Large eddy simulation of n-dodecane spray flame: Effects of injection pressure on spray combustion characteristics at low ambient temperature

The present study uses large-eddy simulations (LES) to identify the underlying mechanism that governs ignition and stabilization mechanisms of ECN Spray A flame for different injection pressures (Pinj) ambient temperatures (Tam). Two Pinj 50 MPa 150 MPa, as well two Tam 750 K 900 are considered. numerical model is validated against experimental fuel penetration, radial mixture fraction distribution, delay time, lift-off length. combustion characteristics all four spray flames predicted, with a maximum relative difference 15% measurements. At K, high-temperature (HTI) occurs in fuel-rich at head high flame, but periphery low flame. This due case having fuel-richer inner region. Nonetheless, both exhibit double-flame structure. HTI fuel-lean regions Pinj=50 respectively. Reducing leads lower velocity, less turbulent fluctuation, slower mixing, hence occurrence mixtures. exhibits triple-flame structure position, while lean premixed reaction zone. attributed distribution Despite differences structures, auto-ignition process plays key role stabilize position flames. also found be dependent on cool-flame products upstream position. In particular cases, heat transfer effect from main suggested contribute mechanisms.