The main purpose of this work is to simulate turbulent premixed and expanding flame in an adiabat... more The main purpose of this work is to simulate turbulent premixed and expanding flame in an adiabatic combustion chamber without taking into account flame-walls interactions. The turbulence is supposed to be isotropic and homogeneous with no decay or decreasing, but spatially correlated. The chemistry is represented by a four-step scheme of methane-air combustion. A one-dimensional simulation is considered because of the spherically symmetric of the problem. Ignition occurs in the middle of the domain thanks to an energy source such a spark. The simulation, based on Monte Carlo scalar probability density functions (PDF) transport method, is used under different equivalence ratios (ER) and different turbulence intensities (u′). We have placed our emphasis on some flame characteristics such as the flame mean radius, the turbulent flame radius, the flame propagation velocity, and the flame brush thickness. The results of our simulations, carried out in similar conditions to some available experiments, are in good agreements. Indeed, we notice that the flame radius is enhanced by ER at constant u′, and by u′ at constant ER. The flame brush thickness shows a quick growth at the first stage and a moderate growth in the intermediate regime, but a bending effect is observed in the final stage of the so-called "fully developed flame".
Emission control science and technology, Sep 10, 2018
This research's basic objective is the study of hydrogen addition effects on pollutant emissions ... more This research's basic objective is the study of hydrogen addition effects on pollutant emissions like CO and CO 2 and on the laminar velocity of a methane flame considering a detailed chemical kinetics. This numerical study was performed using the calculation code of the gas phase chemical kinetics ChemKin4.0. To do this, the internal combustion engine (ICE) model was used to simulate the CO and CO 2 emissions and the flame speed calculation (FSC) model for calculating the laminar velocity for various detailed reaction mechanisms and under different mixing conditions of CH4 + H2 and at equivalence ratio values ranging from 0.6 to 1.4. Results were compared with various experimental data from the literature and very good concordance was observed for several of the detailed mechanisms.
Arabian journal for science and engineering, Jul 14, 2016
The focus of this research work is to investigate the effect of adding hydrogen on the laminar sp... more The focus of this research work is to investigate the effect of adding hydrogen on the laminar speed of hydrogen-enriched methane flame. The laminar velocities of methane–hydrogen–air mixtures are very important in designing and predicting the progress of combustion and performance of $$\hbox {H}_{2}$$H2-fueled combustion devices. In this study, laminar flame velocities of various compositions of $$\hbox {CH}_{4}{-}\hbox {H}_{2}$$CH4-H2–air mixtures (from 0 to 100 % hydrogen) have been calculated for different equivalence ratios (ranging from 0.6 to 1.4) and using several detailed reaction mechanisms. Simulations were carried out using the flame speed calculation (FSC) model of the chemical kinetics code Chemkin 4.02. The results of this study were compared with many measurements data of laminar flame speed from the literature, and good agreements were obtained for the whole range of hydrogen blends and equivalence ratios, especially with the detailed reaction mechanism GRIMech 3.0. This research demonstrates that the laminar burning velocity of methane flame was enhanced by the addition of hydrogen.
Three chem i cal ki netic mech a nisms of meth ane com bus tion were tested and compared us ing t... more Three chem i cal ki netic mech a nisms of meth ane com bus tion were tested and compared us ing the in ter nal com bus tion en gine model of Chemkin 4.02 [1]: one-step global re ac tion mech a nism, four-step mech a nism, and the stan dard de tailed scheme GRIMECH 3.0. This study shows good con cor dances, es pe cially be tween the four-step and the detailed mech a nisms in the pre dic tion of tem per a ture and main spe cies pro files. But re duced schemes were in ca pables to pre dict pol lut ant emis sions in an in ter nal combus tion en gine. The four-step mech a nism can only pre dict CO emis sions but without good agree ment.
