ECO-THRUST: DESIGNING A LIQUID HYDROGEN ROCKET NOZZLE WITH COMPRESSED AIR VALIDATION FOR SUSTAINABLE PROPULSION

Abstract

This action research presents the development of a high-efficiency convergent-divergent nozzle designed for a small-scale liquid hydrogen (LH2) rocket engine, contributing to sustainable aerospace propulsion through Technical and Vocational Education and Training (TVET). The project employed a plan-act-observe-reflect cycle to optimize nozzle design, theoretically leveraging the clean combustion characteristics of LH2 to reduce fuel consumption and enhance environmental sustainability. The nozzle was designed using computer-aided design (CAD) tools, applying principles of thermodynamics and fluid dynamics to maximize exhaust velocity for an LH2-based system. For safe and practical validation, static thrust tests were conducted using compressed air as a simulant propellant to assess the nozzle’s structural integrity and thrust measurement system. Stainless steel, chosen for its recyclability and mechanical strength, was machined into an integrated nozzle-combustion chamber structure to ensure durability. Tests demonstrated effective thrust generation, with the test cart displacing 0.25 cm in 0.6 seconds at initial thrust and 2.5 cm in 0.2 seconds at peak thrust, validating the design’s performance under simulated conditions. Challenges such as pressure spikes due to increased propellant flow and machining imperfections underscored the need for precision fabrication. Reflections highlighted the importance of sustainable manufacturing and safe testing practices in TVET, promoting green engineering. This study enhances practical competencies in design, machining, and performance analysis, reinforcing TVET’s role in advancing low-emission propulsion systems for reusable launch vehicles and climate monitoring applications.