Effect of Temperature Conditions on Flame Evolutions of Turbulent Jet Ignition

Turbulent jet ignition technology can significantly improve lean combustion stability and suppress engine knocking. However, the narrow jet channel between the pre-chamber and the main chamber leads to some difficulties in heat exchange, which significantly affects combustion performance and mechanical component lifetime. To clarify the effect of temperature conditions on combustion evolutions of turbulent jet ignition, direct numerical simulations with detailed chemical kinetics were employed under engine-relevant conditions. The flame propagation in the pre-chamber and the early-stage turbulent jet ignition in the main chamber were investigated. The results show that depending on temperature conditions, two types of flame configuration can be identified in the main chamber, i.e., the normal turbulent jet flame propagation and the spherical flame propagation, and the latter is closely associated with pressure wave disturbance. Under low-temperature conditions, the cold jet stoichiometric mixtures and the vortexes induced by the jet flow determine the early-stage flame development in the main chamber. Under intermediate temperature conditions, pre-flame heat release and leading pressure waves are induced in the jet channel, which can be regarded as a transition of different combustion modes. Whereas under high-temperature conditions, irregular auto-ignition events start to occur, and spherical flame fronts are induced in the main chamber, behaving faster flame propagation.

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Combustion modelling of turbulent jet ignition in a divided combustion chamber

International Journal of Engine Research ◽

10.1177/14680874211037118 ◽

2021 ◽

pp. 146808742110371

Author(s):

Mattia Olcuire ◽

Clara Iacovano ◽

Alessandro d’Adamo ◽

Sebastiano Breda ◽

Tommaso Lucchini ◽

...

Keyword(s):

Volume Ratio ◽

Turbulent Jets ◽

Combustion Regime ◽

Nozzle Diameter ◽

Turbulent Jet ◽

Main Chamber ◽

Lean Burn ◽

Jet Flame ◽

Chamber Volume ◽

Combustion Modelling

Turbulent jet ignition is seen as one of the most promising strategies to achieve stable lean-burn operation in modern spark-ignition engines thanks to its ability to promote rapid combustion. A nearly stoichiometric mixture is ignited in a small-volume pre-chamber, following which multiple hot turbulent jets are discharged in the main chamber to initiate combustion. In the present work, a detailed computational investigation on the turbulent combustion regime of premixed rich propane/air mixture in a quiescent divided chamber vessel is carried out, to study the characteristics of the jet flame without the uncertainties in mixing and turbulent conditions typical of real-engine operations. In particular, the paper investigates the dependency of flame propagation on nozzle diameter (4, 6, 8, 12 and 14 mm) and pre-chamber/main-chamber volume ratio (10% and 20%); CFD results are compared to the experimental outcomes. Results show that the combustion regime in the quiescent pre-chamber follows a well-stirred reaction mode, rendering the limitation in using conventional flamelet combustion models. Furthermore, due to the very high turbulence levels generated by the outflowing reacting jets, also the main chamber combustion develops in a well-stirred reactor type, confirming the need for a kinetics-based approach to combustion modelling. However, the picture is complicated by thickened flamelet conditions possibly being verified for some geometrical variations (nozzle diameter and pre-chamber volume). The results show a general good alignment with the experimental data in terms of both jet phasing and combustion duration, offering a renewed guideline for combustion simulations under quiescent and low Damköhler number conditions.

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Hydrodynamic instability and shear layer effect on the sound emission of a turbulent jet flame

21st AIAA/CEAS Aeroacoustics Conference ◽

10.2514/6.2015-2380 ◽

2015 ◽

Cited By ~ 1

Author(s):

Stephan Schlimpert ◽

Seong Ryong Koh ◽

Antje Feldhusen ◽

Benedikt Roidl ◽

Matthias H. Meinke ◽

...