The main purpose of this work is to test the validation of use of a four step reaction mechanism ... more The main purpose of this work is to test the validation of use of a four step reaction mechanism to simulate the laminar speed of hydrogen enriched methane flame. The laminar velocities of hydrogenmethane-air mixtures are very important in designing and predicting the progress of combustion and performance of combustion systems where hydrogen is used as fuel. In this work, laminar flame velocities of different composition of hydrogen-methane-air mixtures (from 0% to 40% hydrogen) have been calculated for variable equivalence ratios (from 0.5 to 1.5) using the flame propagation module (FSC) of the chemical kinetics software Chemkin 4.02. Our results were tested against an extended database of laminar flame speed measurements from the literature and good agreements were obtained especially for fuel lean and stoichiometric mixtures for the whole range of hydrogen blends. However, in the case of fuel rich mixtures, a slight overprediction (about 10%) is observed. Note that this overprediction decreases significantly with increasing hydrogen content. This research demonstrates that reduced chemical kinetics mechanisms can well reproduce the laminar burning velocity of methane-hydrogen-air mixtures at lean and stoichiometric mixture flame for hydrogen content in the fuel up to 40%. The use of such reduced mechanisms in complex combustion device can reduce the available computational resources and cost because the number of species is reduced.
International Journal of Automotive Science and Technology, 2021
This work represents an experimental study on the performances of a single cylinder spark-ignitio... more This work represents an experimental study on the performances of a single cylinder spark-ignition marine engine fueled by ethanol blends. Several studies have been carried out to investigate the use of alternative fuels in spark-ignition engines to improve their efficiency and reduce exhaust emissions. The experiments have been conducted on a test bed under full load condition with varied engine speed from 1000 rpm to 3000 rpm and an engine wall’s temperature fixed between 75°C – 85°C. The study includes the blending of ethanol and gasoline with different blending ratios (E0, E5, E15, and E20). The results of the study showed that E15 conducted for better results in specific fuel consumption without notable loss in engine performances in comparison with other blends. Experiments showed that ethanol blends are a viable option as a fuel alternative in spark-ignition engines due to its potential to conserve acceptable engine performances.
Alternative fuels have the potential to reduce exhaust emissions in the transportation sector. In... more Alternative fuels have the potential to reduce exhaust emissions in the transportation sector. In this study, the effects of oxygenated fuels on the performance and emissions of a gasoline single-cylinder spark-ignition engine have been investigated experimentally. Experiments were conducted using a DIDACTA-T85 testbed under full load conditions and variable engine speed. Performance tests were performed by measuring the brake torque, brake power, brake mean effective pressure (BMEP), brake specific fuel consumption (BSFC), and brake thermal efficiency (BTE). The tested fuel blends were G0, E10, A10, and M10. G0 represented the base fuel and pure gasoline. E10, A10, and M10 were represented by a 10% volume of ethanol, acetone, and methanol in gasoline respectively. Results showed that M10 produced better engine performance in terms of brake torque, brake power, and BMEP, while E10 performed better results in terms of BSFC and BTE. A10 gave the lowest value in NOx emission at all eng...
The main objective of this paper is to develop a general predictive mathematical model of direct ... more The main objective of this paper is to develop a general predictive mathematical model of direct contact membrane distillation (DCMD) for flat sheet module. This model, based on fundamental equations of mass and heat transfer, aims to predict the water permeate flux across the membrane and to investigate the influence of membrane characteristics such as its thickness, its length, the pore size and porosity, on the performance of DCMD process. All physical parameters implemented in the mathematical model have been estimated using appropriate temperature correlations. Obtained results revealed that doubling the thickness of the membrane decreases the permeate flux by an amount of 43% and increasing the membrane porosity by 20% yields an increase of the permeate flux by 40%. However, pore size as well as membrane length variations show no sensitive effect on permeate flux. A good agreement between this theoretical model and experimental data was observed for various feed temperatures. This suggests that this tool could be utilized efficiently to predict permeate flux values for DCMD process.
Three chemical kinetic mechanisms of methane combustion were tested and compared using the intern... more Three chemical kinetic mechanisms of methane combustion were tested and compared using the internal combustion engine model of Chemkin 4.02 [1]: one-step global reaction mechanism, four-step mechanism, and the standard detailed scheme GRIMECH 3.0. This study shows good concordances, especially between the four-step and the detailed mechanisms in the prediction of temperature and main species profiles. But reduced schemes were incapables to predict pollutant emissions in an internal combustion engine. The four-step mechanism can only predict CO emissions but without good agreement.
