scholarly journals Relations between ion signal and flame propagation in cylinder of a rapid compression machine

2019 ◽  
Vol 179 (4) ◽  
pp. 264-268
Author(s):  
Łukasz FIEDKIEWICZ ◽  
Ireneusz PIELECHA
Keyword(s):  
Combustion Engine ◽  
Combustion Process ◽  
Coefficient Of Determination ◽  
Rapid Compression Machine ◽  
Process Diagnosis ◽  
Gaseous Fuels ◽  
Ionization Signal ◽  
Flame Development ◽  
Combustion Phase ◽  
Rapid Compression

Internal combustion engine diagnostics using traditional methods of cylinder pressure signal processing limits the amount of information available about the combustion process. It is necessary to conduct research in order to obtain more precise information – increasing the combustion process diagnosis potential. One such suggestion is the use of an ionization signal and an attempt to link it to the flame development during combustion of gaseous fuels. The article attempts to identify such a relationship using a rapid compression machine due to optical access it provides to the combustion chamber. As a result of the research, the relationships between the ionization voltage (chemical and thermal) of the first combustion phase and the corresponding flame development rates were determined. A relatively high coefficient of determination value was obtained for both relations, which indicates the possibility of obtaining diagnostic information about the combustion process from the ionization signal.

Review of the Investigation of Fuel-Air Premixing and Combustion Process Using Rapid Compression Machine and Direct Visualization System

2013 ◽  
Vol 465-466 ◽  
pp. 265-269 ◽  
Author(s):  
Mohamad Jaat ◽  
Amir Khalid ◽  
Bukhari Manshoor ◽  
Siti Mariam Basharie ◽  
Him Ramsy
Keyword(s):  
High Speed ◽  
Combustion Engine ◽  
Early Stage ◽  
Combustion Process ◽  
Injection Pressure ◽  
Rapid Compression Machine ◽  
Mixture Formation ◽  
Visualization System ◽  
Optical Visualization ◽  
Rapid Compression

s :This paper reviews of some applications of optical visualization system to compute the fuel-air mixing process during early stage of mixture formation and late injection in Diesel Combustion Engine. This review has shown that the mixture formation is controlled by the characteristics of the injection systems, the nature of the air swirl and turbulence in thecylinder, and spray characteristics. Few experimental works have been investigated and found that the effects of injection pressure and swirl ratio have a great effect on the mixture formation then affects to the flame development and combustion characteristics.This paper presents the significance of spray and combustion study with optical techniques access rapid compression machine that have been reported by previous researchers. Experimental results are presentedin order to provide in depth knowledge as assistance to readers interested in this research area. Analysis of flame motion and flame intensity in the combustion chamber was performed using high speed direct photographs and image analysis technique. The application of these methods to the investigation of diesel sprays highlights mechanisms which provide a better understanding of spray and combustion characteristics.

scholarly journals Combustion Thermodynamics of Ethanol, n-Heptane, and n-Butanol in a Rapid Compression Machine with a Dual Direct Injection (DDI) Supply System

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2729
Author(s):  
Ireneusz Pielecha ◽  
Sławomir Wierzbicki ◽  
Maciej Sidorowicz ◽  
Dariusz Pietras
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Injection System ◽  
Rapid Compression Machine ◽  
Process Indicators ◽  
Rapid Compression

The development of internal combustion engines involves various new solutions, one of which is the use of dual-fuel systems. The diversity of technological solutions being developed determines the efficiency of such systems, as well as the possibility of reducing the emission of carbon dioxide and exhaust components into the atmosphere. An innovative double direct injection system was used as a method for forming a mixture in the combustion chamber. The tests were carried out with the use of gasoline, ethanol, n-heptane, and n-butanol during combustion in a model test engine—the rapid compression machine (RCM). The analyzed combustion process indicators included the cylinder pressure, pressure increase rate, heat release rate, and heat release value. Optical tests of the combustion process made it possible to analyze the flame development in the observed area of the combustion chamber. The conducted research and analyses resulted in the observation that it is possible to control the excess air ratio in the direct vicinity of the spark plug just before ignition. Such possibilities occur as a result of the properties of the injected fuels, which include different amounts of air required for their stoichiometric combustion. The studies of the combustion process have shown that the combustible mixtures consisting of gasoline with another fuel are characterized by greater combustion efficiency than the mixtures composed of only a single fuel type, and that the influence of the type of fuel used is significant for the combustion process and its indicator values.

