Numerical analysis of heat transfer characteristics of spray flames impinging on a wall under CI engine-like conditions

Design of Compression Ignition (CI) engines with improved thermal efficiencies needs better understanding the heat transfer mechanism from spray flame to combustion chamber wall. In this regard, occurring during interaction between impinging and wall, under CI engine-like conditions, is investigated in study using 3-Dimensional numerical simulations based on an Eulerian–Lagrangian framework. Simulations are performed for different fuel injection velocities (which representative pressures engines), examine their influence To couple convective radiative at wall surface conduction within finite thickness Conjugate Heat Transfer (CHT) incorporated simulations. A Non-Adiabatic Flamelet/Progress Variable (NA-FPV) approach employed as model n-dodecane, which considered be liquid spray. Dynamics film formed by droplets captured a particle-based approach. Contribution flux taken into consideration Discrete Ordinates (DO) method. Results indicate that total (sum fluxes) increases velocity. It observed largest stagnation zone where impinges directly surface, while becomes larger distance increases. Additionally, it found velocity flow rate rather small. This when expressed percentage rate, ranges ? 18% 30% (depending 3 cases investigated), indicating its contribution cannot neglected conditions present performed. Furthermore, characterize flame-wall process, correlations Nusselt number Nu (corresponding loss) Reynolds Re (of field) form Nu?Ren, analysed compared previous experimental assess applicability. that, depending how defined (either or flux), value correlation index n changes. When calculated includes 0.49 close n=0.4 reported recent experiments Toyota Central R&D Labs., Inc.