An Analytical Study on Knocking Heat Release and its Control in a Spark Ignition Engine

1988 ◽  
Author(s):  
Yasuo Takagi ◽  
Teruyuki Itoh ◽  
Tamotsu Iijima
Keyword(s):  
Heat Release ◽  
Analytical Study ◽  
Spark Ignition ◽  
Spark Ignition Engine

Comparison Between Measured Radiance and a Radiation Model in a Spark-Ignition Engine

1990 ◽  
Vol 112 (3) ◽  
pp. 331-334 ◽  
Author(s):  
J. Yang ◽  
S. L. Plee ◽  
D. J. Remboski ◽  
J. K. Martin
Keyword(s):  
Heat Release ◽  
Release Rate ◽  
Maximum Rate ◽  
Spark Ignition ◽  
Rate Of Change ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Maximum Heat ◽  
Radiant Intensity ◽  
Maximum Heat Release

Measurements of the radiant emission in the near infrared have been obtained in a spark-ignition engine over a wide range of operating conditions. The system includes an in-cylinder optical sensor and associated detector. Prior work has shown correlations between the measured radiance and pressure quantities such as maximum cylinder pressure, crank angle of maximum pressure, and Indicated Mean Effective Pressure. Here are presented comparisons between the radiant intensity and a simplified model of the radiation emission, which demonstrate that the measured intensity is a function of the mass-burn fraction, mean burned-gas temperature, and the exposed combustion-chamber surface area. Further simplification leads to the conclusion that the time of the maximum rate of change of radiant intensity is the same as for the maximum heat-release rate, leading to the possibility of feedback control of spark timing. In addition, the magnitudes of the maximum rate of change of radiant emission and maximum heat-release rate have a linear relationship over a range of different operating conditions.

Numerical Investigation of Fuel Property Effects on Mixed-Mode Combustion in a Spark-Ignition Engine

2019 ◽  
Author(s):  
Chao Xu ◽  
Pinaki Pal ◽  
Xiao Ren ◽  
Sibendu Som ◽  
Magnus Sjöberg ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Propagation ◽  
Heat Release Rate ◽  
Release Rate ◽  
Octane Number ◽  
Mixed Mode ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Chemical Effect ◽  
Auto Ignition

Abstract In the present study, mixed-mode combustion of an E30 fuel in a direct-injection spark-ignition engine is numerically investigated at a fuel-lean operating condition using multidimensional computational fluid dynamics (CFD). A fuel surrogate matching Research Octane Number (RON) and Motor Octane Number (MON) of E30 is first developed using neural network based non-linear regression model. To enable efficient 3D engine simulations, a 164-species skeletal reaction mechanism incorporating NOx chemistry is reduced from a detailed chemical kinetic model. A hybrid approach that incorporates the G-equation model for tracking turbulent flame front, and the multi-zone well-stirred reactor model for predicting auto-ignition in the end gas, is employed to account for turbulent combustion interactions in the engine cylinder. Predicted in-cylinder pressure and heat release rate traces agree well with experimental measurements. The proposed modelling approach also captures moderated cyclic variability. Two different types of combustion cycles, corresponding to purely deflagrative and mixed-mode combustion, are observed. In contrast to the purely deflagrative cycles, mixed-mode combustion cycles feature early flame propagation followed by end-gas auto-ignition, leading to two distinctive peaks in heat release rate traces. The positive correlation between mixed-mode combustion cycles and early flame propagation is well captured by simulations. With the validated numerical setup, effects of NOx chemistry on mixed-mode combustion predictions are investigated. NOx chemistry is found to promote auto-ignition through residual gas recirculation, while the deflagrative flame propagation phase remains largely unaffected. Local sensitivity analysis is then performed to understand effects of physical and chemical properties of the fuel, i.e., heat of evaporation (HoV) and laminar flame speed (SL). An increased HoV tends to suppress end-gas auto-ignition due to increased vaporization cooling, while the impact of HoV on flame propagation is insignificant. In contrast, an increased SL is found to significantly promote both flame propagation and auto-ignition. The promoting effect of SL on auto-ignition is not a direct chemical effect; it is rather caused by an advancement of the combustion phasing, which increases compression heating of the end gas.

An Experimental Study of Cyclic Variations in a Lean Burn Natural Gas Fuelled Spark Ignition Engine

2003 ◽  
Author(s):  
A. Ramesh ◽  
Mohand Tazerout ◽  
Olivier Le Corre
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Pressure Rise ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
High Rate ◽  
Lean Burn ◽  
Complete Combustion ◽  
Average Value ◽  
Indicated Mean Effective Pressure

This work deals with the nature of cycle by cycle variations in a single cylinder, lean burn, natural gas fuelled spark ignition engine operated at a constant speed of 1500 rev/min under variable equivalence ratio, fixed throttle conditions. Cycle by cycle variations in important parameters like indicated mean effective pressure (IMEP), peak pressure, rate of pressure rise and heat release characteristics were studied. At the lean misfire limit there was a drastic increase in combustion duration. With mixtures leaner than the lean limit, good cycles generally followed poor cycles. However, the vice versa was not true. Cycles that had a high initial heat release rate lead to more complete combustion. A high rate of pressure rise led to a high IMEP. The IMEP of cycles versus their frequency of occurrence was symmetric about the average value when the combustion was good.

scholarly journals Modeling pre-spark heat release and low temperature chemistry of iso-octane in a boosted spark-ignition engine

2020 ◽  
Vol 212 ◽  
pp. 39-52 ◽  
Author(s):  
Dan A. DelVescovo ◽  
Derek A. Splitter ◽  
James P. Szybist ◽  
Gurneesh S. Jatana
Keyword(s):  
Low Temperature ◽  
Heat Release ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Low Temperature Chemistry
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