Analysis of Mixture Formation and Flame Development of Diesel Combustion Using a Rapid Compression Machine and Optical Visualization Technique

2013 ◽  
Vol 315 ◽  
pp. 293-298 ◽  
Author(s):  
Amir Khalid ◽  
Bukhari Manshoor
Keyword(s):  
Fuel Injection ◽  
Injection Pressure ◽  
Exhaust Emissions ◽  
Combustion Characteristics ◽  
Diesel Combustion ◽  
Rapid Compression Machine ◽  
Mixture Formation ◽  
Optical Visualization ◽  
Flame Development ◽  
Rapid Compression

Mixture formation plays as a key element on burning process that strongly affects the exhaust emissions such as nitrogen oxide (NOx) and Particulate Matter (PM). The reductions of emissions can be achieved with improvement throughout the mixing of fuel and air behavior. Measurements were made in an optically-accessible rapid compression machine (RCM) with intended to simulate the actual diesel combustion related phenomena. The diesel combustion was simulated with the RCM which is equipped with the Denso single-shot common-rail fuel injection system, capable of a maximum injection pressure up to 160MPa. Diesel engine compression process could be reproduced within the wide range of ambient temperature, ambient density, swirl velocity, equivalence ratio and fuel injection pressure. The mixture formation and combustion images were captured by the high speed camera. Analysis of combustion characteristics and observations of optical visualization of images reveal that the mixture formation exhibit influences to the ignition process and flame development. Therefore, the examination of the first stage of mixture formation is very important consideration due to the fuel-air premixing process linked with the combustion characteristics. Furthermore, the observation of a systematic control of mixture formation with experimental apparatus enables us to achieve considerable improvements of combustion process and would present the information for fundamental understanding in terms of reduced fuel consumption and exhaust emissions.

scholarly journals Analysis of the possibilities to achieve adiabatization process of combustion surrounded by inactive gases in Rapid Compression Machine

2017 ◽  
Vol 168 (1) ◽  
pp. 27-31
Author(s):  
Wojciech CIEŚLIK ◽  
Ireneusz PIELECHA
Keyword(s):  
Combustion Process ◽  
Combustible Mixture ◽  
Spark Ignition Engine ◽  
Rapid Compression Machine ◽  
Working Medium ◽  
Main Injection ◽  
Rapid Compression ◽  
Combustible Gases ◽  
Combustion Processes ◽  
Combustible Mixtures

In this work non-combustible gases impact on combustion processes studies is performed. Research was performed in a optically accessible rapid compression machine (RCM) under spark ignition engine conditions. The distribution of the swirl charge in the relation to adopted for analysis sequence of gas delivery to the chamber was varied with regard to the main injection. Authors investigate the influence of these sequence on the combustion and the ignition delay of the main injection and the overall combustion characteristics. The aim of this work is the experimental recognition of possibilities of creating combustible mixtures of light hydrocarbon fuels surrounded by non-combustible gases affecting the function of the inhibitor. Specifying the ability of preparation and combustion of mixtures in such systems enables the scientific analysis of adiabatization of the combustion process of fuel-air mixtures in the operating chambers. Theoretical analysis of the issues indicates possibility of obtaining such a stratification of the charge, that the inactive exhaust gases creating the outer ring surround the combustible mixture inside in such a way as to reduce the amount of heat exchanged between the working medium and the walls of the cylinder.

scholarly journals The technologies of improving the process of air-fuel mixture combustion in spark ignition engines

