scholarly journals Theoretical approach to modeling the combustion process in turbine engines fuelled by alternative aviation fuels containing various components/biocomponents

2017 ◽  
Vol 171 (4) ◽  
pp. 245-249
Author(s):  
Andrzej KULCZYCKI
Keyword(s):  
Mathematical Model ◽  
Chemical Composition ◽  
Mathematical Models ◽  
Combustion Chamber ◽  
Theoretical Approach ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Turbine Engines ◽  
Alternative Aviation Fuels ◽  
Combustion Processes

The aim of this paper is presentation of the possibility of combustion processes modelling so that to better describe the influence of fuels chemistry on fuels combustion. This is important for prediction the behaviour of different alternative fuels in processes in combustion chamber. Currently used mathematical models do not sufficiently take into account the influence of fuels chemical composition on combustion process. The idea of new mathematical model is proposed in this paper. The paper presents the main assumptions of this model and the results of its preliminary verification using MiniJetRig.

scholarly journals Reactivity Model as a Tool to Compare the Combustion Process in Aviation Turbine Engines Powered by Synthetic Fuels

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6302
Author(s):  
Tomasz Białecki ◽  
Wojciech Dzięgielewski ◽  
Mirosław Kowalski ◽  
Andrzej Kulczycki
Keyword(s):  
Alternative Fuels ◽  
Combustion Process ◽  
Carbon Oxide ◽  
Jet Fuel ◽  
Turbine Engines ◽  
Power Functions ◽  
Synthetic Fuels ◽  
Proposed Model ◽  
Oxide Concentration ◽  
Combustion Processes

The paper aims to verify the thesis that the reactivity model, developed in earlier research, can be used to compare the fuels combustion processes in turbine engines, which is important for predicting the behavior of different alternative fuels in combustion process. Synthetic blending components from alcohol to jet and hydroprocessed esters and fatty acids technologies and their blends with conventional jet fuel were used in tests. The undertaken laboratory tests reveal the differences between the properties of the tested fuels. Bench tests were carried out on a test rig with a miniature turbojet engine, according to authorial methodology. For each blend, on selected points of rotational speed the carbon oxide concentration in the exhaust gases was recorded. The obtained results allowed the formulation of empirical power functions describing relations between carbon oxide concentration and fuel mass flow rate. Based on general assumptions, the reactivity model was adopted to compare the combustion processes of the different fuels in turbine engines. The directions of further research on the development of the proposed model were indicated.

Phenomenological Modeling of Combustion in Pre-Chamber and the Pilot Flame for Natural Gas Engines

2019 ◽  
Author(s):  
Long Liu ◽  
Xia Wen ◽  
Qian Xiong ◽  
Xiuzhen Ma
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Alternative Fuels ◽  
Gas Flow ◽  
Combustion Process ◽  
Clean Energy ◽  
Combustion Model ◽  
Flame Surface ◽  
Flow Process ◽  
Natural Gas Engines

Abstract With energy shortages and increasing environmental problems, natural gas, as a clean energy, has the advantages of cheap price and large reserves and has become one of the main alternative fuels for marine diesel engines. For large bore natural gas engines, pre-chamber spark plug ignition can be used to increase engine efficiency. The engine mainly relies on the flame ejected from the pre-chamber to ignite the mixture of natural gas and air in the main combustion chamber. The ignition flame in the main combustion chamber is the main factor affecting the combustion process. Although the pre-chamber natural gas engines have been extensively studied, the characteristics of combustion in the pre-chamber and the development of ignition flame in the main combustion chamber have not been fully understood. In this study, a two-zone phenomenological combustion model of pre-chamber spark-ignition natural gas engines is established based on the exchange of mass and energy of the gas flow process in the pre-chamber and the main combustion chamber. The basic characteristics of the developed model are: a spherical flame surface is used to describe the combustion state in the pre-chamber, and according to the turbulent jet theory, the influence of turbulence on the state of the pilot flame is considered based on the Reynolds number. According to the phenomenological model, the time when the flame starts to be injected from the pre-chamber to the main combustion chamber, and the parameters such as the length of the pilot flame are analyzed. The model was verified by experimental data, and the results showed that the calculated values were in good agreement with the experimental values. It provides an effective tool for mastering the law of flame development and supporting the optimization of combustion efficiency.

