Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
SIMULATION OF AN INTERNAL COMBUSTION ENGINE USING ECFM-3Z COMBUSTION MODEL IN A CFD 3D COMMERCIAL CODE COMPARED TO EXPERIMENTAL RESULTS
Submission Author:
LEONARDO FONSECA , MG
Co-Authors:
Rudolf Huebner, Raphael Braga, Luiz Fernando Morais, Ramon Molina Valle
Presenter: LEONARDO FONSECA
doi://10.26678/ABCM.ENCIT2016.CIT2016-0327
Abstract
This paper presents the results of simulation of an internal combustion engine using Extended Coherent Flame Model – 3 Zones (ECFM-3Z) combustion model in a Computational Fluid Dynamics (CFD) 3D commercial code, compared to experimental results for the same engine. The commercial code solves equations for conservation of mass, momentum, energy, RNG k-ε turbulence model, coupled with a model for near wall flow field, using the finite volume method. The 3D mesh model involves the internal volume of the cylinder, intake and exhaust ports, and takes into account the movement of the piston and valves by moving the mesh. It solves the mesh movement by adding and removing mesh layers in the cylinder, bellow and above valves. Grid independence studies are performed in order to make the results independent from the mesh. Mesh refinement is performed using characteristic length of the mesh at cylinder, intake and exhaust ports, so the characteristic length would be as close as possible the same for all regions. The ECFM-3Z model has empirical constants for adjustment, and so it needs experimental results not only for adjustment but also for validation. They are modified in order to make the results for in cylinder pressure, temperature, heat release rate and mass burned fraction as close as possible to the experimental ones. The model takes into account only one cylinder of the engine, which runs at 2100 rpm, 20% MBT and uses VVT. Results of the CFD model for two positions of VVT are compared to experimental ones for the conditions, in order to evaluate the behavior of the combustion model under these conditions. The CFD results for in cylinder pressure for both cases are well correlated to experimental ones, although in cylinder temperature, heat release rate and mass burned fraction are not as well correlated.
Keywords
3-D CFD modelling, INTERNAL COMBUSTION ENGINES, ECFM-3Z, STAR-CD, 3-D CFD modelling, INTERNAL COMBUSTION ENGINES, ECFM-3Z, STAR-CD
