Deakin University
Browse

File(s) under embargo

Influence of buoyancy on the mixing, flame structure, and production of NO in hydrogen diffusion flames

journal contribution
posted on 2024-03-08, 04:44 authored by M Manatunga, FC Christo, Jorg SchluterJorg Schluter, Sergiy ShelyagSergiy Shelyag
This study investigates the impact of buoyancy on the mixing and flame structure of hydrogen jet diffusion flames. A validated Computational Fluid Dynamics (CFD) model for hydrogen diffusion flames is developed, employing the k−ω turbulence model and a steady flamelet combustion model. By accounting for the buoyancy term, the model accurately predicts the stoichiometric hydrogen flame length within a mere 0.2% deviation from the experimental value. In contrast, excluding the buoyancy term leads to a prediction divergence of around 5%. Deeper analysis of the mixture fraction field indicates that buoyancy enhances mixing in the flame's far-field region, facilitating a more rapid dilution of the fuel stream within the air. This, in turn, results in a shorter flame. The scope of the modelling is expanded to encompass buoyancy effects on hydrogen flames with jet Reynolds numbers (ReJ) up to 15,000. While the buoyancy's influence on flame control weakens as ReJ increases, a noticeable ∼4% variation in stoichiometric flame length persists between scenarios with and without buoyancy.

History

Journal

International Journal of Hydrogen Energy

Volume

57

Pagination

328-337

Location

Amsterdam, The Netherlands

ISSN

0360-3199

eISSN

1879-3487

Language

English

Publication classification

C1 Refereed article in a scholarly journal

Publisher

PERGAMON-ELSEVIER SCIENCE LTD