A New Approach for Ignition Timing Correction in Spark Ignition Engines Based on Cylinder Tendency to Surface Ignition

2016 ◽  
Vol 819 ◽  
pp. 272-276 ◽  
Author(s):  
Ali Ghanaati ◽  
Mohd Farid Muhamad Said ◽  
Intan Zaurah Mat Darus ◽  
Amin Mahmoudzadeh Andwari
Keyword(s):  
Spark Ignition ◽  
Combustion Stability ◽  
Spark Ignition Engines ◽  
Gas Temperature ◽  
New Approach ◽  
Surface Ignition ◽  
Spark Plug ◽  
Engine Combustion ◽  
Si Engines ◽  
Exhaust Gas Temperature

The performance of Spark Ignition (SI) engines in terms of thermal efficiency can be restricted by knock. Although it is common for all SI engines to exhibit knock from compressed end-gas, knocks from surface ignition remains a more serious problem due to its effect on combustion stability and its obscurity to detect. This paper focuses on predicting the occurrence of knocks from surface ignition by monitoring exhaust gas temperature (EGT). EGT measured during an engine cycle without the spark plug firing. Therefore, EGT rises illustrated any combustion made by surface ignition. Modelling and simulation of a one-dimensional engine combustion done by using GT-Power. The new approach reduces the complexity as EGT monitoring does not require high computational demands, and the EGT signals are robust to noise. The method is validated against a variety of fuel properties and across engine conditions. A new approach is proposed as a measure to predict and detect the knock events.

scholarly journals A Fast CFD-Based Methodology for Determining the Cyclic Variability and Its Effects on Performance and Emissions of Spark-Ignition Engines

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4131
Author(s):  
George M. Kosmadakis ◽  
Constantine D. Rakopoulos
Keyword(s):  
Spark Ignition ◽  
Pollutant Emissions ◽  
Computational Time ◽  
Spark Ignition Engines ◽  
Cyclic Variability ◽  
Indicated Mean Effective Pressure ◽  
Spark Plug ◽  
Performance And Emissions ◽  
Si Engines ◽  
Cyclic Variations

A methodology for determining the cyclic variability in spark-ignition (SI) engines has been developed recently, with the use of an in-house computational fluid dynamics (CFD) code. The simulation of a large number of engine cycles is required for the coefficient of variation (COV) of the indicated mean effective pressure (IMEP) to converge, usually more than 50 cycles. This is valid for any CFD methodology applied for this kind of simulation activity. In order to reduce the total computational time, but without reducing the accuracy of the calculations, the methodology is expanded here by simulating just five representative cycles and calculating their main parameters of concern, such as the IMEP, peak pressure, and NO and CO emissions. A regression analysis then follows for producing fitted correlations for each parameter as a function of the key variable that affects cyclic variability as has been identified by the authors so far, namely, the relative location of the local turbulent eddy with the spark plug. The application of these fitted correlations for a large number of engine cycles then leads to a fast estimation of the key parameters. This methodology is applied here for a methane-fueled SI engine, while future activities will examine cyclic variations in SI engines when fueled with different fuels and their mixtures, such as methane/hydrogen blends, and their associated pollutant emissions.

A Comprehensive Ignition System Model for Spark Ignition Engines

2018 ◽  
Author(s):  
Haiwen Ge ◽  
Peng Zhao
Keyword(s):  
Spark Ignition ◽  
System Model ◽  
Spark Ignition Engines ◽  
Working Mechanism ◽  
Local Flow ◽  
Ignition System ◽  
Spark Plug ◽  
Engine Combustion ◽  
Combustion Simulation ◽  
Air Column

In the present paper, a comprehensive ignition system model (VTF ignition model) accounting for the practical module and working mechanism of a spark plug was developed, aiming to provide enhanced capability for the 3D combustion simulation of spark ignition engines. In this model, an electrical circuitry model is used to represent the ignition coil, spark plug, and air column. The air column is represented by a set of Lagrangian particles that move with the local flow field. Flame propagation is directly calculated using SAGE model with a reduced isooctane reaction mechanism. The new ignition system model is further implemented into CONVERGE through user defined functions and is verified by comparing with the conventional DPIK model. It is found that the VTF ignition model predicts slower combustion than the DPIK model, mainly due to more realistic energy deposit method and energy discharging rate. Furthermore, the VTF model also has the capability of predicting the arc motion and restrike phenomena associated with spark ignition processes. It is expected that with more validation with experiments, the new VTF model has the great potential to better serve the needs of engine combustion simulation.

scholarly journals Numerical investigations on hydrogen-enhanced combustion in ultra-lean gasoline spark-ignition engines

2019 ◽  
pp. 146808741987068 ◽  
Author(s):  
Nicolas Iafrate ◽  
Mickael Matrat ◽  
Jean-Marc Zaccardi
Keyword(s):  
Ignition Delay ◽  
Combustion Process ◽  
Spark Ignition ◽  
Combustion Stability ◽  
Spark Ignition Engines ◽  
Numerical Investigations ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Delay Times ◽  
Combustion Speed

Performance of lean-burn gasoline spark-ignition engines can be enhanced through hydrogen supplementation. Thanks to its physicochemical properties, hydrogen supports the flame propagation and extends the dilution limits with improved combustion stability. These interesting features usually result in decreased emissions and improved efficiencies. This article aims at demonstrating how hydrogen can support the combustion process with a modern combustion system optimized for high dilution resistance and efficiency. To achieve this, chemical kinetics calculations are first performed in order to quantify the impacts of hydrogen addition on the laminar flame speed and on the auto-ignition delay times of air/gasoline mixtures. These data are then implemented in the extended coherent flame model and tabulated kinetics of ignition combustion models in a specifically updated version of the CONVERGE code. Three-dimensional computational fluid dynamics engine calculations are performed at λ = 2 with 3% v/v of hydrogen for two operating points. At low load, numerical investigations show that hydrogen enhances the maximal combustion speed and the flame growth just after the spark which is a critical aspect of combustion with diluted mixtures. The flame front propagation is also more isotropic when supported with hydrogen. At mid load, hydrogen improves the combustion speed and also extends the auto-ignition delay times resulting in a better knocking resistance. A maximal indicated efficiency of 48.5% can thus be reached at λ = 2 thanks to an optimal combustion timing.

