Design and Control Challenges for the LUMEN LOX/LNG Expander-Bleed Rocket Engine

Abstract

This paper investigates the design and operational challenges of LOX/LNG liquid propellant rocket engines, with a focus on key components. For the injector head, challenges such as flame anchoring and injection temperature are examined. The turbopumps present challenges related to rotordynamics, high-cycle fatigue, cavitation, and efficiency. In the case of the regenerative cooling system, the challenge lies in designing it to withstand high structural temperatures, which is crucial for expander-bleed engines that rely on the enthalpy pickup in the cooling system to drive the turbines. The system behavior of the LUMEN expander-bleed rocket engine is analyzed to determine its design and operational envelope. A simulation model built on recent experimental data establishes a database of steady-state data points for analysis. Additionally, control challenges are identified, and potential control algorithms suitable for rocket engine control are discussed.