A Control-Oriented Jet Ignition Combustion Model for an SI Engine

2015 ◽  
Author(s):  
Ruitao Song ◽  
Gerald Gentz ◽  
Guoming Zhu ◽  
Elisa Toulson ◽  
Harold Schock
Keyword(s):  
Combustion Chamber ◽  
Combustion Process ◽  
Turbulent Jets ◽  
Combustion Stability ◽  
Combustion Model ◽  
Combustion Chambers ◽  
Si Engine ◽  
Lean Operations ◽  
Combustion Processes ◽  
Hil Simulation

A turbulent jet ignition system of a spark ignited (SI) engine consists of pre-combustion and main-combustion chambers, where the combustion in the main-combustion chamber is initiated by turbulent jets of reacting products from the pre-combustion chamber. If the gas exchange and combustion processes are accurately controlled, the highly distributed ignition will enable very fast combustion and improve combustion stability under lean operations, which leads to high thermal efficiency, knock limit extension, and near zero NOx emissions. For model-based control, a precise combustion model is a necessity. This paper presents a control-oriented jet ignition combustion model, which is developed based on simplified fluid dynamics and thermodynamics, and implemented into a dSPACE based real-time hardware-in-the-loop (HIL) simulation environment. The two-zone combustion model is developed to simulate the combustion process in two combustion chambers. Correspondingly, the gas flowing through the orifices between two combustion chambers is divided into burned and unburned gases during the combustion process. The pressure traces measured from a rapid compression machine (RCM), equipped with a jet igniter, are used for initial model validation. The HIL simulation results show a good agreement with the experimental data.

Characterization of Emissions From the Use of Alternative Aviation Fuels

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Tak W. Chan ◽  
Wajid A. Chishty ◽  
Pervez Canteenwalla ◽  
David Buote ◽  
Craig R. Davison
Keyword(s):  
Particulate Matter ◽  
Chemical Composition ◽  
Environmental Sustainability ◽  
Alternative Fuels ◽  
Gaseous Emissions ◽  
Fischer Tropsch ◽  
Alternative Aviation Fuels ◽  
Significant Difference ◽  
Particulate Matter Emissions

Alternative fuels for aviation are now a reality. These fuels not only reduce reliance on conventional petroleum-based fuels as the primary propulsion source, but also offer promise for environmental sustainability. While these alternative fuels meet the aviation fuels standards and their overall properties resemble those of the conventional fuel, they are expected to demonstrate different exhaust emissions characteristics because of the inherent variations in their chemical composition resulting from the variations involved in the processing of these fuels. This paper presents the results of back-to-back comparison of emissions characterization tests that were performed using three alternative aviation fuels in a GE CF-700-2D-2 engine core. The fuels used were an unblended synthetic kerosene fuel with aromatics (SKA), an unblended Fischer–Tropsch (FT) synthetic paraffinic kerosene (SPK) and a semisynthetic 50–50 blend of Jet A-1 and hydroprocessed SPK. Results indicate that while there is little dissimilarity in the gaseous emissions profiles from these alternative fuels, there is however a significant difference in the particulate matter emissions from these fuels. These differences are primarily attributed to the variations in the aromatic and hydrogen contents in the fuels with some contributions from the hydrogen-to-carbon ratio of the fuels.

scholarly journals Introduction to the problem of calculating the parameters of the mixing chamber of an afterburning bypass engine

2021 ◽  
Vol 20 (3) ◽  
pp. 57-64
Author(s):  
O. D. Karev
Keyword(s):  
Mathematical Modeling ◽  
Chemical Composition ◽  
Mathematical Models ◽  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Turbine Engine ◽  
The Core ◽  
Mixing Chamber ◽  
Mixing Chambers

The article considers the problem of calculation accuracy when using mathematical models of gas-turbine engines of the second level of complexity, using the example of a device for mixing the flows of the core engine and the bypass duct of a gas turbine engine, and suggests methods for solving it. The processes taking place in mixing chambers of air-breather engines are considered to be difficult for mathematical modeling since the exchange of kinetic and thermal energies of the flows characterized by different velocities, pressures, temperatures and chemical composition occurs in them simultaneously. The mixer does not only ensure mixing of flows from different engine ducts, but also acts as a kind of throttle. It regulates the pressure downstream of the fan and, consequently, air consumption in the bypass duct, thus affecting directly the fan characteristics and the distribution of flows over the engine ducts. The paper presents the dependencies of the workflow parameters that allow for more accurate verification of mixer models of the second level of complexity.

