Achieving Lagrangian-esque Fuel Mass Tracking in an Eulerian Frame of Reference CFD Diesel Engine Simulation

Diesel combustion is a highly heterogeneous process in which the fuel must undergo several sub-processes after injection in order to release its heat through combustion. Prior to evaporation, computational fluid dynamic (CFD) simulations track the injected fuel mass using a Lagrangian frame of reference to determine the pathlines of the liquid fuel in the gaseous environment. However, after evaporation, when the fuel mass becomes part of the working fluid, it is no longer tracked in a Lagrangian reference frame as it undergoes its mixing and combustion processes. To gain deeper insights into the diesel combustion process, a methodology is proposed to track the evolution of fuel mass packets while in the gaseous state attaining a Lagrangian-esque description of the fuel’s evolution. This is achieved using the commercially available capabilities in Convergent Science’s CFD package, without requiring user-defined functions. The methodology is applied to a heavy-duty diesel engine and shows how fuel evolution differs during different stages of combustion. Post-processing of the data is discussed, and a method of heat release analysis is proposed.