Definition and Validation of Cavitating Rocket Turbopump Transmission Matrices for Modular Multi Actuator Disk Approach

Abstract

Cavitation-induced instabilities are a critical issue to face in the design process of rocket turbopumps, and reduced-order linear methods still represent a powerful tool to evaluate their onset. The modular multi-actuator disk approach is a successful method developed to study the dynamic behavior of compressors. Recently, it has also been proposed for the assessment of the dynamics of cavitating turbopumps. In this paper, the modular multiactuator disk approach was used as the mathematical framework to implement and validate a well-established model of a cavitating inducer developed in the 90 s for the assessment of azimuthal instabilities with a particular focus on rotating cavitation. The matching between the obtained results and the available data in the open literature for a tapered inducer validated the dynamic model of the cavitating inducer implemented in the new mathematical framework. The flexibility introduced by the new modular approach represents a step toward the study of complex hydrodynamic systems that are not limited to the simplified configuration studied by the actuator disk model proposed in the 1990s.