A Numerical Study on the Effect of a Pre-Chamber Initiated Turbulent Jet on Main Chamber Combustion
KAUST DepartmentKing Abdullah University of Science and Technology
Computational Reacting Flow Laboratory (CRFL)
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
Clean Combustion Research Center
Embargo End Date2022-09-29
Permanent link to this recordhttp://hdl.handle.net/10754/676401
MetadataShow full item record
AbstractTo elucidate the complex characteristics of pre-chamber combustion engines, the interaction of the hot gas jets initiated by an active narrow throated pre-chamber with lean premixed CH4/air in a heavy-duty engine was studied computationally. A twelve-hole KAUST proprietary pre-chamber geometry was investigated using CONVERGE software. The KAUST pre-chamber has an upper conical part with the spark plug, and fuel injector, followed by a straight narrow region called the throat and nozzles connecting the chambers. The simulations were run for an entire cycle, starting at the previous cycle's exhaust valve opening (EVO). The SAGE combustion model was used with the chemistry modeled using a reduced methane oxidation mechanism based on GRI Mech 3.0, which was validated against in-house OH chemiluminescence data from the optical engine experiments. Two different piston geometries, a flat piston geometry, and a more realistic bowl piston geometry were studied to understand the influence of jet on main chamber combustion. Varying the piston geometries results in different free jet times and hence main chamber combustion characteristics. Pre-chamber fuel ratio (PCFR) 6#x00025; of the total amount of fuel was investigated while keeping the global excess air ratios (?) condition a constant value of 2.0. Both piston cases resulted in similar pre-chamber pressurization, with almost the same pre-chamber discharge and the equal pressure difference between pre-and main-chamber ( "P) at the start of jet ejection. Different combustion behaviors were observed on analysis of the heat release rate in the main chamber. The importance of turbulence generated by the pre-chamber-initiated jets was further studied. It was observed that free jet time is a critical factor in developing turbulence in the main chamber. This increase in turbulence helps in increasing the burning velocity causing faster combustion. The influence of the jet-piston interaction is also analyzed as that determines the combustion behavior in the later CAD.
CitationSanal, S., Echeverri Marquez, M., Silva, M., Cenker, E., & Im, H. G. (2022). A Numerical Study on the Effect of a Pre-Chamber Initiated Turbulent Jet on Main Chamber Combustion. SAE Technical Paper Series. https://doi.org/10.4271/2022-01-0469
SponsorsThe paper is based upon work supported by Saudi Aramco Research and Development Center FUELCOM3 program under Master Research Agreement Number 6600024505/01. FUELCOM (Fuel Combustion for Advanced Engines) is a collaborative research undertaking between Saudi Aramco and KAUST intended to address the fundamental aspects of hydrocarbon fuel combustion in engines and develop fuel/engine design tools suitable for advanced combustion modes. The computational simulations utilized the Shaheen supercomputer at KAUST Supercomputing Laboratory. The authors thank Convergent Science Inc. for providing the CONVERGE license. The authors also acknowledge the contribution of Ponnya Hlaing for the engine experiments.
Conference/Event nameSAE 2022 Annual World Congress Experience, WCX 2022