The Effect of Spark Plug Electrode Geometry on Combustion Rates in a High Performance Automotive Engine

2013 ◽  
Author(s):  
Jeremy J. Worm ◽  
Jim McFarland ◽  
Forrest Jehlik ◽  
Paul W. Dice ◽  
Scott A. Miers
Keyword(s):  
High Performance ◽  
Electrode Geometry ◽  
Ignition Timing ◽  
Combustion Analysis ◽  
Transient Conditions ◽  
Automotive Engine ◽  
Automotive Engines ◽  
Spark Plug ◽  
Test Engine ◽  
Burn Rate

Spark plugs utilizing a J-wire electrode are standard in most automotive engines and have been for decades. However, innumerable alternative spark plug designs have been introduced. This paper examines the potential benefit of one particular alternative electrode geometry in a high-performance automotive engine. The alternative spark plug that is investigated is a commercially available aftermarket unit. The testing included detailed analysis of both brake and indicated parameters including MEP and burn rates. Testing was conducted under both steady state and transient conditions, and encompassed multiple induction systems and test fuels including E85. The test engine was a commercially available high performance aftermarket engine assembly intended for motorsports. This paper includes the optimal settings for ignition timing and lambda and the process by which those values were determined. The combustion analysis shows the alternative spark plug electrode resulted in an increased early burn rate, which in turn lead to an overall advancing of the combustion phasing. To better decouple combustion phasing effects from test to test variation on brake output parameters, an empirical model is developed and exercised. The model describes the expected change in brake output resulting from the shift in combustion phasing induced by the alternative spark plug geometry.

A hybrid method of tests coupled with simulations used to detect the working processes of an automotive engine from cycle to cycle in transient conditions

2017 ◽  
Vol 231 (13) ◽  
pp. 1766-1779 ◽  
Author(s):  
Jianqin Fu ◽  
Zhipeng Yuan ◽  
Jingping Liu ◽  
Feng Zhou ◽  
Shuqian Wang ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
High Speed ◽  
Engine Performance ◽  
Gas Pressure ◽  
Ignition Timing ◽  
Actual Performance ◽  
Transient Conditions ◽  
Automotive Engine ◽  
The Difference ◽  
Working Processes

To improve the actual performance of an automotive engine, an approach consisting of dynamic signal measurements coupled with gas dynamics–thermodynamics process simulations is proposed; this is used to detect the working processes of an automotive engine from cycle to cycle in transient conditions. Based on the working principles and the mathematical models of the proposed detection method, corresponding software was developed, and the reliability of this approach was validated on an automotive engine. Automotive road tests were conducted, and various transient parameters of the engine were successfully detected from cycle to cycle by using the developed software. On this basis, the variations in the influencing factors of and the interactions between various engine parameters were analysed. The results showed that the ignition timing has a strong effect on the indicated thermal efficiency. Where there is an unnecessary delay in the ignition timing, there is a decrease in the indicated thermal efficiency. The pumping mean effective pressure is approximately equal to the difference between the exhaust gas pressure and the intake gas pressure for a low to medium load, but it is much higher than the pressure difference and undergoes great fluctuations in the high-speed and high-load operating regions. Both the presented approach and the research results are significant for improving the engine performance in transient conditions.

Signal processing algorithms for multichannel integrated engines complex diagnostics for automobiles and tractors

Trudy NAMI ◽  
2021 ◽  
pp. 6-15
Author(s):  
V. E. Tarasenko ◽  
O. Ch. Rolich ◽  
O. A. Yakubovich ◽  
A. V. Kozlov
Keyword(s):  
Real Time ◽  
High Performance ◽  
Residual Life ◽  
Technical Condition ◽  
Integrated System ◽  
Automotive Engine ◽  
Automotive Engines ◽  
Signal Processing Algorithms ◽  
Qualitative Determination

