In-Cylinder Validation of a Method of Moments-Based Soot Model for Diesel Engines

Detailed soot models based on method of moments have been reported for combustion engines for more than twenty years. However, these models have always been validated against soot measured at exhaust and none of the modeling works have validated the spatial and temporal evolution of modeled soot with in-cylinder data. In this article a soot model based on method of moments has been evaluated by comparing simulations with the published experimental data for varying operating conditions of the heavy-duty optical engine at Sandia National Laboratories. Closed cycle combustion simulations have been performed using CONVERGE, a computational fluid dynamics solver for reacting multiphase flows. Before modeling soot, confidence in non-reactive modeling has been ensured by validating spray and equivalence ratio distributions from simulations with experimental optical images at different crank angles for each operating condition. Reduced kinetic schemes available in the literature for diesel engines have been assessed to identify the most promising one based on its performance across all operating conditions. The soot mass modeled by the method of moments has shown less sensitivity to the involved soot model constants, and a good agreement for temporal evolution and spatial soot distribution for the considered cases.