Open Access

ARTICLE

Effect of Inclined Wall on Quenching Distance, Thermochemical State and CO Emission Characteristics of Methane/Hydrogen/Air Premixed Jet Flame

Feiyang Li¹, Jianfeng Pan^1,*, Yuejin Zhu¹, Zhongjia Li¹, Yi Zhang¹, Muhammad Nauman¹, Wenming Yang²
1 School of Energy and Power Engineering, Jiangsu University, Zhenjiang, China
2 Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, Singapore
* Corresponding Author: Jianfeng Pan. Email:

Energy Engineering https://doi.org/10.32604/ee.2026.078049

Received 23 December 2025; Accepted 18 March 2026; Published online 18 May 2026

Abstract

Flame-wall interaction (FWI) is a common phenomenon in enclosed combustion systems. Under the influence of the wall, flames may undergo quenching or exhibit reduced reaction intensity, leading to an increase in unburned fuel in the near-wall region. This study establishes a 3D numerical model using CFD software to simulate the combustion process of methane/hydrogen/air premixed jet flames under inclined wall conditions, with validation against experimental data. Simulations of the quenching process under inclined walls were performed, revealing the effects of variations in tilt angle (θ) and hydrogen content (αH2) on the flame quenching, thermochemical state, and CO emissions. With the increase in θ, the normal velocity increases, the flame moves away from the wall, and the quenching distance increases. As αH2 increases, the burning velocity increases, the flame moves closer to the wall, and the quenching distance decreases. The thermochemical state was analyzed using carbon monoxide (CO) concentration and temperature distributions. When the temperature is below 1000 K, convection and diffusion dominate the distribution of CO. As θ and αH2 increase, both convection and diffusion intensify. During CO emission processes, the near-wall region contributes over 60% of the total CO emissions. As θ increases, CO emissions first decrease and then increase for αH2 = 0% and 20%, whereas at αH2 = 40%, CO emissions exhibit a gradual increase. As αH2 increases, the competitive consumption of OH by reaction R40 (H₂ + OH = H₂O + H) intensifies, which weakens CO oxidation and leads to elevated CO emissions.

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Keywords

Inclined wall; quenching distance; thermochemical state; CO emissions; flame-wall interaction

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