CFD study of low soot spray combustion in a heavy-duty diesel engine
This CFD study focuses on the influence of the nozzle diameter on the mixing process and the soot formation and oxidation process in a heavy-duty diesel engine. The CAD simulation is based on the Reynolds Averaged Navier-Stokes approach. The engine set-up is similar to an experimental case that enables smokeless spray combustion. The aim of the paper is to improve the understanding of the physics of the mixing process in a real engine environment with the attention to scrutinize its effect on combustion and soot emission. Two non-reacting cases with different nozzle diameters but constant injection pressure and their corresponding reacting cases are simulated with dynamic mesh motion and fuel spray modeling. The influence of combustion on the mixing process is analysed and the simulation results are compared with the measurement data. The differences in the mixing process between a constant volume vessel and a dynamic combustion chamber with piston motion are evidenced.