Preliminary Design of a Turbine Test Facility for Rocket Engine Applications

Abstract

This thesis presents the preliminary design of a modular, flexible turbine test facility for liquid rocket engine applications, aimed at enabling turbine-level testing at Technology Readiness Level 6 (TRL6) under hot, representative conditions. Existing facilities either lack flexibility or do not simultaneously reproduce the key operating parameters of pressure ratio, rotational speed, temperature, and driving medium, which limits turbine characterization and confidence in flight operation.
A three-phase methodology is adopted. First, top-level requirements are derived for turbines representative of 1 MN-class engines, and a scaling strategy is defined. The selected approach fixes Baljé specific speed and specific diameter, together with the inlet spouting Mach number, to preserve the main thermal and aero-mechanical phenomena while reducing power to a feasible range. Applying this methodology to a dataset of hydrogen–oxygen turbines yields a test envelope of roughly 3 M W shaft power at 30–50 krpm and defines the corresponding pressure, temperature, and mass-flow ranges for the facility.
In the second phase, several power-dissipation concepts are surveyed and modelled using zero- and one-dimensional analyses. A Pareto-based Analytic Hierarchy Process is then used to structure the trade-off. A self-designed, directly driven water pump with inducer and impeller stages is down-selected as the preferred concept, capable of absorbing 3 M W of power at 100 kg/s with a total pressure rise of 210 bar while avoiding cavitation through appropriate inlet pressurization.
The third phase focuses on the shaft support subsystem. A parametric rotordynamic model of the coupled turbine–pump shaft and pillow block is developed to derive stiffness, damping, load, and lubrication requirements for angular-contact ball bearings operating in the 30–50 krpm range. Results show that, with bearing stiffness in the 10⁷–10⁸ N/m range and moderate external damping, critical speeds can be placed outside the operating window, resonance crossings remain within acceptable displacement limits, and bearing loads and losses lie within achievable catalog values.
Overall, the work demonstrates the feasibility of a multi-MW turbine test facility that combines a high level of representativeness with broad flexibility, and provides ceiling requirements and subsystem concepts that form a concrete baseline for subsequent detailed design and eventual construction.