Design, development and testing of a high-pressure hydrogen micromix combustion rig
| dc.contributor.advisor | Nalianda, Devaiah | |
| dc.contributor.author | Giannouloudis, Alexandros | |
| dc.date.accessioned | 2025-05-20T16:25:50Z | |
| dc.date.available | 2025-05-20T16:25:50Z | |
| dc.date.freetoread | 2025-05-20 | |
| dc.date.issued | 2023-03 | |
| dc.description.abstract | The aviation industry has been improving aircraft performance and cutting back emissions for decades now. The increasing urgency of climate change has been pushing this effort to become more intense leading in recent years to the adoption of the target of full decarbonisation by 2050. Significant reductions in non-carbon containing emissions have been targeted by the industry as well. In that context, the use of liquid hydrogen (LH₂) as a combustible fuel for aircraft propulsion is a promising solution. Hydrogen guarantees carbon-free flights at mission level, yet, state-of-the-art aircraft combustor technologies are not suitable for low-NOₓ hydrogen combustion. Consequently, alternative combustion concepts and technologies are under research, and micromix technology is one of them. This thesis presents the design, development and deployment of a high-pressure combustion rig for hydrogen micromix burners, and describes the process from conception to testing of three different injector geometries. In doing so, it highlights the challenges of designing the components and systems to operate with hydrogen, whilst ensuring safety. Based on the experience gained through the deployment of the experimental setup, potential problems have been identified and solutions have been suggested to improve it. This aspect of the work contributes towards future research efforts of developing larger-scale combustion rigs for testing hydrogen. Within the context of the rig development, different design philosophies and manufacturing routes are explored for micromix burners. The limitations and safety considerations for the different approaches are detailed, and guidelines are offered on how the setup may be improved. The successful implementation of a fabrication strategy that combines additive manufacturing with traditional machining of features with sub-millimetre dimensions (0.3mm) is a significant contribution to developing micromix burners. It further opens an area of research into the limitations and potential effects of applying additive manufacturing to future micromix combustors. NOₓ emissions measurements of three injector configurations with different momentum flux ratios (MFRs) taken at elevated pressures, air-inlet temperatures and equivalence ratios are presented. The results denote the impact of these parameters on NOₓ emissions and the sensitivity of the emission to changes in MFR. Comparisons with LES results further highlight the need to accurately represent phenomena that affect the momentum flux ratio (MFR) in the simulations. Failure to do so provides a misleading correspondence of NOₓ levels with MFR. When compared to a state-of-the-art kerosene burner at similar pressure and inlet temperature conditions, hydrogen micromix yielded lower NOₓ by 50% for the ”worst” injector configuration. | |
| dc.description.coursename | PhD in Aerospace | |
| dc.identifier.uri | https://dspace.lib.cranfield.ac.uk/handle/1826/23902 | |
| dc.language.iso | en | |
| dc.publisher | Cranfield University | |
| dc.publisher.department | SATM | |
| dc.rights | © Cranfield University, 2023. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder. | |
| dc.subject | Hydrogen | |
| dc.subject | Hydrogen Combustion | |
| dc.subject | Hydrogen Micromix | |
| dc.subject | Momentum Flux Ratio | |
| dc.subject | Experiments | |
| dc.subject | Experimental Combustion | |
| dc.subject | Emissions Measurements | |
| dc.subject | NOx Emissions | |
| dc.subject | High Pressure | |
| dc.subject | High Temperature | |
| dc.subject | Rig Design | |
| dc.title | Design, development and testing of a high-pressure hydrogen micromix combustion rig | |
| dc.type | Thesis | |
| dc.type.qualificationlevel | Doctoral | |
| dc.type.qualificationname | PhD |