2020 ◽  
pp. 51-57
Author(s):  
A. P. Shaikin ◽  
◽  
I. R. Galiev ◽  
D. A. Pavlov ◽  
M. V. Sazonov ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Internal Combustion Engine ◽  
Flame Propagation ◽  
Turbulence Intensity ◽  
Propagation Velocity ◽  
Combustion Engine ◽  
Combustion Process ◽  
Fuel Mixture ◽  
Flame Propagation Velocity ◽  
Combustion Phase

The paper considers the turbulence intensity and the fuel chemical composition impact on the flame propagation velocity at the initial and main combustion phases when changing the air-fuel mixture composition. The relevance of the study is caused by the fact that currently, the improvement of conventional engine operation characteristics is mainly achieved through the improvement of the fuel mixture combustion process. However, there are no data on the influence of chemical and gas-dynamic factors on the peculiarities of flame propagation at the initial and main combustion phases. The gas reciprocating internal combustion engine was the object of the research, and the subject of the study was the fuel combustion process. Fuel chemical composition changed due to the promoting addition of hydrogen to the natural gas and variations of the excess-air coefficient. The experiments carried out on the UIT-85 power plant (i.e. under the simulated internal combustion engine conditions) show that the promoting addition of hydrogen stronger influences the flame velocity in the initial combustion phase compared to the second combustion phase, as a combustion source in the first phase is a laminar flame bent front and depends only on chemical and thermo-physical properties of the fuel-air mixture. The analysis of experimental data showed the dual impact of turbulence intensity on the flame propagation velocity. In particular, at the beginning of the combustion process, the fluctuating velocity scarcely influences the flame propagation velocity, as opposed to the main combustion phase, where the flame propagation velocity increases at the increase of turbulence intensity.

DeNOx mechanism caused by thermal cracking hydrocarbons in the stratified rich zone during diesel combustion

2005 ◽  
Vol 6 (6) ◽  
pp. 547-555 ◽  
Author(s):  
Y Kidoguchi ◽  
K Miwa ◽  
H Noge
Keyword(s):  
Flow Reactor ◽  
Reduction Process ◽  
Thermal Cracking ◽  
Chemical Kinetic ◽  
Diffusion Combustion ◽  
Diesel Combustion ◽  
Rapid Compression Machine ◽  
Combustion Phase ◽  
Rapid Compression ◽  
Cracking Process

This study concerns an experimental and theoretical investigation of the deNO x mechanism caused by thermal cracking hydrocarbons during diesel combustion. A total gas sampling experiment using a rapid compression machine showed that NO x can be reduced under fuel-rich and high-swirl conditions. It was found that under these conditions, a large amount of thermal cracking hydrocarbons, including unsaturated hydrocarbons such as C2H4, are produced during the ignition delay period, and that stratified fuel-rich combustion regions that contain these thermal cracking hydrocarbons are distributed widely throughout the combustion chamber. During the diffusion combustion phase, the CH4 concentration surpasses that of C2H4 and becomes the dominant hydrocarbon species. These thermal cracking hydrocarbons are supposed to be active in NO x reduction chemistry. To confirm the assumption, a flow reactor experiment was conducted focusing on the thermal cracking process of diesel fuel and the NO x reduction process. The experiment showed that when a solvent was used as fuel, light hydrocarbons similar to those observed in the rapid compression experiment are formed, and that about 60 per cent of NO x was reduced at equivalence ratios over 2.5 and a temperature of 1500 K. In addition to the above experiments, a chemical kinetic calculation using CHEMKIN III was carried out. The calculation revealed that C2H4 is easily decomposed during its oxidation process, forming HCCO or CHC2, which reacts promptly with NO and that in this reaction path, C2H22 formed through the thermal cracking process of C2H4 is an essential species to the formation of HCCO and CH2.

scholarly journals THE INFLUENCE OF HYDROGEN GAS ON THE MEASURES OF EFFICIENCY OF DIESEL INTERNAL COMBUSTION ENGINE / VANDENILIO DUJŲ ĮTAKA DYZELINIO VIDAUS DEGIMO VARIKLIO EFEKTYVUMO RODIKLIAMS

