Knock Phenomenon Investigation in SI Engine Fuelled with Ammonia-Hydrogen Mixture Université d'Orléans

Format:

Book

Conference/Event

Author/Creator:

Hurault, Florian, author.

Contributor:

Brequigny, Pierre

Foucher, F. (Fabrice)

Rousselle, Christine

Conference Name:

2025 Sustainable Energy & Powertrains (2025-11-25 : Stuttgart, Germany)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2025

Summary:

Ammonia has emerged as a compelling carbon-free alternative fuel for applications in sectors such as power generation and heavy-duty transportation, where thermal energy conversion plays a dominant role. Its potential lies in its high hydrogen content, carbon-free combustion, and the feasibility of large-scale storage and transport. However, ammonia's combustion behavior poses significant challenges due to its low reactivity, characterized by a low laminar burning velocity, high autoignition temperature, and narrow flammability range. These properties hinder stable and efficient operation in conventional internal combustion engines. A common strategy to mitigate these limitations involves blending ammonia with hydrogenoften generated via on-board catalytic cracking of ammoniawhich improves ignition and flame speed. Despite these benefits, the presence of hydrogen increases the risk of knock, particularly in high-compression-ratio engines designed to improve thermal efficiency. This research focuses on evaluating knock phenomena associated with ammonia-hydrogen fuel blends in spark-ignition ICEs. First, a Methane Number was obtained for all ammonia-hydrogen blends to quantify the impact of hydrogen on ammonia knock reactivity under conditions close to those of the Motor Octane Number. The second part of this study explores the impact of knock for a fuel mixture consisting of 90% ammonia and 10% hydrogen by volume under varying engine parameters such as combustion chamber design and compression ratio on knock onset and severity. Experiments were conducted at engine speeds of 1000, 1500, and 2000 RPM, across intake pressures ranging from 1.0 to 1.8 bar (in 0.2 bar increments), equivalence ratios between 0.9 and 1.1, and intake temperatures of 60, 65, and 85°C. This study aims to identify the key parameters influencing knock intensity, onset, and distribution, as well as overall combustion properties

Notes:

Vendor supplied data

Publisher Number:

2025-01-0532

Access Restriction:

Restricted for use by site license