Introduction (problem statement and relevance). The technical state of machines undergoes changes during their life cycle. The qualitative determination of the technical condition of components, assemblies and systems of engines requires not only the application of modern control methods that provide reliable results, but also the use of high-performance specialized diagnostic equipment for the timely detection of faults to increase the reliability and service life of machines.The purpose of the study was to substantiate the architecture of an integrated system of vibroacoustic and thermal diagnostics, which would make it possible to assess the residual life of systems, assemblies and mechanisms of diesel engines in real time.Methodology and research methods. The modern methods of collection and computer processing of signals from various types of sensors, as well as wavelet functions and digital image processing were used in the study.Scientifi c novelty and results. Algorithms for calculating and processing the analytical ensemble (including scaleograms and histograms) of the data fl ow have been developed and used in an integrated system of complex diagnostics to identify defects in automotive engines and detect the moments of their origin.Practical signifi cance. The proposed algorithms made it possible to diagnose malfunctions and calculate the residual resource of automotive engine units in real time, display the dynamics of signal changes on the display, process user requests and form a protocol for changing the diesel state picture during its operation.

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.

CFD Methodology for the Simulation of Mixture Formation of High Performance PFI Engines

2011 ◽  
Author(s):  
Claudio Forte ◽  
Gian Marco Bianchi ◽  
Enrico Corti ◽  
Gaspare Argento ◽  
Stefano Fantoni
Keyword(s):  
High Performance ◽  
Experimental Tests ◽  
Critical Issue ◽  
Spark Ignition Engines ◽  
Mixture Formation ◽  
Injection Process ◽  
Cfd Models ◽  
Cycle Simulation ◽  
Spark Plug ◽  
The Stability

Mixture composition strongly influences the stability of combustion of spark ignition engines. The control of air to fuel ratio at ignition is a critical issue for high performance engines: due to the low stroke-to-bore ratio the maximum power is reached at very high regimes, letting little time to the fuel to evaporate and mix with air. The aim of this work is to present a CFD methodology for the evaluation of mixture formation applied to a Ducati high performance engine. The phenomena involved in the process are highly heterogeneous, and particular care must be taken to the choice of CFD models and their validation. In the present work all the main models involved in the simulations are validated against experimental tests available in the literature, selected based on the similarity of physical conditions with those of the engine configuration under analysis. The multi-cycle simulation methodology here presented reveals to be a useful tool for the evaluation of the mixture quality around the spark plug at ignition, allowing a parametric analysis of the effects of the injection process on engine output.

scholarly journals PRELIMINARY STUDY ON COMBUSTION AND OVERALL PARAMETERS OF SYNGAS FUEL MIXTURES FOR SPARK IGNITION COMBUSTION ENGINE

2017 ◽  
Vol 57 (1) ◽  
pp. 38-48 ◽  
Author(s):  
Rastislav Toman ◽  
Marián Polóni ◽  
Andrej Chríbik
Keyword(s):  
Combustion Engine ◽  
Spark Ignition ◽  
Full Scale ◽  
Inert Gases ◽  
Combustion Model ◽  
Closed Volume ◽  
Combustion Analysis ◽  
Gaseous Fuels ◽  
Fuel Mixtures ◽  
Burn Rate

This paper presents a numerical study on a group of alternative gaseous fuels – syngases, and their use in the spark-ignition internal combustion engine Lombardini LGW 702. These syngas fuel mixtures consist mainly of hydrogen and carbon monoxide, together with inert gases. An understanding of the impact of the syngas composition on the nature of the combustion process is essential for the improvement of the thermal efficiency of syngas-fuelled engines. The paper focuses on six different syngas mixtures with natural gas as a reference. The introduction of the paper goes through some recent trends in the field of the alternative gaseous fuels, followed by a discussion of the objectives of our work, together with the selection of mixtures. Important part of the paper is dedicated to the experimental and above all to the numerical methods. Two different simulation models are showcased: the single-cylinder ‘closed-volume’ combustion analysis model and the full-scale LGW 702 model; all prepared and tuned with the GT-Power software. Steady-state engine measurements are followed by the combustion analysis, which is undertaken to obtain the burn rate profiles. The burn rate profiles, in the form of the Vibe formula, are than inserted into the in-house developed empirical combustion model based on Csallner-Woschni recalculation formulas. Its development is described in the scope as well. The full-scale LGW 702 simulation model, together with this empirical combustion model, is used for the evaluation of engine overall performance parameters, running on gaseous fuel mixtures. The analysis was carried out only under the conditions of engine on full load and the stoichiometric mixture.

