Work

Large Eddy Simulation of Lean Premixed Hydrogen/Methane Bunsen Flames: Effects of Hydrogen Content and Pressure

Year: 2026

Type: article

Abstract: Hydrogen/methane (H 2 /CH 4 ) blends serve as a transitional fuel for gas turbines, offering a pathway toward cleaner energy by reducing carbon emissions while leveraging existing natural gas infrastructure. Understanding the effects of H 2 content and pressure on the flame shape is essential for safe operation and optimising combustion performance. In this work, turbulent lean premixed Bunsen H 2 /CH 4 flames are studied using large eddy simulation (LES), focusing on the flame brush length ( f l ) and thickness ( f b ) along the centreline. The results have been compared with available measurements for validation. The findings indicate that increasing H 2 content leads to shorter and thinner flames, while the pressure effects are minimal. At the lower H 2 content (≤30% by volume), the change in f l is relatively small, whereas at the higher H 2 content ( > 30% by volume), f l decreases linearly with increasing H 2 content. Similarly, the values of f b decrease as H 2 content is increased. This phenomenon is primarily due to the increased turbulent flame speed ( s T ) resulting from enhanced fuel reactivity. The limited pressure effects on f l and f b are attributed to the consistent s T , maintained by the synergistic interactions between chemical reactions and turbulent characteristics. Furthermore, this study highlights the transition of the flame regime from the corrugated flamelet regime to the thin reaction zone regime along the axial direction. This transition occurs further upstream in flames with higher H 2 content, driven by the increased flame speed. Additionally, the reaction progress variable contours and profiles show that the H 2 addition also leads to a radial thinning of the flame, while pressure has little effect on the overall flame shapes.

Source: Flow Turbulence and Combustion

DOI: 10.1007/s10494-026-00730-6

Authors: Yecan Liu, James C. Massey, Filippo Faldella, Yusuke Tanaka, Nedunchezhian Swaminathan

Institutions: University of Cambridge, Paul Scherrer Institute, Mitsubishi Heavy Industries (Japan)

Language: English

Topic: Combustion and flame dynamics

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $2,590