scholarly journals Numerical analysis of spark plugs number influence on selected parameters of combustion in piston engine

2008 ◽  
Vol 132 (1) ◽  
pp. 50-55
Author(s):  
Arkadiusz KOCISZEWSKI
Keyword(s):  
Numerical Analysis ◽  
Numerical Modelling ◽  
Computational Analysis ◽  
Combustion Process ◽  
Graphical Form ◽  
Si Engine ◽  
Spark Plug ◽  
Crank Angle ◽  
3D Numerical Modelling ◽  
Lean Mixtures

The results of numerical analysis of combustion in multi-spark plug SI engine are presented in the paper. The outcome of computational analysis of lean mixtures combustion in engine with one and two spark plugs are compared. The output data was presented in graphical form as screenshots (temperature distribution) and as pressure and temperature courses in function of crank angle. 3D numerical modelling of combustion in multi-spark plug engine proved that improvement in lean mixture combustion process can be obtained by increasing the number of active ignition points. As conclusion it can be stated that numerical modelling results confirmed the favourable influence of applying two active spark plugs in lean mixtures combustion.

scholarly journals Numerical modelling of combustion in SI engine fuelled with methane

2009 ◽  
Vol 139 (4) ◽  
pp. 45-54
Author(s):  
Arkadiusz KOCISZEWSKI
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Numerical Analysis ◽  
Numerical Modelling ◽  
Si Engine ◽  
Exhaust Gases ◽  
Spark Plug ◽  
Paper Work ◽  
Lean Mixtures ◽  
Excess Number

Results of numerical analysis of methane and gasoline combustion in multipoint ignition SI engine are presented in the paper. Work parameters of engine fuelled with methane lean mixtures of λ = 1.45 and 1.8 for three configurations of spark plugs (one, two and four active spark plugs) are compared. These configurations were chosen taking into consideration earlier research concerning numerical modelling and experiments. The results of carried out analysis proved that using two spark plugs at air excess number λ = 1.8 caused that engine work parameters are similar to case of mixtures of λ = 1.45 with one spark plug configuration. Simultaneously, the emission of nitric oxide was decreased more than eight times and the concentration of carbon dioxide in exhaust gases was 20% lower.

scholarly journals Performances of a Research CFR Octane Rating Unit Engine and Dacia Single Cylinder SI Engine Ignited by a LASER System

2019 ◽  
Vol 112 ◽  
pp. 01009
Author(s):  
Bogdan George Done ◽  
Ion Copae
Keyword(s):  
New Technologies ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Laser Medium ◽  
Si Engine ◽  
Engine Operation ◽  
Single Cylinder ◽  
Spark Plug ◽  
Octane Rating ◽  
Laser Spark

At this time, the severe legislation regarding the level limits of the waste and exhaust gases released by thermal engines and also the necessity of engines efficiency improvement boost the engine research domain to bring in front the use of new technologies that can be used to control the in-cylinder combustion process. Now, the new technologies is represented by LASER spark plug systems which can be successfully used at petrol engines. LASER spark plug technology can have many advantages for engine operation control, an ignition system that could provide improved combustion is the one using plasma generation and a Q-switched LASER that results in pulses with high MW power. The LASER spark plug device used in the current research was a LASER medium Nd:YAG/Cr4+:YAG ceramic structure made up of a 8.0-mm long, 1.0-at.% Nd:YAG ceramic, optically-bonded to a Cr4+:YAG c. It was developed and constructed similar to classical spark plug and could be assembled on a CFR Octane Rating Unit Engine as well as on a Dacia Single Cylinder SI Engine which led to several results among which: influences on in-cylinder pressure, combustion and pollutant emissions.

scholarly journals Optical Investigation of a Partial Fuel Stratification Strategy to Stabilize Overall Lean Operation of a DISI Engine Fueled with Gasoline and E30

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 396
Author(s):  
Cinzia Tornatore ◽  
Magnus Sjöberg
Keyword(s):  
Volume Fraction ◽  
Direct Injection ◽  
Combustion Process ◽  
Pilot Injection ◽  
Optical Investigation ◽  
Flame Kernel ◽  
Lean Combustion ◽  
Fuel Stratification ◽  
Spark Plug ◽  
Initial Flame

This paper offers new insights into a partial fuel stratification (PFS) combustion strategy that has proven to be effective at stabilizing overall lean combustion in direct injection spark ignition engines. To this aim, high spatial and temporal resolution optical diagnostics were applied in an optically accessible engine working in PFS mode for two fuels and two different durations of pilot injection at the time of spark: 210 µs and 330 µs for E30 (gasoline blended with ethanol by 30% volume fraction) and gasoline, respectively. In both conditions, early injections during the intake stroke were used to generate a well-mixed lean background. The results were compared to rich, stoichiometric and lean well-mixed combustion with different spark timings. In the PFS combustion process, it was possible to detect a non-spherical and highly wrinkled blue flame, coupled with yellow diffusive flames due to the combustion of rich zones near the spark plug. The initial flame spread for both PFS cases was faster compared to any of the well-mixed cases (lean, stoichiometric and rich), suggesting that the flame propagation for PFS is enhanced by both enrichment and enhanced local turbulence caused by the pilot injection. Different spray evolutions for the two pilot injection durations were found to strongly influence the flame kernel inception and propagation. PFS with pilot durations of 210 µs and 330 µs showed some differences in terms of shapes of the flame front and in terms of extension of diffusive flames. Yet, both cases were highly repeatable.

