March 6 - 8, 2017 | Berlin
LEADING ENGINEERING SIMULATION CONFERENCE
Evaluation of the flame propagation in an engine simulated with the ECFM combustion model
In the present work simulation results are compared to VisioFlame measurements. Two different operating conditions are evaluated regarding the flame propagation. The rotational speed of the engine is kept constant while the load is varied. For the conducted investigation a four cylinder gasoline engine with a compression ratio of ten was used. The two liter turbo charged engine is equipped with a side injection. The experimental data indicates a significant difference in burn duration (flame speed) as well as the preferred direction of flame growth for the two evaluated operating conditions.
Unsteady RANS simulations with the software pro-STAR were performed for the operating conditions mentioned above. The ECFM model was used to simulate the combustion and the ISSIM model to capture the ignition process as well as the first flame kernel growth.
For the low pressure condition a preferable flame growth towards the exhaust port is predicted while for the high pressure case the flame tends to propagate faster towards the intake side. The same preferable propagation of the flame could be identified in the VisioFlame measurements. This enables the simulation to be used as a diagnostic tool to reveal the physical explanation for the different flame propagation.