Optimization of the Charge Motion in Internal Combustion Engines Driven by Sewage Gas for CHP-Units

2017 ◽  
Author(s):  
Lucas Konstantinoff ◽  
Lukas Möltner ◽  
Martin Pillei ◽  
Thomas Steiner ◽  
Thomas Dornauer ◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Engine Performance ◽  
Internal Combustion ◽  
Optical Methods ◽  
Combustion Engines ◽  
Charge Motion ◽  
Combustion Analysis ◽  
Valve Seat ◽  
Test Engine ◽  
Indication System

In this study, the influence of the charge motion on the internal combustion in a spark ignition sewage gas-driven engine (150 kW) for combined heat and power units was investigated. For this purpose, the geometry of the combustion chamber in the immediate vicinity to the inlet valve seats was modified. The geometrical modification measures were conducted iteratively by integrative determination of the swirl motion on a flow bench, by laser-optical methods and consecutively by combustion analysis on a test engine. Two different versions of cylinder heads were characterized by dimensionless flow and swirl numbers prior to testing their on-engine performance. Combustion analysis was conducted with a cylinder pressure indication system for partial and full load, meeting the mandatory NOx limit of 500 mg m−3. Subsuming the flow bench results, the new valve seat design has a significant enhancing impact on the swirl motion but it also leads to disadvantages concerning the volumetric efficiency. A comparative consideration of the combustion rate delivers that the increased swirl motion results in a faster combustion, hence in a higher efficiency. In summary, the geometrical modifications close to the valve seat result in increased turbulence intensity. It was proven that this intensification raises the ratio of efficiency by 1.6%.

Optimization of Electrode Arrangement and Prechamber Geometry of Passive Prechamber Spark Plugs for Turbocharged Gas Engines With High Charge Motion

2018 ◽  
Author(s):  
Dominik Mairegger ◽  
Rüdiger Herdin ◽  
Lucas Konstantinoff ◽  
Lukas Möltner
Keyword(s):  
Operating Conditions ◽  
Charge Motion ◽  
Combustion Analysis ◽  
Combustion Chambers ◽  
Engine Efficiency ◽  
Electrode Arrangement ◽  
Spark Plug ◽  
Brake Mean Effective Pressure ◽  
Exhaust Gas Emissions

Turbocharged gas engines for combined heat and power units are optimized to increase efficiency while observing and maintaining legitimate exhaust gas emissions. In order to do so, the charge motion is raised. This study investigates the influence of passive prechamber spark plugs in high turbulent combustion chambers. The subjects of investigation are two different gas engine types, one of them running on sewage gas the other one on biogas. The occurring charge motions initiated by the cylinder heads are measured by integrative determination of swirl motion on a flow bench. In addition, three different passive prechamber spark plugs are characterized by a combustion analysis. Each of the three spark plugs comes with a different electrode or prechamber geometry. The resulting combustion and operating conditions are compared while the equal brake mean effective pressure and constant NOx-emissions are sustained. The results of the combustion analysis show a rising influence of the spark plug with increasing air-to-fuel-ratio induced by charge motion. Furthermore, clear differences between the spark plugs are determined: electrode arrangement and prechamber geometry help to influence lean misfire limits, engine smoothness, start behavior and ignition delay. The results indicate the capability of spark plugs to increase lifetime and engine efficiency.

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