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.

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.

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.

Characteristics of New Ignition Systems to Improve Engine Performance

1967 ◽  
Vol 182 (1) ◽  
pp. 15-24 ◽  
Author(s):  
By R. C. Teasel ◽  
R. D. Miller
Keyword(s):  
United States ◽  
Engine Performance ◽  
Spark Ignition ◽  
Spark Discharge ◽  
Spark Ignition Engine ◽  
Development Effort ◽  
Engine Operation ◽  
Discharge Characteristics ◽  
Ignition System ◽  
Spark Plug

The increasing use of spark ignition engines throughout the world has confronted the engine designer with new problems such as air pollution, world-wide temperature extremes, as well as legislative, economic, and human considerations. To meet these situations and improve the competitive position of the spark ignition engine requires considerable research and development effort. This paper reports on work conducted by Champion Spark Plug Company in attempting to evaluate the potential contribution that ignition system and spark plug designs can make towards improving spark ignition engine operation. Almost all the work reported here covers investigations in current large displacement United States passenger car engines. The three main characteristics of the overall ignition systems that are investigated are (1) the available output voltage characteristics of the ignition systems; (2) the effect of the ignition system spark discharge characteristics on engine performance; and (3) the effect of several spark plug design features on engine performance. This investigation shows that the inter-relationship of the ignition system spark discharge characteristics and the spark plug design requires that the overall evaluation must consider the dependence of both items. It also suggests that significant improvements can result in other United States and European engines, through the careful evaluation of ignition system and spark plug designs. The results of this work indicate that a fast rise time, short arc duration system results in reduced spark plug gap growth and better resistance to spark plug fouling. However, the arc duration must not be shorter than a minimum value, or a loss in engine performance may result. High output systems are desirable as they provide a higher voltage reserve to provide longer spark plug life, but the higher voltages that occur with the larger spark plug gaps can stress other ignition system components. The spark plug designs which incorporate a projection of the spark plug gap result in better performance in the engines tested, and possibly even reduce exhaust emissions. Certainly other features which engine manufacturers must consider, which are not discussed in detail here, are costs, durability, and maintenance of the new systems. At least one other important related problem is that of interference.

Combustion and Emission Characteristics of Gasoline Blended With Alcohols

2009 ◽  
Author(s):  
Shenghua Liu ◽  
Yi Li ◽  
Guangle Li ◽  
Lei Chi
Keyword(s):  
Ambient Temperature ◽  
Alternative Fuels ◽  
Spark Ignition ◽  
Flame Speed ◽  
Emission Characteristics ◽  
Spark Ignition Engines ◽  
Increase Oxygen Content ◽  
Cold Starting ◽  
Engine Combustion ◽  
Different Temperatures

Methanol and ethanol are known as potential alcohol alternative fuels for spark ignition Engines, which can be blended with gasoline to increase oxygen content and to decrease emissions. Six kinds of fuels were prepared, which were commercial 93#gasoline, M10, M20, M30, E10 and E20. With a constant volume bomb, flame propagation speeds were studied under different temperatures, exhaust dilution and air fuel ratios. The flame radiuses were used to calculate the flame speed. The results indicate that methanol can increase flame speed no matter with or without exhaust dilution. At the ambient temperature of 5°C and 15°C, engine cold starting tests prove that methanol can improve engine combustion and lower HC and CO emissions during the first 200 seconds, while ethanol has little effects at the same conditions.

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