ISBN 9783843943222

978-3-8439-4322-2, Reihe Ingenieurwissenschaften

Christian Wagner
Dynamic Modeling of Turbopumps - Rotordynamics, Bearings and Contactless Seals

197 Seiten, Dissertation Technische Universität München (2019), Softcover, A5

Zusammenfassung / Abstract

In modern liquid rocket engines, turbopumps are used to convey the large amount of fuel and oxidant from the low-pressure tanks to the high-pressure combustion chamber. These turbopumps are lightweight, high-speed, and powerful turbo-machines. Vibrations in such a turbomachinery can lead to unwanted and even destructive consequences. In order to predict and avoid these undesired phenomena, a detailed representation of the dynamic behavior of the rotor-system is required, which is not only accurate but also computationally efficient.

This thesis investigates methodologies to create a representation of the dynamics of the turbopump structure coupled with different linear and nonlinear component models. Therefore, ball bearings and contactless seals are modeled in detail due to their great influence on the rotordynamics with their nonlinear, speed- and state-dependent behavior. Furthermore, the

investigated methods are formulated in such a way that they can be employed in condition monitoring and damage diagnosis for turbomachinery. To assess the developed methods and models for rotors, bearings, and seals, different numerical case studies have been developed and validated with literature data and corresponding experimental test rigs. Finally, a coupled multiphysical model of the rotor system is created to show the significant influence of the different component models and the improvement in the accuracy of predicting the dynamic behavior of turbopumps.