SYSTEM ANALYSIS OF LOX/LNG EXPANDER BLEED ENGINE "LUMEN"

Kurzfassung

For the design, control and optimization of a chemical rocket engine, a thorough understanding of its behavior is needed. A complex interplay between combustion, fluid dynamics and mechanic components needs to be balanced. A system analysis is the basis for such an understanding, providing needed information for control strategies, and allowing predictions about the effects of changes to the system. For the technology demonstrator LUMEN such an analysis is used to evaluate its performance and identify areas for improvement. Within the scope of this thesis, existing models are compared to new engine test data to assess their validity. Due to deviations the existing models were improved and subsequently used to extrapolate the engine’s behavior to other operating conditions. With these, additional points of interest for future tests can be identified, alongside with bottlenecks for improvement of the engine. Finally the controllability of different variables using various subsets of valves was explored. It was found that in its current state, the maximum pump pressure of 150 bar limits LUMENs operational range most significantly. The operational flexibility for the nominal working point is in turn majorly constrained by the coolant mass flow requirement.