Assessment of turbulent combustion models for simulating pre-chamber ignition in a natural gas engine

Conference · Wed Jan 01 04:00:00 EST 2020

DOI:https://doi.org/10.1115/ICEF2019-7278· OSTI ID:1632175

Kim, Joohan; Scarcelli, Riccardo; Som, Sibendu; Shah, Ashish; Biruduganti, Munidhar S.; Longman, Douglas E.

Lean combustion in an internal combustion engine is a promising strategy to increase thermal efficiency by leveraging a more favorable specific heat ratio of the fresh mixture and simultaneously suppressing the heat losses to the cylinder wall. However, unstable ignition events and slow flame propagation at fuel-lean condition lead to high cycle-to-cycle variability and hence limit the high-efficiency engine operating range. Pre-chamber ignition is considered an effective concept to extend the lean operating limit, by providing spatially distributed ignition with multiple turbulent flame-jets and enabling faster combustion rate compared to the conventional spark ignition approach. From a numerical modeling perspective, to date, still the science base and available simulation tools are inadequate for understanding and predicting the combustion processes in pre-chamber ignited engines. In this paper, conceptually different RANS combustion models widely adopted in the engine modeling community were used to simulate the ignition and combustion processes in a medium-duty natural gas engine with a pre-chamber spark-ignition system. A flamelet-based turbulent combustion model, i.e., G-equation, and a multi-zone well-stirred reactor model were employed for the multi-dimensional study. Simulation results were compared with experimental data in terms of in-cylinder pressure and heat release rate. Finally, the analysis of the performance of the two models is carried out to highlight the strengths and limitations of the two formulations respectively.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE); USDOE Office of Energy Efficiency and Renewable Energy (EERE) - Office of Vehicle Technologies (VTO)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1632175
• Country of Publication: United States
• Language: English

Related Subjects

combustion model evaluation
natural gas engines
pre-chamber ignition
turbulent flame jet
turbulent jet ignition