Numerical evidence on deflagration fronts in a methane/n-dodecane dual-fuel shear layer under engine relevant conditions

To date, high resolution spray-assisted dual-fuel (DF) studies have focused on capturing the ignition process while subsequent post-ignition events been largely neglected due to modeling requirements and computational cost. Here, we use a simplified approach for studying front evolution after ignition. Three-dimensional scale-resolved simulations of igniting shear layers (0≤Re≤1500) are studied better understand reaction fronts in engine-relevant conditions. We carry out quasi-DNS DF combustion setup consisting premixed n-dodecane/methane/air/EGR at 700K as fuel stream methane/air oxidizer pressure 60 atmospheres an ambient temperature 900 K. The flow solution is δ/10, where δ=laminar flame thickness. present study primarily focuses hypothesized formation its characterization. Under these conditions, indicate two-stage further leading initiation establishment. For Re<1500, resembling deflagration demonstrated close auto-ignition timescales. At Re=1500, mixing effects promote more rapid dilution slightly delayed although still observed. first time, rather short timescales 0.2−0.4 IDT (ignition delay time) ignition, provide numerical evidence emergence shear-driven processes via 3D 0<Re≤1500.