An application of C.F.M. model to a S.I. engine 3D combustion simulation: Validation and sensitivity analysis

Multidimensional numerical simulation of the combustion processes in spark ignition engines were performed using the Coherent Flame Model (CFM) which is based on the flamelet assumption. The CFM technique uses a transport equation to model the evolution of the flame surface, taking into account its advection, diffusion, production and destruction in a turbulent reacting flow. There are two model constants in a CFM approach, one associated with the flame production term and another with the destruction one. The goal of this work is to find a value for the above-mentioned constants able to obtain a good predictive capability of the combustion model varying the functional parameter of a S.I. multipoint injection engine. A comparison between experimental and numerical is carried out to test the combustion model. In order to start with appropriate initial fluid dynamic conditions the engine simulation take into account also the intake phase.