2014 ◽  
Vol 6 (5) ◽  
pp. 558-563
Author(s):  
Jurgis Latakas ◽  
Saugirdas Pukalskas ◽  
Alfredas Rimkus ◽  
Mindaugas Melaika ◽  
Ričardas Vėgneris ◽  
...  
Keyword(s):  
Combustion Engine ◽  
Process Analysis ◽  
Combustion Process ◽  
Research Literature ◽  
Hydrogen Gas ◽  
Engine Exhaust ◽  
Injection Angle ◽  
Diesel Injection ◽  
Combustion Phase ◽  
Carbon Dioxide Co2

In this research paper energy and ecological parameters of diesel engine which works under addition of hydrogen (10, 20, 30 l/ min) are presented. A survey of research literature has shown that addition of hydrogen gases improve diesel combustion; increase indicated pressure; decrease concentration of carbon dioxide (CO2), hydrocarbons (HC), particles; decrease fuel consumptions. Results of the experiment revealed that hydrogen gas additive decreased pressure in cylinder in kinetic combustion phase. Concentration of CO2 and nitrous oxides (NOx) decreased not significantly, HC – increased. Concentration of particles in engine exhaust gases significantly decreased. In case when hydrogen gas as additive was supplied, the fuel consumptions decreased a little. Using AVL BOOST software combustion process analysis was made. It was determined that in order to optimize engine work process under hydrogen additive usage, it is necessary to adjust diesel injection angle. Straipsnyje pateikiamas dyzelinio variklio, veikiančio su vandenilio priedu (10, 20, 30 l/min), energetinių ir ekologinių rodiklių tyrimas. Atlikus literatūros apžvalgą pastebėta, kad vandenilio dujų priedas pagerina dyzelino degimą, padidina indikatorinį slėgį, sumažina anglies dvideginio (CO2), angliavandenilių (HC), kietųjų dalelių koncentraciją, sumažina degalų sąnaudas. Bandymo rezultatai parodė, kad vandenilio dujų priedas sumažino variklio indikatorinį slėgį kinetinės degimo fazės metu. CO2 ir azoto oksidų (NOx) koncentracija nedaug sumažėjo, HC – padidėjo. Kietųjų dalelių koncentracija variklio išmetamosiose dujose itin sumažėjo. Tiekiant vandenilio dujas kaip priedą nedaug sumažėja dyzelino sąnaudos. AVL BOOST programa atlikta degimo proceso analizė. Nustatyta, kad siekiant optimizuoti variklio darbą, naudojant vandenilio priedą, būtina reguliuoti dyzelino įpurškimo paskubos kampą.

A Parametric Model for Ionization Current in a Four Stroke SI Engine

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Ingemar Andersson ◽  
Lars Eriksson
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Current Model ◽  
Combustion Process ◽  
Internal Combustion ◽  
Current Status ◽  
Cylinder Pressure ◽  
Ionization Current ◽  
Ionization Signal ◽  
Combustion Properties

A model for the thermal part of an ionization signal is presented that connects the ionization current to cylinder pressure and temperature in a spark ignited internal combustion engine. One strength of the model is that, after calibration, it has only two free parameters: burn angle and initial kernel temperature. By fitting the model to a measured ionization signal, it is possible to estimate both cylinder pressure and temperature, where the pressure is estimated with good accuracy. The model approach is validated on engine data. Cylinder pressure and ionization current data were collected on a Saab four-cylinder spark ignited engine for a variation in ignition timing and air-fuel ratio. The main result is that the parametrized ionization current model can be used to estimating combustion properties as pressure, temperature, and content of nitric oxides based on measured ionization currents. The current status of the model is suitable for off-line analysis of ionization currents and cylinder pressure. This ionization current model not only describes the connection between the ionization current and the combustion process, but also offers new possibilities for engine management system to control the internal combustion engine.

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