Modifications to Quasi-Dimensional Burning Model of Spark Ignition Engines

2009 ◽  
Author(s):  
M. R. Modarres Razavi ◽  
A. Hosseini ◽  
M. Dehnavi
Keyword(s):  
Heat Transfer ◽  
Combustion Chamber ◽  
Numerical Solution ◽  
Taylor Expansion ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Spark Ignition Engines ◽  
Algebraic Functions ◽  
Spark Plug ◽  
Burning Model

The way in which position of spark plug affects combustion in a spark ignition engine can be analyzed by using two-zone burning model. The purpose of this paper is to extract correlations to simulate the geometric interaction between the propagating flame and the general cylindrical combustion chamber. Eight different cases were recognized. Appropriate equations to calculate the flame area (Af), the burned and the unburned volume (Vb & Vu) and the heat transfer areas related to the burned and unburned regions were derived and presented for each case using Taylor expansion in order to replace numerical solution with trigonometric algebraic functions.

Emissions Level Approximation at Cold Start for Spark Ignition Engine Vehicles

2014 ◽  
Vol 555 ◽  
pp. 375-384 ◽  
Author(s):  
Stelian Tarulescu ◽  
Adrian Soica
Keyword(s):  
Cold Start ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Estimation Methods ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Mathematical Approximation ◽  
Exhaust Gas Temperature ◽  
The Mathematical Model ◽  
Polynomial Regressions

This paper present a study regarding the emissions produced at the engine cold start. Also, the paper presents a brief survey of current extra emissions estimation methods. The main goal of this work is to describe the relative cold start extra emissions as a function of exhaust gas temperature. Experimental research has been done for a light vehicle, Dacia Sandero, equipped with a 1390 cm3 Renault spark ignition engine (Power = 55 kW at 5500 rpm). There were been made several tests, in different temperature conditions, in the could season, using a portable analyzer, GA-21 plus (produced by Madur Austria). The parameters measured with the analyzer and used in the analysis are: CO, NO, NOx and SO2. It was concluded that the highest pollutants values ​​are recorded until the point when the catalyst comes into operation (when the gas temperature entering the catalyst is approx. 200 oC) and exhaust gas temperature is 40-50 oC. In order to accomplish a mathematical approximation of CO, NO and SO2 in function of exhaust gas temperature, logarithmic approximations and polynomial regressions were used. The curves resulted from the mathematical model can be used to approximate the level of CO, NO and SO2, for similar vehicles.

scholarly journals Correlation of Performance, Exhaust Gas Temperature and Speed of a Spark Ignition Engine Using Kiva4

2021 ◽  
Vol 09 (08) ◽  
pp. 53-78
Author(s):  
Joseph Lungu ◽  
Lennox Siwale ◽  
Rudolph Joe Kashinga ◽  
Shadreck Chama ◽  
Akos Bereczky
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Exhaust Gas Temperature

scholarly journals Effect of Sisal Nanoparticles on Single Cylinder Spark Ignition Engine Combustion

2020 ◽  
Vol 8 (6) ◽  
pp. 1027-1032
Keyword(s):  
Flame Propagation ◽  
Combustion Process ◽  
Fuel Mixture ◽  
Spark Ignition ◽  
Combustion Efficiency ◽  
Spark Ignition Engine ◽  
Single Cylinder ◽  
Engine Combustion ◽  
Si Engines ◽  
Propagation Velocities

Turbulence is an important parameter to be considered for effective combustion inside a cylinder. Heat transfer inside the cylinder affects the combustion process. Insufficient turbulence leads to incomplete combustion, resulting in pollution. Effective flame propagation leads to higher combustion rates in SI engines which in turn requires enough turbulence. Effective combustion efficiency can be achieved through higher flame propagation velocities. In the present work an attempt has been made to enhance the turbulence inside the cylinder of a single cylinder spark ignition engine by injecting solid nanoparticles into the air fuel mixture.

scholarly journals RESEARCH ON CHARACTERISTICS OF TURBO JET ENGINE COMBUSTION CHAMBER

Aviation ◽  
2021 ◽  
Vol 25 (1) ◽  
pp. 65-72
Author(s):  
Andrius Dubovas ◽  
Domantas Bručas
Keyword(s):  
Combustion Chamber ◽  
Computer Simulations ◽  
Operating Parameters ◽  
Exhaust Gas ◽  
Jet Engines ◽  
Gas Temperature ◽  
Jet Engine ◽  
Engine Combustion ◽  
Exhaust Gas Temperature ◽  
Combustion Mixture

The characteristics of the combustion chamber of turbo jet engine with various parameters are examined in this article. The scientific works of other authors analyzing operating parameters of the jet engines were reviewed. Their recommendations were considered. Computer simulations of the combustion chamber were performed using different combustion reactions. The exhaust gas temperature and its dependence on the combustion mixture were determined. A practical study was also carried out, during which the experimental exhaust gas temperature was measured, and the trends of temperature change were determined. After analyzing both theoretical and practical results, the conclusions are presented.

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