Conceptual evaluation of hydrogen hybrid combustion for heavy-duty engines using CFD modelling

Hydrogen is a promising fuel for internal combustion engines (ICEs) due to its combustion properties and potential for zero carbon/low nitrogen oxide emissions. This study investigates a novel hydrogen combustion concept for heavy-duty engines using pre-chamber ignition technology operating in a hybrid combustion mode combining spark-ignition and diffusive combustion. Computational fluid dynamics (CFD) simulations were conducted using the commercially available software Siemens Star CCM+ with the In-Cylinder add-on and a complex chemistry combustion model. Multiple pre-chamber geometries were evaluated, focusing on parameters such as the number and flow area of pre-chamber nozzles, pre-chamber volume, and the implementation of a dual injector setup. A simplified valveless model and a detailed single-cylinder model were used to analyse flow and combustion characteristics at a fixed engine operating point (1000 RPM, single load). Results showed that increasing the nozzle flow area raised the peak apparent heat release rate but reduced overall combustion efficiency. More nozzles enhanced heat release during the main combustion phase and increased peak cylinder pressure. Reducing pre-chamber volume increased peak cylinder pressure by nearly 6%, but reduced combustion efficiency by 6.3%. Adding a second, direct-injection nozzle significantly improved combustion performance, raising total energy release by nearly 24% and achieving the highest combustion efficiency at 98.58%.

Grantor dc:publisher

Oxford Brookes University

Author dc:creator

• Brown, Travis

Contributors dc:contributor

• Bonatesta, Fabrizio

Statement dc:rights

• All rights reserved

Language dc:language

en

DOI dc:identifier

https://doi.org/10.24384/v4v4-nj92

OAI identifier oai:identifier

tle:ce83ec7b-9737-4dcc-a850-790a6e593dca:d6bd9758-527a-46cd-bfe2-c433766e8fca:1