Three reduced chemical kinetic mechanisms of methane combustion were tested and compared with the... more Three reduced chemical kinetic mechanisms of methane combustion were tested and compared with the standard detailed scheme GriMech 3.0., using the internal combustion engine (ICE) model of Chemkin 4.02 [1]. This study shows acceptable concordances in the prediction of temperature and main species profiles. But reduced schemes were incapables to predict all polluant emissions in an internal combustion engine.
International Journal of Online Engineering (iJOE), 2015
This paper focuses on the implementation of the first remote laboratory in the mechanical field b... more This paper focuses on the implementation of the first remote laboratory in the mechanical field being used by the Higher Institute of Industrial Systems of Gabès (ISSIG)-Gabès University, Tunisia. The developed remote laboratory is achieved thanks to the e-Sience Tempus project. The control system for this remote laboratory was implemented using LabVIEW software. The experiment studies the forced vibrations system. The students access our platform via the internet to determine the resonance frequency of damping forced vibration from the amplitude vs. excitation frequency and the phase angle vs. excitation curves. The students also determined the damping ration for system via phase angle vs. excitation frequency curve. All online experiments were deployed on the interactive version of iLab Shared Architecture (ISA).
Three chem i cal ki netic mech a nisms of meth ane com bus tion were tested and compared us ing t... more Three chem i cal ki netic mech a nisms of meth ane com bus tion were tested and compared us ing the in ter nal com bus tion en gine model of Chemkin 4.02 [1]: one-step global re ac tion mech a nism, four-step mech a nism, and the stan dard de tailed scheme GRIMECH 3.0. This study shows good con cor dances, es pe cially be tween the four-step and the detailed mech a nisms in the pre dic tion of tem per a ture and main spe cies pro files. But re duced schemes were in ca pables to pre dict pol lut ant emis sions in an in ter nal combus tion en gine. The four-step mech a nism can only pre dict CO emis sions but without good agree ment.
The main purpose of this work is to simulate turbulent premixed and expanding flame in an adiabat... more The main purpose of this work is to simulate turbulent premixed and expanding flame in an adiabatic combustion chamber without taking into account flame-walls interactions. The turbulence is supposed to be isotropic and homogeneous with no decay or decreasing, but spatially correlated. The chemistry is represented by a four-step scheme of methane-air combustion. A one-dimensional simulation is considered because of the spherically symmetric of the problem. Ignition occurs in the middle of the domain thanks to an energy source such a spark. The simulation, based on Monte Carlo scalar probability density functions (PDF) transport method, is used under different equivalence ratios (ER) and different turbulence intensities (u′). We have placed our emphasis on some flame characteristics such as the flame mean radius, the turbulent flame radius, the flame propagation velocity, and the flame brush thickness. The results of our simulations, carried out in similar conditions to some available experiments, are in good agreements. Indeed, we notice that the flame radius is enhanced by ER at constant u′, and by u′ at constant ER. The flame brush thickness shows a quick growth at the first stage and a moderate growth in the intermediate regime, but a bending effect is observed in the final stage of the so-called "fully developed flame".
Emission control science and technology, Sep 10, 2018
This research's basic objective is the study of hydrogen addition effects on pollutant emissions ... more This research's basic objective is the study of hydrogen addition effects on pollutant emissions like CO and CO 2 and on the laminar velocity of a methane flame considering a detailed chemical kinetics. This numerical study was performed using the calculation code of the gas phase chemical kinetics ChemKin4.0. To do this, the internal combustion engine (ICE) model was used to simulate the CO and CO 2 emissions and the flame speed calculation (FSC) model for calculating the laminar velocity for various detailed reaction mechanisms and under different mixing conditions of CH4 + H2 and at equivalence ratio values ranging from 0.6 to 1.4. Results were compared with various experimental data from the literature and very good concordance was observed for several of the detailed mechanisms.
