Numerical assessment of the effect of hydrogen enrichment of a technically premixed swirl-stabilized natural gas flame

Publicat en accés obert amb el permís explícit de l'editorial.High-fidelity large eddy simulations (LES) are conducted for lean natural gas flames with different levels of hydrogen enrichment in a technically premixed swirl-stabilized combustor (PRECCINSTA) operated at atmospheric pressure. The modelling approach relies on tabulation of premixed flamelets and presumed-shape probability density functions (PDF) to account for subgrid turbulence-chemistry interactions. Results are presented for non-reacting and reacting conditions with 0, 40 and 50% hydrogen content in the natural gas. The influence of hydrogen-enrichment is investigated here by combining LES with Raman measurements. The assessment of LES shows good predictions of the flame stabilization mechanism, flow field and flame dynamics as compared to experiments. The natural gas flame develops a self-excited flow oscillation characterized as a precessing vortex core, which is well reproduced by the LES. The lean operation of the burner with natural gas shows a stable M-shape flame that transitions to a V-shape fully attached flame as the main fuel is blended with hydrogen. Raman measurements are compared with LES data to examine the flame structure and burning characteristics. It is concluded that hydrogen addition makes the flame more compact, induces higher reactivity of the fuel-air mixture and leads to a stable V-shape flame fully attached to the burner’s nozzle-cone.This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 682383), the Center of Excellence in Combustion project (grant agreement No 952181), and the AHEAD PID2020-118387RB-C33 and ORION TRA2017-89139-C2-2-R projects from the Ministerio de Ciencia e Innovación. Leonardo Pachano acknowledges the Margarita Salas grant from Ministerio de Universidades (Spain) funded by the European Union-Next Generation EU. The authors thankfully acknowledge the computer resources from the RES (IM-2022-2-0003).Peer ReviewedPostprint (published version

Impact of wall heat transfer in Large Eddy Simulation of flame dynamics in a swirled combustion chamber

Heat transfer impact on Large Eddy Simulation