scholarly journals An Influence of Correction of the Ignition Advance Angle on the Combustion Process in SI Engine Fuelled by LPG with the Addition of DME

2019 ◽  
Vol 26 (4) ◽  
pp. 285-292
Author(s):  
Grzegorz Kubica ◽  
Paweł Marzec
Keyword(s):  
Full Range ◽  
Combustion Process ◽  
Experimental Tests ◽  
Point Of View ◽  
Si Engine ◽  
Fuel Component ◽  
Gaseous Fuels ◽  
Basic Engine ◽  
Positive Effect ◽  
Fuel Components

AbstractThe paper presents the results of tests of the SI engine fuelled by LPG with the addition of DME in the form of a mixture of gaseous fuels. Experimental tests were carried out on a chassis dynamometer in the full range of engine loads, at a fixed rotational speed: 2000, 2500 and 3000 rpm. The use of dimethyl ether (DME) as a fuel component makes it possible to exploit its important advantages. DME can be produced as a renewable fuel, which is important from the point of view of ecology. Another important fact is the presence of oxygen in this fuel, which has a positive effect on the engine volumetric efficiency. During the tests, the ignition timing was also adjusted due to the very good DME flammability. Two additional correction levels were applied, increasing the ignition advance by 3 and 6 CA degrees, compared to the factory settings of the driver. The analysis of the obtained results allowed determining the dependence of the basic engine parameters, in the function of the correction of ignition advance angle. In the summary, attention was also paid to the possibility of determining corrected maps of the ignition advance angle taking into account the variable proportions of fuel components.

A Comprehensive Kinetics Library for Simulating the Combustion of Automotive Fuels

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Chitralkumar V. Naik ◽  
Karthik V. Puduppakkam ◽  
Ellen Meeks
Keyword(s):  
Carbon Number ◽  
Chemical Properties ◽  
Estimation Methods ◽  
Specific Rate ◽  
Fuel Component ◽  
Number Range ◽  
Gaseous Fuels ◽  
Design Concepts ◽  
Reduction Methods ◽  
Fuel Components

We have developed a surrogate blending methodology to identify surrogates with a desired degree of complexity. Along with estimation methods for various physical and chemical properties for fuel blends, we have assembled and developed a rich library of over 60 fuel components. The components cover a carbon number range from 1 to 20, and chemical classes including linear and branched alkanes, olefins, aromatics with one and two rings, alcohols, esters, and ethers. With these, surrogates can be formulated to represent most gasoline, diesel, gaseous fuels, renewable fuels, and several additives. As part of the library, we have assembled self-consistent and detailed reaction mechanisms for all the components, as well as for emissions including NOx and polycyclic aromatic hydrocarbons and a detailed soot-surface mechanism. An extensive validation suite has been used to improve the kinetics database such that good predictions and agreement to data are achieved for the fuel components and fuel-component blends, within experimental uncertainties. This effectively eliminates the need to tune specific rate parameters when employing the kinetics mechanisms in combustion simulations. For engine simulations, the master mechanisms have been reduced using a combination of available reduction methods while strictly controlling the error tolerances for targeted predictions. This approach has resulted in small mechanisms for efficiently incorporating the validated kinetics into computational fluid dynamics (CFD) applications. The surrogate formulation methodology, the comprehensive fuel library, and mechanism reduction strategies suggested in this work allow the use of CFD to explore design concepts and fuel effects in engines with reliable predictions.

scholarly journals Researches on Soot Filtration Process by Comparing Simulation and Experimental Tests

2021 ◽  
Vol 44 (4) ◽  
pp. 54-59
Author(s):  
Bogdan Manolin JURCHIȘ
Keyword(s):  
Particle Filter ◽  
Combustion Engine ◽  
Combustion Process ◽  
Engine Performance ◽  
Experimental Tests ◽  
Point Of View ◽  
Pollutant Emissions ◽  
Particulate Filter ◽  
The Creation ◽  
Two Stages