Characterization of Emissions From the Use of Alternative Aviation Fuels

2015 ◽  
Author(s):  
Tak W. Chan ◽  
Wajid A. Chishty ◽  
Pervez Canteenwalla ◽  
David Buote ◽  
Craig R. Davison
Keyword(s):  
Particulate Matter ◽  
Chemical Composition ◽  
Environmental Sustainability ◽  
Alternative Fuels ◽  
Gaseous Emissions ◽  
Fischer Tropsch ◽  
Alternative Aviation Fuels ◽  
Significant Difference ◽  
Particulate Matter Emissions

Alternative fuels for aviation are now a reality. These fuels not only reduce reliance on conventional petroleum-based fuels as the primary propulsion source, but also offer promise for environmental sustainability. While these alternative fuels meet the aviation fuels standards and their overall properties resemble those of the conventional fuel, they are expected to demonstrate different exhaust emissions characteristics because of the inherent variations in their chemical composition resulting from the variations involved in the processing of these fuels. This paper presents the results of back-to-back comparison of emissions characterization tests that were performed using three alternative aviation fuels in a GE CF-700-2D-2 engine core. The fuels used were an unblended synthetic kerosene fuel with aromatics (SKA), an unblended Fischer Tropsch synthetic paraffinic kerosene (SPK) and a semi-synthetic 50-50 blend of Jet A-1 and hydroprocessed SPK. Results indicate that while there is little dissimilarity in the gaseous emissions profiles from these alternative fuels, there is however a significant difference in the particulate matter emissions from these fuels. These differences are primarily attributed to the variations in the aromatic and hydrogen contents in the fuels with some contributions from the hydrogen-to-carbon ratio of the fuels.

scholarly journals EFFECT OF CNG IN A FUEL DOSE ON THE COMBUSTION PROCESS OF A COMPRESSION-IGNITION ENGINE

Transport ◽  
2015 ◽  
Vol 30 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Maciej Mikulski ◽  
Sławomir Wierzbicki
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Diesel Oil ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Compression Ignition Engines ◽  
Main Component

Currently, one of the major trends in the research of contemporary combustion engines involves the potential use of alternative fuels. Considerable attention has been devoted to methane, which is the main component of Natural Gas (NG) and can also be obtained by purification of biogas. In compression-ignition engines fired with methane or Compressed Natural Gas (CNG), it is necessary to apply a dual-fuel feeding system. This paper presents the effect of the proportion of CNG in a fuel dose on the process of combustion. The recorded time series of pressure in a combustion chamber was used to determine the repeatability of the combustion process and the change of fuel compression-ignition delay in the combustion chamber. It has been showed that NG does not burn completely in a dual-fuel engine. The best conditions for combustion are ensured with higher concentrations of gaseous fuel. NG ignition does not take place simultaneously with diesel oil ignition. Moreover, if a divided dose of diesel is injected, NG ignition probably takes place at two points, as diesel oil.

scholarly journals Effect of Hard Coal Combustion in Water Steam Environment on Chemical Composition of Exhaust Gases

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6530
Author(s):  
Bartosz Ciupek ◽  
Karol Gołoś ◽  
Radosław Jankowski ◽  
Zbigniew Nadolny
Keyword(s):  
Chemical Composition ◽  
Combustion Chamber ◽  
Coal Combustion ◽  
Mass Concentration ◽  
Combustion Process ◽  
Hard Coal ◽  
Nitric Oxides ◽  
Water Steam ◽  
Exhaust Gases ◽  
Academic Paper

