Large eddy simulations of hydrogen/methane jets in crossflows under engine-relevant conditions
type: CreativeWork
description: As the global energy sector shifts toward low-carbon alternatives, hydrogen has emerged as a promising fuel due to its high reactivity and zero-carbon emission potential. However, realising its full potential requires careful integration into existing combustion systems, particularly through fuel-flexible strategies such as hydrogen-methane blends. Among various fuel injection strategies, the jet in crossflow (JICF) presents a promising configuration for hydrogen in gas turbine applications, offering enhanced near-field mixing and favourable flame stabilisation characteristics. While the fundamental fluid dynamics of non-reacting JICF have been extensively studied, a detailed understanding of hydrogen combustion in these flows, especially under practical high-pressure conditions, remains limited. Moreover, the transitional development of hydrogen-methane blends introduces additional complexity in flame behaviour, fuel-air mixing, and pollutant formation, particularly when combustion occurs over a broad range of mixture fractions in partially premixed modes. This thesis addresses these concerns by employing high-fidelity Large Eddy Simulations (LES) with a presumed joint probability density function (PDF) model to investigate partially premixed combustion of hydrogen and hydrogen-methane blends in JICF configurations. The study focuses on three key aspects: (1) the influence of methane addition (∼ 0 to 25% by volume) on the combustion characteristics of a nitrogen-diluted hydrogen jet at atmospheric pressure, (2) the effect of elevated pressure (∼ 4 to 15 bar) on flame stabilisation and mixing behaviour in helium-diluted hydrogen jets, and (3) the combined and relative influence of pressure and hydrogen content on fuel consumption rates and chemical and flow timescales of a methane jet. At atmospheric pressure, the addition of methane broadens the flame and reduces the local heat release rate due to changes in chemical kinetics and mixing, with the peak value decreas…
abstract: As the global energy sector shifts toward low-carbon alternatives, hydrogen has emerged as a promising fuel due to its high reactivity and zero-carbon emission potential. However, realising its full potential requires careful integration into existing combustion systems, particularly through fuel-flexible strategies such as hydrogen-methane blends. Among various fuel injection strategies, the jet in crossflow (JICF) presents a promising configuration for hydrogen in gas turbine applications, offering enhanced near-field mixing and favourable flame stabilisation characteristics. While the fundamental fluid dynamics of non-reacting JICF have been extensively studied, a detailed understanding of hydrogen combustion in these flows, especially under practical high-pressure conditions, remains limited. Moreover, the transitional development of hydrogen-methane blends introduces additional complexity in flame behaviour, fuel-air mixing, and pollutant formation, particularly when combustion occurs over a broad range of mixture fractions in partially premixed modes. This thesis addresses these concerns by employing high-fidelity Large Eddy Simulations (LES) with a presumed joint probability density function (PDF) model to investigate partially premixed combustion of hydrogen and hydrogen-methane blends in JICF configurations. The study focuses on three key aspects: (1) the influence of methane addition (∼ 0 to 25% by volume) on the combustion characteristics of a nitrogen-diluted hydrogen jet at atmospheric pressure, (2) the effect of elevated pressure (∼ 4 to 15 bar) on flame stabilisation and mixing behaviour in helium-diluted hydrogen jets, and (3) the combined and relative influence of pressure and hydrogen content on fuel consumption rates and chemical and flow timescales of a methane jet. At atmospheric pressure, the addition of methane broadens the flame and reduces the local heat release rate due to changes in chemical kinetics and mixing, with the peak value decreas…
author: Murugavel, Aanantha Balaji
language: eng
keywords: Turbulent reacting flows, Jet in crossflow, Hydrogen-methane combustion
license: https://www.repository.cam.ac.uk/bitstreams/fb0a1cf3-8bdf-4cf1-8ceb-627cc2b0e07c/download
license: https://creativecommons.org/licenses/by/4.0/
date published: 2025-07-18
date modified: 2026-07-22T22:24:14Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.122769