In this paper, the main objective of using numerical simulation was to highlight and analyse details that are very difficult to highlight through experimental tests. The development of the simulation model was also done for predictive purposes. In other words, after validation of the model, it can be used to estimate the filter load in other conditions than the experimental ones, respectively to evaluate how the particulate filter affects the operation of the internal combustion engine. In order to achieve the desired result, the creation of the model was done in two stages, the first stage was the creation of a model containing all the components of the engine, except the particle filter in order to identify the parameters of the combustion process and pollutant emissions - model validated on the basis of the indicated pressure curves, and the second stage was to complete the initial model with a particle filter and validate it from the point of view of the pressure drop, respectively of the engine performance, the aim was to obtain a trend, respectively values similar to the experimental ones.

Combustion Development Investigation in a Common Rail Multi-Jet Diesel Engine With Up to 4 Injections per Engine Cycle

2005 ◽  
Author(s):  
Fabrizio Ponti ◽  
Gabriele Serra ◽  
Carlo Siviero
Keyword(s):  
Degrees Of Freedom ◽  
Combustion Process ◽  
Experimental Tests ◽  
Point Of View ◽  
Injection System ◽  
Combustion Model ◽  
Jet Engines ◽  
Injection Parameters ◽  
Start Of Injection ◽  
Engine Cycle

Newly developed technologies for modern diesel engines allow designing injection patterns with many degrees of freedom. Multi-jet engines, for example, can perform up to 5 injections within the same engine cycle: Position and duration of each injection, together with rail pressure and EGR rate can be chosen in order to properly design the desired in-cylinder combustion process. This means that during the injection system setup process all the free parameters have to be set to the desired value. If all the injection parameters variations have to be investigated in order to properly set their values, a huge amount of experimental tests should be needed. From this point of view, in order to reduce the need for test bench experimental work, the development of a combustion model can be very useful, to help determining the best injection configuration, and therefore the desired combustion into the cylinder. Single zone combustion models seem to be suitable for this task, thanks to the quick response they can give, and the possibility of using them for control purposes. In the paper a model developed for injection patterns with up to 4 injections is used in order to describe the combustion behavior as a function of the injection parameters. A properly designed set of tests has been performed in order to identify the combustion model. The obtained results give information on the way the combustion parameters, for example the combustion delays (i.e. the time delays between each Start Of Injection SOI, and the corresponding Start Of Combustion SOC), or the amount of fuel burnt for each injection are modified as the combustion process proceeds into the cylinder or as the injection parameters change. The information obtained can be in the following used in order to design the desired injection pattern, using the identified model as a virtual experimental tests generator.

Development and Application of Industrial Gas Turbines for Medium-Btu Gaseous Fuels

1986 ◽  
Vol 108 (1) ◽  
pp. 182-190 ◽  
Author(s):  
J. G. Meier ◽  
W. S. Y. Hung ◽  
V. M. Sood
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Process ◽  
Point Of View ◽  
Combustion System ◽  
Successful Development ◽  
Gaseous Fuels ◽  
Sanitary Landfills ◽  
Industrial Gas Turbines ◽  
Alternate Fuels

This paper describes the successful development and application of industrial gas turbines using medium-Btu gaseous fuels, including those derived from biodegradation of organic matters found in sanitary landfills and liquid sewage. The effects on the gas turbine and its combustion system of burning these alternate fuels compared to burning high-Btu fuels, along with the gas turbine development required to use alternate fuels from the point of view of combustion process, control system, gas turbine durability, maintainability and safety, are discussed.