Arabian journal for science and engineering, Jul 14, 2016
The focus of this research work is to investigate the effect of adding hydrogen on the laminar sp... more The focus of this research work is to investigate the effect of adding hydrogen on the laminar speed of hydrogen-enriched methane flame. The laminar velocities of methane–hydrogen–air mixtures are very important in designing and predicting the progress of combustion and performance of $$\hbox {H}_{2}$$H2-fueled combustion devices. In this study, laminar flame velocities of various compositions of $$\hbox {CH}_{4}{-}\hbox {H}_{2}$$CH4-H2–air mixtures (from 0 to 100 % hydrogen) have been calculated for different equivalence ratios (ranging from 0.6 to 1.4) and using several detailed reaction mechanisms. Simulations were carried out using the flame speed calculation (FSC) model of the chemical kinetics code Chemkin 4.02. The results of this study were compared with many measurements data of laminar flame speed from the literature, and good agreements were obtained for the whole range of hydrogen blends and equivalence ratios, especially with the detailed reaction mechanism GRIMech 3.0. This research demonstrates that the laminar burning velocity of methane flame was enhanced by the addition of hydrogen.
Three chem i cal ki netic mech a nisms of meth ane com bus tion were tested and compared us ing t... more Three chem i cal ki netic mech a nisms of meth ane com bus tion were tested and compared us ing the in ter nal com bus tion en gine model of Chemkin 4.02 [1]: one-step global re ac tion mech a nism, four-step mech a nism, and the stan dard de tailed scheme GRIMECH 3.0. This study shows good con cor dances, es pe cially be tween the four-step and the detailed mech a nisms in the pre dic tion of tem per a ture and main spe cies pro files. But re duced schemes were in ca pables to pre dict pol lut ant emis sions in an in ter nal combus tion en gine. The four-step mech a nism can only pre dict CO emis sions but without good agree ment.
The main purpose of this work is to test the validation of use of a four step reaction mechanism ... more The main purpose of this work is to test the validation of use of a four step reaction mechanism to simulate the laminar speed of hydrogen enriched methane flame. The laminar velocities of hydrogenmethane-air mixtures are very important in designing and predicting the progress of combustion and performance of combustion systems where hydrogen is used as fuel. In this work, laminar flame velocities of different composition of hydrogen-methane-air mixtures (from 0% to 40% hydrogen) have been calculated for variable equivalence ratios (from 0.5 to 1.5) using the flame propagation module (FSC) of the chemical kinetics software Chemkin 4.02. Our results were tested against an extended database of laminar flame speed measurements from the literature and good agreements were obtained especially for fuel lean and stoichiometric mixtures for the whole range of hydrogen blends. However, in the case of fuel rich mixtures, a slight overprediction (about 10%) is observed. Note that this overprediction decreases significantly with increasing hydrogen content. This research demonstrates that reduced chemical kinetics mechanisms can well reproduce the laminar burning velocity of methane-hydrogen-air mixtures at lean and stoichiometric mixture flame for hydrogen content in the fuel up to 40%. The use of such reduced mechanisms in complex combustion device can reduce the available computational resources and cost because the number of species is reduced.
International Journal of Automotive Science and Technology, 2021
This work represents an experimental study on the performances of a single cylinder spark-ignitio... more This work represents an experimental study on the performances of a single cylinder spark-ignition marine engine fueled by ethanol blends. Several studies have been carried out to investigate the use of alternative fuels in spark-ignition engines to improve their efficiency and reduce exhaust emissions. The experiments have been conducted on a test bed under full load condition with varied engine speed from 1000 rpm to 3000 rpm and an engine wall’s temperature fixed between 75°C – 85°C. The study includes the blending of ethanol and gasoline with different blending ratios (E0, E5, E15, and E20). The results of the study showed that E15 conducted for better results in specific fuel consumption without notable loss in engine performances in comparison with other blends. Experiments showed that ethanol blends are a viable option as a fuel alternative in spark-ignition engines due to its potential to conserve acceptable engine performances.
