Means for Reducing Bypass Flow Requirements in Liquid Hydrogen and Liquid Oxygen Tank Mounted Boost Pumps on Centaur Vehicle

Cryogenic centrifugal pumps cannot be operated at extremely low flow rates without internal boiling of the fluid Hence bypassing part of,the flow becomes necessary. This paper presents an analysis for minimizing bypass flow on the Centaur boost pumps. Various effects are discussed in detail. The temperature-pressure relationships in the liquid hydrogen boost pump are evaluated in relation to bypass flow requirement to determine if this flow rate can be reduced or eliminated. The minimum quantity of flow without any bypass was analytically estimated, and it was observed that it compared closely with the test results.