This academic paper revolves around the results of research on the change in emission parameters of the used heating boiler following the introduction of the overheated water stream, which had an impact on different emission parameters. The research results provide an insight into the hard coal combustion process, which had a significant impact on the change in the chemical composition of exhaust gases: it contributed to the lower mass concentration of the emitted dust and black carbon (PM) as well as nitric oxides (NOx) while, at the same time, playing a significant role in increasing the mass concentration of the emitted carbon oxide (CO). Two types of devices were used for the purposes of conducting the research at hand: a boiler with an automatic fuel feeding system with one combustion chamber and a boiler with a combustion chamber and an afterburning chamber fitted over it. Apart from the measurements of mass concentration of the emitted harmful substances, the research also focused on measurements of temperature inside the combustion and afterburning chambers, as well as the temperature of exhaust gases and their oxygen content. As part of the research, water steam was introduced to the combustion and afterburning chambers at the flow rate of 0.71 kg/h and 3.60 kg/h for boilers operating at a minimum power of 30% and a nominal power of 100%. An original steam generator with an overheated water steam production range from 0.71 kg/h to 3.60 kg/h was used to create and feed the water steam. The efficiency of the combustion process was calculated using the obtained results for each operating configuration of a given boiler.

scholarly journals Design and development of combustion chambers for gas turbine engines based on calculations of various levels of complexity

2021 ◽  
Vol 20 (3) ◽  
pp. 7-23
Author(s):  
Y. B. Aleksandrov ◽  
T. D. Nguyen ◽  
B. G. Mingazov
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Flow ◽  
Combustion Process ◽  
Three Dimensional ◽  
Numerical Calculations ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Combustion Chambers ◽  
Flame Tube

The article proposes a method for designing combustion chambers for gas turbine engines based on a combination of the use of calculations in a one-dimensional and three-dimensional formulation of the problem. This technique allows you to quickly design at the initial stage of creating and development of the existing combustion chambers using simplified calculation algorithms. At the final stage, detailed calculations are carried out using three-dimensional numerical calculations. The method includes hydraulic calculations, on the basis of which the distribution of the air flow passing through the main elements of the combustion chamber is determined. Then, the mixing of the gas flow downstream of the flame tube head and the air passing through the holes in the flame tube is determined. The mixing quality determines the distribution of local mixture compositions along the length of the flame tube. The calculation of the combustion process is carried out with the determination of the combustion efficiency, temperature, concentrations of harmful substances and other parameters. The proposed method is tested drawing on the example of a combustion chamber of the cannular type. The results of numerical calculations, experimental data and values obtained using the proposed method for various operating modes of the engine are compared.

Potential of alcohol fuels in active and passive pre-chamber applications in a passenger car spark-ignition engine

2021 ◽  
pp. 146808742110531
Author(s):  
Patrick Burkardt ◽  
Christian Wouters ◽  
Stefan Pischinger
Keyword(s):  
Combustion Chamber ◽  
Alternative Fuels ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Passenger Car ◽  
Excess Air ◽  
Lean Limit ◽  
Alcohol Fuels

Both the shift from fossil to alternative fuels and the implementation of a pre-chamber combustion system allow for an increase in the efficiency of an internal combustion engine through optimizing its combustion process, while simultaneously reducing the engine-out emissions. The combination of alcohol-based fuels and pre-chamber combustion concepts has not been investigated on spark-ignition engines with high compression ratios in a passenger car size. This study presents investigations to show the potential in maximum achievable lean limit and net indicated efficiency. In particular, we present investigations of two alternative alcohol fuels on a direct-injection spark-ignition single-cylinder research engine for passenger car applications with a compression ratio of 16.4. The engine was operated with both an active and a passive pre-chamber, and the experimental results were compared to those of conventional spark-ignition operation. Direct injection was used for both the main combustion chamber and the pre-chamber. Methanol and ethanol were used as fuels for the main combustion chamber, whereas exclusively ethanol was used for the pre-chamber fueling. The performance of the alcohol fuels in all combustion configurations was evaluated in both part-load and high-load conditions. In particular, investigations of the combustion behavior over a variation of the excess air ratio at indicated mean effective pressures of 6 and 15 bar were performed. It can be concluded that with the use of methanol as fuel for the main combustion chamber, both higher excess air ratios and higher indicated efficiencies were achieved compared to the use of ethanol as the main combustion chamber fuel. In particular, a maximum net indicated efficiency of 48% at an excess air ratio of 2.0 was achieved with methanol. Moreover, active pre-chamber operation extended the lean limit to an excess air ratio of 2.3 compared to the maximum lean limit of 1.7 in passive pre-chamber operation.

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