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Effect of Discharge Energy Distribution on Flame Kernel Development
ASME 2020 Internal Combustion Engine Division Fall Technical Conference, 2020Abstract The early flame kernel initiation and development are essential to a successful combustion process, especially under lean burn/EGR diluted conditions. Multiple ignition sites strategy has shown promise to secure the flame kernel initiation under extreme engine operating conditions. Two factors are considered to contribute to the
Linyan Wang +5 more
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Growth Rate and Flame Structure of Turbulent Premixed Flame Kernels in Supersonic Flows
54th AIAA Aerospace Sciences Meeting, 2016A fundamental study of the radial growth and flame surface characteristics of freely propagating spherical flames is conducted in a 50 × 50 mm, M = 1.5 supersonic wind tunnel. Free stream turbulence is enhanced via passive and active turbulence generators upstream of the converging-diverging nozzle.
Bradley A. Ochs +3 more
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Modeling the Initial Growth of the Plasma and Flame Kernel in S.I. Engines
Volume 2: In-Cylinder Processes: Fuel Spray, Flow, Ignition, Combustion, and Emission Formation, 2001Abstract The initial size and growth of the plasma and flame kernel just after spark discharge in S.I. engines determines if the flame becomes self-sustainable or extinguishes. On the other hand the development of the kernel during the initial phases has non-negligible influences on the further combustion.
H. Willems, R. Sierens
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Flame surface density distribution in turbulent flame kernels during the early stages of growth
Proceedings of the Combustion Institute, 2009Abstract Direct numerical simulations (DNS) of flame kernels with single-step chemistry are used to asses the influence of the initial turbulent energy spectra on the global evolution of the kernel, and the distribution of flame surface density (FSD) in the flame brush.
T.D. Dunstan, K.W. Jenkins
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Direct Numerical Simulation of Turbulent Flame Kernels
1999A combustion DNS code has been developed to solve a fully compressible reacting flow and applied to studying the effects of a turbulent flame kernel. High accuracy numerical techniques have been employed which are 10th order explicit in space and a third order explicit Runge Kutta method in time.
Karl W. Jenkins, R. Stewart Cant
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The Effects of Charge Motion on Early Flame Kernel Development
SAE Technical Paper Series, 1993<div class="htmlview paragraph">The fiber optic spark plug was used in conjunction with a piezoelectric pressure transducer to collect combustion diagnostic data on four production engines designed to generate quiescent, swirl, and tumble charge motions. Spark advance was varied under low speed, low load conditions to investigate changes in flame
David L. Lord +3 more
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The evolution of autoignition kernels in turbulent flames of dimethyl ether
Combustion and Flame, 2018Abstract Simultaneous planar laser-induced fluorescence (PLIF) imaging of CH2O and OH was performed at a repetition rate of 10.kHz, jointly with chemiluminescence to explore autoigniting dimethyl ether (DME) flames in a hot vitiated coflow burner. The focus of the study is the imaging of the flame stabilization region and the temporal evolution of ...
Andrew R.W. Macfarlane +3 more
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Chemical effects of plasma gases on flame kernel development
Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, 1988Abstract A study of the plasma jet ignition of lean methane-air mixtures was conducted to determine the effect of different plasma gases on flame kernel development. A plasma igniter, incorporating a shutter that separated the gases in the igniter from the reactant gases in a combustion chamber before discharge, allowed any ...
S. R. Vosen +2 more
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A regime diagram for premixed flame kernel-vortex interactions
Physics of Fluids, 2007Direct numerical simulations of flame kernel-vortex interactions are implemented in an axisymmetric configuration using a two-step global mechanism to study the different combustion regimes of the interactions. Four combustion regimes have been identified.
Echekki, Tarek, Kolera-Gokula, Hemanth
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Modeling Nanosecond-Pulsed Spark Discharge and Flame Kernel Evolution
Journal of Energy Resources Technology, 2020Abstract Dilute combustion, either using exhaust gas recirculation or with excess air, is considered a promising strategy to improve the thermal efficiency of internal combustion engines. However, the dilute air-fuel mixture, especially under intensified turbulence and high-pressure conditions, poses significant challenges for ...
Joohan Kim +4 more
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