Large-eddy simulation of tri-fuel ignition: diesel spray-assisted ignition of lean hydrogen–methane–air mixtures

We present 3D numerical results on tri-fuel (TF) combustion using large-eddy simulation and finite rate chemistry. The TF concept was recently introduced by Karimkashi et al. (Int. J. Hydrogen Energy, 2020) in 0D. Here, the focus is spray-assisted ignition of methane–hydrogen blends. spray acts as a high-reactivity fuel (HRF) while ambient premixed methane-hydrogen blend low-reactivity (LRF) mixture. Better understanding such process could enable motivate more extensive hydrogen usage e.g. compression marine engines where dual-fuel (DF) already utilised. studied set-up based modified ECN Spray A case, see Kahila (Combustion Flame, 2019) for DF combustion. pressure temperature are Tamb= 900 K pamb= 60 bar. content LRF varied systematically changing molar fraction 0≤x≤ 1, x=[H2][H2]+[CH4]. main added value study that we extend to 3D. particular findings follows: 1) Consistent with 2020, delays also effect becomes significant x≥ 0.5. 2) ratio between first- second-stage delay times (τ2τ1)0D≈2±0.1 (τ2τ1)3D≈3±0.3. Furthermore, 0D given τ23Dτ20D≈2±0.2 all cases. 3) Finally, consistent high-temperature heat release mode shown appear stronger than low-temperature compared methane–diesel