Study of High Load Operation Limit Expansion for Gasoline Compression Ignition Engines

2006 ◽  
Vol 128 (2) ◽  
pp. 377-387 ◽  
Author(s):  
Koudai Yoshizawa ◽  
Atsushi Teraji ◽  
Hiroshi Miyakubo ◽  
Koichi Yamaguchi ◽  
Tomonori Urushihara
Keyword(s):  
Fuel Injection ◽  
Control Method ◽  
Combustion Process ◽  
High Load ◽  
Compression Ignition ◽  
Ignition Timing ◽  
Timing Control ◽  
Load Range ◽  
Compression Ignition Engines ◽  
Spark Plug

In this research, combustion characteristics of gasoline compression ignition engines have been analyzed numerically and experimentally with the aim of expanding the high load operation limit. The mechanism limiting high load operation under homogeneous charge compression ignition (HCCI) combustion was clarified. It was confirmed that retarding the combustion timing from top dead center (TDC) is an effective way to prevent knocking. However, with retarded combustion, combustion timing is substantially influenced by cycle-to-cycle variation of in-cylinder conditions. Therefore, an ignition timing control method is required to achieve stable retarded combustion. Using numerical analysis, it was found that ignition timing control could be achieved by creating a fuel-rich zone at the center of the cylinder. The fuel-rich zone works as an ignition source to ignite the surrounding fuel-lean zone. In this way, combustion consists of two separate auto-ignitions and is thus called two-step combustion. In the simulation, the high load operation limit was expanded using two-step combustion. An engine system identical to a direct-injection gasoline (DIG) engine was then used to validate two-step combustion experimentally. An air-fuel distribution was created by splitting fuel injection into first and second injections. The spark plug was used to ignite the first combustion. This combustion process might better be called spark-ignited compression ignition combustion (SI-CI combustion). Using the spark plug, stable two-step combustion was achieved, thereby validating a means of expanding the operation limit of gasoline compression ignition engines toward a higher load range.

Effects of H2 Addition to CNG Blends on Cycle-to-Cycle and Cylinder-to-Cylinder Combustion Variation in an SI Engine

2012 ◽  
Author(s):  
Mirko Baratta ◽  
Stefano d’Ambrosio ◽  
Daniela Misul ◽  
Ezio Spessa
Keyword(s):  
Diagnostic Tool ◽  
Combustion Process ◽  
Experimental Tests ◽  
Test Point ◽  
Pollutant Emissions ◽  
Engine Operation ◽  
Pressure Transducers ◽  
Rate Analysis ◽  
Spark Plug ◽  
Wide Range

An experimental investigation and a burning-rate analysis have been performed on a production 1.4 liter CNG (compressed natural gas) engine fueled with methane-hydrogen blends. The engine features a pent-roof combustion chamber, four valves per cylinder and a centrally located spark plug. The experimental tests have been carried out in order to quantify the cycle-to-cycle and the cylinder-to-cylinder combustion variation. Therefore, the engine has been equipped with four dedicated piezoelectric pressure transducers placed on each cylinder and located by the spark plug. At each test point, in-cylinder pressure, fuel consumption, induced air mass flow rate, pressure and temperature at different locations on the engine intake and exhaust systems as well as ‘engine-out’ pollutant emissions have been measured. The signals correlated to the engine operation have been acquired by means of a National Instruments PXI-DAQ system and a home developed software. The acquired data have then been processed through a combustion diagnostic tool resulting from the integration of an original multizone thermodynamic model with a CAD procedure for the evaluation of the burned-gas front geometry. The diagnostic tool allows the burning velocities to be computed. The tests have been performed over a wide range of engine speeds, loads and relative air-fuel ratios (up to the lean operation). For stoichiometric operation, the addition of hydrogen to CNG has produced a bsfc reduction ranging between 2 to 7% and a bsTHC decrease up to the 40%. These benefits have appeared to be even higher for lean mixtures. Moreover, hydrogen has shown to significantly enhance the combustion process, thus leading to a sensibly lower cycle-to-cycle variability. As a matter of fact, hydrogen addition has generally resulted into extended operation up to RAFR = 1.8. Still, a discrepancy in the abovementioned conclusions was observed depending on the engine cylinder considered.

A Control-Oriented Reaction-Based SI Engine Combustion Model

2018 ◽  
Author(s):  
Ruixue C. Li ◽  
Guoming G. Zhu
Keyword(s):  
Chemical Reaction ◽  
Mass Fraction ◽  
Combustion Process ◽  
Combustion Model ◽  
Spark Ignition Engines ◽  
Si Engine ◽  
Chemical Reaction Mechanism ◽  
Engine Combustion ◽  
Rate Of Heat Release ◽  
Mass And Heat Transfer

This paper proposes a control-oriented chemical reaction-based two-zone combustion model designed to accurately describe the combustion process and thermal performance for spark-ignition engines. The combustion chamber is assumed to be divided into two zones: reaction and unburned zones, where the chemical reaction takes place in the reaction zone and the unburned zone contains all the unburned mixture. In contrast to the empirical pre-determined Wiebe-function-based combustion model, an ideal two-step chemical reaction mechanism is used to reliably model the detailed combustion process such as mass-fraction-burned (MFB) and rate of heat release. The interaction between two zones includes mass and heat transfer at the zone interface to have a smooth combustion process. This control-oriented model is extensively calibrated based on the experimental data to demonstrate its capability of predicting the combustion process and thermodynamic states of the in-cylinder mixture.

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