stall and flow separation in the diffuser section. The purpose of this Thesis is to analyze the behavior of the fluid in the diffuser and the vaneless and vaned region of the MK49-F turbopump at different flow rates and to use fluid injection as a way to reduce the flow separation present in the vaned diffuser. To meet this objective a finite element based code, FIDAP, was used to build a three-dimensional model based on previous works done on the vaned diffuser. Previous works studied the behavior of the fluid in the vaned diffuser without taking into consideration the vaneless diffuser. From the results obtained, it was observed that flow separation has occurred at the bottom plane of the vaned diffuser, when the flow rate was reduced to 60% of the design flow, and in the top plane of the vaneless region. These results are different from the ones obtained in previous works where the flow separation was found in the top plane of the vaned diffuser. This shows that with the addition of the vaneless section, the flow behavior changes significantly. Fluid injection was applied at the bottom plane of the vaned diffuser through six different slits at 20% and 60% of the design flow. Various rates of fluid injection were tested for their effectiveness in suppressing or eliminating the flow separation. Results showed that at off-design flow conditions fluid injection is an effective way to eliminate separation.

Library of Congress Subject Headings

Turbine pumps--Dynamics; Space vehicles--Fuel systems; Fluid dynamics; Unsteady flow (Fluid dynamics); Turbulence

Publication Date


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Department, Program, or Center

Manufacturing and Mechanical Engineering Technology (CAST)


Ogut, A.

Advisor/Committee Member

Nye, A.

Advisor/Committee Member

Vendataraman, P.


Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: TJ267.5.D4 P388 1996


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