Keyword(s):

Shear Layer ◽

Hydrodynamic Instability ◽

Turbulent Jet ◽

Sound Emission ◽

Jet Flame ◽

Layer Effect

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Cinema particle imaging velocimetry time history of the propagation velocity of the base of a lifted turbulent jet flame

Proceedings of the Combustion Institute ◽

10.1016/s1540-7489(02)80230-9 ◽

2002 ◽

Vol 29 (2) ◽

pp. 1897-1903 ◽

Cited By ~ 33

Author(s):

Ansis Upatnieks ◽

James F. Driscoll ◽

Steven L. Ceccio

Keyword(s):

Propagation Velocity ◽

Time History ◽

Turbulent Jet ◽

Particle Imaging Velocimetry ◽

Jet Flame ◽

History Of ◽

Particle Imaging

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Effect of temperature on photosynthesis of lettuce adapted to different light and temperature conditions

Scientia Horticulturae ◽

10.1016/0304-4238(80)90075-8 ◽

1980 ◽

Vol 13 (2) ◽

pp. 115-123 ◽

Cited By ~ 13

Author(s):

H.P. Lorenz ◽

H.J. Wiebe

Keyword(s):

Effect Of Temperature ◽

Temperature Conditions

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Effects of radiation absorption on spherical flame propagation and radiation-induced uncertainty in laminar flame speed measurement

Proceedings of the Combustion Institute ◽

10.1016/j.proci.2016.05.003 ◽

2017 ◽

Vol 36 (1) ◽

pp. 1129-1136 ◽

Cited By ~ 26

Author(s):

Zheng Chen

Keyword(s):

Flame Propagation ◽

Laminar Flame ◽

Flame Speed ◽

Radiation Absorption ◽

Laminar Flame Speed ◽

Spherical Flame ◽

Speed Measurement ◽

Radiation Induced ◽

Effects Of Radiation ◽

Spherical Flame Propagation

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Modeling the formation and growth of instabilities during spherical flame propagation

Proceedings of the Combustion Institute ◽

10.1016/j.proci.2018.07.098 ◽

2019 ◽

Vol 37 (3) ◽

pp. 3669-3676 ◽

Cited By ~ 8

Author(s):

C. Regis L. Bauwens ◽

Jeffrey M. Bergthorson ◽

Sergey B. Dorofeev

Keyword(s):

Flame Propagation ◽

Spherical Flame ◽

Spherical Flame Propagation

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Comparative study on combustion characteristics of lean premixed CH4/air mixtures in RCM using spark ignition and turbulent jet ignition in terms of orifices angular position change

Combustion Engines ◽

10.19206/ce-2019-105 ◽

2019 ◽

Vol 176 (1) ◽

pp. 36-41 ◽

Cited By ~ 1

Author(s):

Wojciech BUESCHKE ◽

Maciej SKOWRON ◽

Krzysztof WISŁOCKI ◽

Filip SZWAJCA

Keyword(s):

Internal Combustion Engines ◽

Positive Impact ◽

Angular Position ◽

Turbulent Jet ◽

Combustion Stability ◽

Optical Observations ◽

Charge Movement ◽

Position Change ◽

Lean Burn ◽

The Impact

The increase in ignitability consist a main aim of implementation of the turbulent jet ignition (TJI) in relation to the combustion of diluted charges. Such an ignition system has been introduced to the lean-burn CNG engine in the scope of GasOn-Project (Gas Only Internal Combustion Engines). In this study the impact of TJI application on the main combustion indexes has been investigated using RCM and analyzed on the bases of the indicating and optical observations data. The images have been recorded using LaVision HSS5 camera and post-processed with Davis software. Second part of the study based on indicating measurements consist the analysis of combustion regarding the variation in the geometry of pre-chamber nozzles. It has been noted, that combustion with TJI indicates signi- ficantly bigger flame luminescence and simultaneously – faster flame front development, than the combustion initiated with conventional SI. The positive impact of nozzles angular position on engine operational data has been found in the static charge movement conditions, regarding the combustion stability.

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