Page 59: of Maritime Reporter Magazine (November 2026)

FUTURE FUELS & COMBUSTION

Questioning the need an engine that is able to burn The Test Approach

Calculation Model it. Thanks to the university, we had The laboratory at the university

The polytropic index commonly access to both,” reveals Rogers. “We was equipped with a modern single- used in combustion analysis has been really did not know what to expect cylinder spark-ignition research en- well established and proven in many and would have been happy if noth- gine with variable valve timing, di- years of research on engines burning ing had shown up in our ? ndings. But rect fuel injection, and a dedicated hydrocarbon fuels. Other types of fuels, that was not the case.” port fuel injection for ammonia and however, differ signi? cantly in thermo- dynamic properties, ? ame speed, igni- tion characteristics, and speci? c heat ratio. The team at Kistler, a manufac- turer of piezoelectric pressure sensors, wanted to explore the sensitivity of this aspect, with respect to zero-carbon fu- els – and how much this might in? u- ence the results in engine development work. “We wondered whether param- eters proven in the research of carbon fuels would hold up when applied to zero carbon fuel combustion. So, we decided to look into it,” explains Dr.

David Rogers, Head of ICE Systems at Kistler, who led the study.

In collaboration with the Pow- ertrain Research Center, at the Uni- versity of Nottingham, the team decided to make the most of the op- portunity to work with the sophisti- cated test equipment and research en- gine that the facility has. The mixture of ammonia (NH ) and hydrogen is 3 increasingly considered a carbon-free fuel alternative with a high potential for heavy-duty combustion engines as used in marine propulsion applica- tions. Ammonia and hydrogen have combustion characteristics that differ signi? cantly from conventional car- bon fuels: while ammonia has a lower burning velocity than gasoline, hy- drogen has a higher one and their spe- ci? c heat ratios are different as well.

The Kistler team wanted to explore: are gasoline-based assumptions still valid for ammonia-hydrogen blends?

Or might they introduce systematic errors in burn-rate analysis, combus- tion phasing prediction, and ignition delay estimation? “Ammonia and hy- drogen are tricky to store. Also, you www.marinelink.com 59

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