Combined Experimental and Numerical Analysis of the Influence of Air-to-Fuel Ratio on Cyclic Variation of High Performance Engines

2008 ◽  
Author(s):  
Claudio Forte ◽  
Gian Marco Bianchi ◽  
Enrico Corti ◽  
Stefano Fantoni
Keyword(s):  
High Performance ◽  
Combustion Process ◽  
Experimental Tests ◽  
Cylinder Pressure ◽  
Pressure Data ◽  
Si Engine ◽  
Complex Phenomena ◽  
Experimental Pressure ◽  
Mixture Homogeneity ◽  
Insight Into

The Cycle by Cycle Variation (CCV) of a SI engine is analyzed by combining experimental tests and numerical investigations. The quantification of CCV is based on the evaluation of the Coefficient of Variance (COV) of IMEP. The analysis of the experimental pressure data shows an increase in CCV towards leaner mixture conditions. The evaluation of the Heat Release Rate from the in-cylinder pressure traces reveals the strong influence of the early stages of combustion on the variability of the flame evolution. In order to evaluate the influence on CCV of local air equivalence ratio cycle-to-cycle variability and mixture homogeneity in the chamber, a numerical CFD methodology for the simulation of the combustion process has been proposed. The results reproduce with reasonable accuracy the increase in CCV with leaner combustions and put the basis for a deeper insight into the complex phenomena involved in the combustion process by the use of parametric analysis.

scholarly journals THE INFLUENCE OF SELECTED GASEOUS FUELS ON THE COMBUSTION PROCESS IN THE SI ENGINE

2017 ◽  
Vol 12 (3) ◽  
pp. 135-146 ◽  
Author(s):  
Marek FLEKIEWICZ ◽  
Grzegorz KUBICA
Keyword(s):  
Combustion Process ◽  
Si Engine ◽  
Gaseous Fuels

scholarly journals Determinants of Corporate Anti-Corruption Disclosure: The Case of the Emerging Economics

2021 ◽  
Vol 13 (6) ◽  
pp. 3462
Author(s):  
Maider Aldaz Odriozola ◽  
Igor Álvarez Etxeberria
Keyword(s):  
Empirical Studies ◽  
Geographical Area ◽  
Control Variable ◽  
Emerging Countries ◽  
Point Of View ◽  
Press Freedom ◽  
Negative Effects ◽  
Key Factor ◽  
Using Data ◽  
Positive Effect

Corruption is a key factor that affects countries’ development, with emerging countries being a geographical area in which it tends to generate greater negative effects. However, few empirical studies analyze corruption from the point of view of disclosure by companies in this relevant geographical area. Based on a regression analysis using data from the 96 large companies from 15 emerging countries included in the 2016 International Transparency Report, this paper seeks to understand what determinants affect such disclosure. In that context, this paper provides empirical evidence to understand the factors that influence reporting on anti-corruption mechanisms in an area of high economic importance that has been little studied to date, pointing to the positive effect of press freedom in a country where the company is located and with the industry being the unique control variable that strengthens this relationship.

scholarly journals Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3521 ◽  
Author(s):  
Panagiotis Stathopoulos
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Process ◽  
Ideal Gas ◽  
Point Of View ◽  
Pressure Gain Combustion ◽  
Combustion Technology ◽  
Secondary Air ◽  
And Performance ◽  
The Impact

Conventional gas turbines are approaching their efficiency limits and performance gains are becoming increasingly difficult to achieve. Pressure Gain Combustion (PGC) has emerged as a very promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine thermodynamic cycles. Up to date, only very simplified models of open cycle gas turbines with pressure gain combustion have been considered. However, the integration of a fundamentally different combustion technology will be inherently connected with additional losses. Entropy generation in the combustion process, combustor inlet pressure loss (a central issue for pressure gain combustors), and the impact of PGC on the secondary air system (especially blade cooling) are all very important parameters that have been neglected. The current work uses the Humphrey cycle in an attempt to address all these issues in order to provide gas turbine component designers with benchmark efficiency values for individual components of gas turbines with PGC. The analysis concludes with some recommendations for the best strategy to integrate turbine expanders with PGC combustors. This is done from a purely thermodynamic point of view, again with the goal to deliver design benchmark values for a more realistic interpretation of the cycle.

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.

Sign in / Sign up

Export Citation Format

Share Document