(searched for: doi:10.1299/jsmeb.49.806)
Published: 18 January 2021
Journal of Engineering for Gas Turbines and Power, Volume 143; https://doi.org/10.1115/1.4049015
Cavitation dynamics continue to pose a significant risk in the development and operation of launch vehicle (LV) propulsion systems. In addition to generating unsteady loads that can directly damage turbopump hardware, cavitation dynamics often couple with LV fluid feed systems, producing system wide POGO instability that can cause catastrophic failures. Despite its importance, the current understanding of cavitation dynamics, and especially pump transfer matrices, is limited. Given the relatively sparse amount of inducer transfer matrix data available, there is a critical need for more in-depth characterization of the cavitation dynamics in turbopump inducers to avoid POGO instability. This paper defines and validates a new reduced-order approach to infer key parameters such as cavitation compliance, K, and mass flow gain factor, M, from simple, single sensor unsteady pressure measurements during inducer inlet pressure ramps. The utility of this approach is demonstrated for a range of inducer geometries reported in the literature. The results are in agreement with experimental data and the paper provides a new capability supporting the assessment of LV POGO instability.
Published: 18 March 2017
Topology Optimization in Structural and Continuum Mechanics, Volume 575, pp 65-86; https://doi.org/10.1007/978-3-319-49719-8_3
The article reviews the main forms of flow-induced instabilities detected in the liquid propellant turbopumps systems of modern rocket engines, with special reference to rotating stall, rotating cavitation, cavitation surge and higher order surge modes, illustrating their characteristics, origin and damage potential.
Acta Astronautica, Volume 132, pp 19-24; https://doi.org/10.1016/j.actaastro.2016.12.007
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Journal of Fluids Engineering, Volume 133; https://doi.org/10.1115/1.4005257
The paper shows the results of an experimental campaign conducted in the CPRTF (Cavitating Pump Rotordynamic Test Facility) at ALTA S.p.A., aimed at characterizing the cavitation thermal effects on two tapered-hub, variable-pitch inducers, designated as DAPAMITO. The semiempirical method proposed by Ruggeri and Moore for scaling the thermal cavitation effects has been successfully applied and consequently, a further validation of this method has been provided. The influence of the temperature on the intensity of the performance degradation associated with the attached cavitation instability has been identified as a new typology of cavitation thermal effects. In this case, the inhibition of the bubble growth due to thermal effects can be detected by the reduction of the performance degradation usually associated with this type of instability.