Turbulent Flame Propagation in a Spark Ignition Engine with an Unscavenged Horizontal Prechamber

Ryu, Hano; Asanuma, Tsuyoshi

doi:10.4271/881603

“…Several prechamber-specific CFD cases have been reported in the past, primarily with the KIVA and FLUENT software packages. Of these cases it has been typical practice to use greatly reduced single-digit equation reaction mechanisms while , if modelled, has been modelled with a form of the Zeldovich mechanism [43][44][45][46][47][48]. More elaborate models using a dedicated multi-step ignition model or a larger mechanism have been used but considering current capabilities, the treatment of chemistry in prechamber-specific cases can be improved [49][50].…”

Section: Previous Prechamber Cfd Modellingmentioning

confidence: 99%

Numerical simulation of liquid fuel prechamber ignition

Larson¹

2021

Preprint

0

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A Computational Fluid Dynamics (CFD) model was built that simulates the transient, compressible, reacting, multi-phase environment that exists within a reciprocating engine's combustion chamber(s). ANSYS Fluent v13.0 was used with the Euler-Lagrangian Discrete Phase Model (DPM), the Shell autoignition model, and the Large Eddy Simulation (LES) method of turbulence modeling. Validation of the spray dynamics was performed by comparing simulation results with experiments of liquid and vapour penetration length of an n-Heptane spray experiment done by Sandia National Laboratories. It was found that LES produced more accurate results than several Reynolds Averaged Navier-Stokes (RANS) models. The Shell autoignition model was coded to function with C10.17H19.91 and compared with experimental ignition results in a Rapid Compression Machine (RCM) environment. All of the above models were then combined to simulate a directly-fueled lean-burn combustion prechamber configuration wherein the effects of spray angle, timing, and duration were studied.

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“…Investigators form the Tokai University evaluated an horizontal unscavenged pre-chamber concept during the 80's decade [178][179][180][181]. Founding that an horizontal pre-chamber orientation leads to lower engine performances in terms of break mean effective pressures compared with a "conventional" vertical orientated pre-chamber.…”

Section: Figure 224mentioning

confidence: 99%

“…Including a pre-chamber has benefits in terms of combustion duration since the time to burn the total amount of fuel is reduced [40,71,97], thus letting the reduction in the total advance of the spark timing compared with the conventional spark ignition system. The possibility to reduce the need of the spark ignition advancement may be related to the improvement of the flame propagation speed [179].…”

Section: Spark Timingmentioning

confidence: 99%

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Implementation and Analysis of the Pre-Chamber Ignition Concept in a SI Engine for Passenger Car Applications

Martínez Hernándiz

0

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The global greenhouse gas emissions increase since the start of the Industrial Revolution has become a serious hazard to human life. In addition to power generation and industry, transportation, with the rise in the total vehicle number in the last decades, is one of the main contributors to this exponential increase of global warming-causing gases. In fact, cities such as Barcelona or Madrid, among many others, are imposing traffic restrictions to mitigate this situation. However, mankind is still on time to reverse this negative tendency and fix the environmental issue for the upcoming generations.The main goal of the present Thesis focuses on the study, implementation and analysis of the passive pre-chamber ignition concept in a near-future light-duty passenger car application. To be more specific, the investigation addresses the physical phenomena involving the combustion process when pre-chamber ignition system is used in a spark-ignition engine. Then, some strategies to improve thermal efficiency while employing this concept are applied. Finally, with all the knowledge gathered, basic guidelines for a pre-chamber pre-design are presented.The first approach to the concept consists of its direct implementation in the engine, obtaining experimental results in three different operating conditions in terms of engine load and speed. Furthermore, different prechamber geometries are also evaluated. Although its direct implementation is relatively straightforward by exchanging the spark plug, understanding some of the relevant phenomena related to the combustion process, such as gas exchange or jet-tip penetration, is extremely difficult without the support of computational tools. This is the main reason supporting the use of 1D numerical tools in the present Thesis, since with proper modeling based on experimental data, further knowledge can be obtained in those situations where experimental evaluations are not feasible. These 1D tools have the benefits of their low computational cost and their ability to provide reasonably good results in a short period of time. ix xv[8] F. D. Sabatino, P. J. Martinez-Hernandiz, R. N. Rosa, and I. Ekoto. "Investigation of the effects of passive pre-chamber nozzle pattern and ignition system on engine performance and emissions". International Journal of Engine Research 0 (0), 2022.

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Numerical simulation of liquid fuel prechamber ignition

Larson¹

2021

Preprint

0

View full text Add to dashboard Cite

A Computational Fluid Dynamics (CFD) model was built that simulates the transient, compressible, reacting, multi-phase environment that exists within a reciprocating engine's combustion chamber(s). ANSYS Fluent v13.0 was used with the Euler-Lagrangian Discrete Phase Model (DPM), the Shell autoignition model, and the Large Eddy Simulation (LES) method of turbulence modeling. Validation of the spray dynamics was performed by comparing simulation results with experiments of liquid and vapour penetration length of an n-Heptane spray experiment done by Sandia National Laboratories. It was found that LES produced more accurate results than several Reynolds Averaged Navier-Stokes (RANS) models. The Shell autoignition model was coded to function with C10.17H19.91 and compared with experimental ignition results in a Rapid Compression Machine (RCM) environment. All of the above models were then combined to simulate a directly-fueled lean-burn combustion prechamber configuration wherein the effects of spray angle, timing, and duration were studied.

show abstract

Turbulent Flame Propagation in a Spark Ignition Engine with an Unscavenged Horizontal Prechamber

Cited by 4 publications

References 14 publications

Numerical simulation of liquid fuel prechamber ignition

Numerical simulation of liquid fuel prechamber ignition

Implementation and Analysis of the Pre-Chamber Ignition Concept in a SI Engine for Passenger Car Applications

Numerical simulation of liquid fuel prechamber ignition

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