This paper presents a brief overview of the pogo phenomenon in liquid propellant launch vehicles and reviews the dynamics of cavitating pumps. The importance of the cavitation compliance and mass flow gain factor in determining the dynamic characteristics and instabilities of rocket engine turbopumps is also discussed. A collection of the nondimensionalized pump inlet compliance data is plotted together on a single graph with the purpose of identifying trends and correlations between cavitation compliance and cavitation number. An initial assessment of the data demonstrated two trends, which separated the single term compliance data from the two term compliance data. The two term compliance data is suggested to be three to ten times smaller than the single term compliance data. However, by combining the nondimensionalized compliance together with the nondimensionalized mass flow gain factor to form a single compliance model, it is demonstrated that all of the data can be correlated together as a function of cavitation number. From this review, an initial estimate for pump cavitation compliance in new pump designs and pogo stability analyses can be obtained.
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