Alternative fuels have the potential to reduce exhaust emissions in the transportation sector. In... more Alternative fuels have the potential to reduce exhaust emissions in the transportation sector. In this study, the effects of oxygenated fuels on the performance and emissions of a gasoline single-cylinder spark-ignition engine have been investigated experimentally. Experiments were conducted using a DIDACTA-T85 testbed under full load conditions and variable engine speed. Performance tests were performed by measuring the brake torque, brake power, brake mean effective pressure (BMEP), brake specific fuel consumption (BSFC), and brake thermal efficiency (BTE). The tested fuel blends were G0, E10, A10, and M10. G0 represented the base fuel and pure gasoline. E10, A10, and M10 were represented by a 10% volume of ethanol, acetone, and methanol in gasoline respectively. Results showed that M10 produced better engine performance in terms of brake torque, brake power, and BMEP, while E10 performed better results in terms of BSFC and BTE. A10 gave the lowest value in NOx emission at all eng...
The main objective of this paper is to develop a general predictive mathematical model of direct ... more The main objective of this paper is to develop a general predictive mathematical model of direct contact membrane distillation (DCMD) for flat sheet module. This model, based on fundamental equations of mass and heat transfer, aims to predict the water permeate flux across the membrane and to investigate the influence of membrane characteristics such as its thickness, its length, the pore size and porosity, on the performance of DCMD process. All physical parameters implemented in the mathematical model have been estimated using appropriate temperature correlations. Obtained results revealed that doubling the thickness of the membrane decreases the permeate flux by an amount of 43% and increasing the membrane porosity by 20% yields an increase of the permeate flux by 40%. However, pore size as well as membrane length variations show no sensitive effect on permeate flux. A good agreement between this theoretical model and experimental data was observed for various feed temperatures. This suggests that this tool could be utilized efficiently to predict permeate flux values for DCMD process.
Three chemical kinetic mechanisms of methane combustion were tested and compared using the intern... more Three chemical kinetic mechanisms of methane combustion were tested and compared using the internal combustion engine model of Chemkin 4.02 [1]: one-step global reaction mechanism, four-step mechanism, and the standard detailed scheme GRIMECH 3.0. This study shows good concordances, especially between the four-step and the detailed mechanisms in the prediction of temperature and main species profiles. But reduced schemes were incapables to predict pollutant emissions in an internal combustion engine. The four-step mechanism can only predict CO emissions but without good agreement.
Three reduced chemical kinetic mechanisms of methane combustion were tested and compared with the... more Three reduced chemical kinetic mechanisms of methane combustion were tested and compared with the standard detailed scheme GriMech 3.0., using the internal combustion engine (ICE) model of Chemkin 4.02 [1]. This study shows acceptable concordances in the prediction of temperature and main species profiles. But reduced schemes were incapables to predict all polluant emissions in an internal combustion engine.
International Journal of Online Engineering (iJOE), 2015
This paper focuses on the implementation of the first remote laboratory in the mechanical field b... more This paper focuses on the implementation of the first remote laboratory in the mechanical field being used by the Higher Institute of Industrial Systems of Gabès (ISSIG)-Gabès University, Tunisia. The developed remote laboratory is achieved thanks to the e-Sience Tempus project. The control system for this remote laboratory was implemented using LabVIEW software. The experiment studies the forced vibrations system. The students access our platform via the internet to determine the resonance frequency of damping forced vibration from the amplitude vs. excitation frequency and the phase angle vs. excitation curves. The students also determined the damping ration for system via phase angle vs. excitation frequency curve. All online experiments were deployed on the interactive version of iLab Shared Architecture (ISA).
Three chem i cal ki netic mech a nisms of meth ane com bus tion were tested and compared us ing t... more Three chem i cal ki netic mech a nisms of meth ane com bus tion were tested and compared us ing the in ter nal com bus tion en gine model of Chemkin 4.02 [1]: one-step global re ac tion mech a nism, four-step mech a nism, and the stan dard de tailed scheme GRIMECH 3.0. This study shows good con cor dances, es pe cially be tween the four-step and the detailed mech a nisms in the pre dic tion of tem per a ture and main spe cies pro files. But re duced schemes were in ca pables to pre dict pol lut ant emis sions in an in ter nal combus tion en gine. The four-step mech a nism can only pre dict CO emis sions but without good agree ment.
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