Mazen Eldeeb - Academia.edu (original) (raw)

Papers by Mazen Eldeeb

In this work, a chemical kinetic modeling study of the high-temperature ignition and laminar flam... more In this work, a chemical kinetic modeling study of the high-temperature ignition and laminar flame behavior of Tetrahydrofuran (THF), a promising second-generation transportation biofuel, is presented. Stochastic Species Elimination (SSE) model reduction approach (Eldeeb and Akih-Kumgeh, Proceedings of ASME Power Conference 2018) is implemented to develop multiple skeletal versions of a detailed chemical kinetic model of THF (Fenard et al., Combustion and Flame, 2018) based on ignition delay time simulations at various pressures and temperature ranges. The detailed THF model contains 467 species and 2390 reactions. The developed skeletal versions are combined into an overall reduced model of THF, consisting of 193 species and 1151 reactions. Ignition delay time simulations are performed using detailed and reduced models, with varying levels of agreement observed at most conditions. Sensitivity analysis is then performed to identify the most important reactions responsible for the ob...

The advancement of combustion technology through computer-aided development of novel combustion e... more The advancement of combustion technology through computer-aided development of novel combustion engines leads to cleaner and more efficient transportation systems. In these developments, numerical modeling, valued for its flexibility and low cost compared to experiments, is a powerful tool used for the prediction of combustion and emissions behavior of potential transportation fuels. However, two main challenges limit combustion simulations. Research requires different types of numerical models to simulate separate combustion problems, such as auto-ignition and flame propagation. Also, larger detailed models provide accurate predictions at the expense of time and computational resources. Addressing such challenges would lead to less time-consuming simultaneous simulation of different combustion problems without sacrificing accuracy.

Bulletin of the American Physical Society, 2013

Volume 4B: Combustion, Fuels, and Emissions, 2019

For the purposes of combustion analysis, n-dodecane is used as the surrogate or a surrogate compo... more For the purposes of combustion analysis, n-dodecane is used as the surrogate or a surrogate component for biodiesel and jet fuel. In order to capture kinetic effects in computational combustion, detailed and reduced models of n-dodecane are therefore used. This paper presents a comparative analysis of selected detailed chemical kinetic models of n-dodecane as well as reduction of these detailed models to more compact skeletal versions. The selected models are compared based on their ability to predict ignition phenomena. Measured ignition delay times from the literature are used as references. Both low- and high-temperature ignition simulations are considered. To further facilitate future computational combustion analysis, the detailed models are reduced using the Alternative Species Elimination (ASE) approach reported by Akih-Kumgeh and Bergthorson (Energy & Fuels, 2316–2326, 2013). The resulting skeletal models are compared in terms of their retained species, ranked species sensit...

The high-temperature auto-ignition delay times of dimethyl and ethyl isomers of c yclohexane and ... more The high-temperature auto-ignition delay times of dimethyl and ethyl isomers of c yclohexane and furan are carried out behind reflected shock waves at average press ures of 5.0 and 12.0 atm. The study is aimed at establishing reactivity differences between these dimethyl and eth yl isomers which could further be explored in chemical kinetic modeling. The two hydrocarbon clas ses are designed to test whether the observed trend is indicative of general reactivity differen ces between dimethyl and ethyl isomers of cyclic hydrocarbons, oxygenated or non-oxygenated. It is observed that 2,5-dimethyl furan ignition delay times are up to 5 times longer than those of the more reactive ethyl fu ran. The dimethyl cyclohexane investigated is a mixture of 1,3-cis-dimethyl and 1,3-trans-dimeth yl cyclohexane. In the case of the cyclohexanes, a similar trend is observed such that 1,3-dimethy l cyclohexane has longer ignition delay times than the ethyl isomer, albeit to a lesser extent than observe...

International Journal of Chemical Kinetics, 2016

The ignition behavior of methyl furan (2-MF) and methyl tetrahydrofuran (2-MTHF) is investigated ... more The ignition behavior of methyl furan (2-MF) and methyl tetrahydrofuran (2-MTHF) is investigated using the shock tube technique. Experiments are carried out using homogeneous gaseous mixtures of fuel, oxygen, and argon with equivalence ratios, ϕ, of 0.5, 1.0, and 2.0 at average pressures of 3 and 12 atm over a temperature range of 1060–1300 K. In addition to ignition delay time measurements, fuel concentration time histories during ignition and pyrolysis of 2-MTHF are obtained by means of laser absorption spectroscopy using a He–Ne laser at a fixed wavelength of 3.39 µm. With respect to ignition delay times, it is observed that under similar conditions of equivalence ratio and argon/oxygen ratio (D), 2-MTHF has longer ignition delay times than 2-MF at 3 atm. In addition, 2-MTHF has longer ignition delay times than 2-MF at higher temperatures for the case of 12 atm and under the same conditions of ϕ and D. The higher reactivity of 2-MF, as indicated by shorter ignition delay times, is attributed to differences in chemical structure, whereby weaker C–H bond sites are more readily susceptible to radical attack than in 2-MTHF. It is observed that ignition delay times of 2-MTHF decrease with increasing equivalence ratio at 12 atm for fixed argon/oxygen ratio. Ignition delay times are compared with model predictions using recent chemical kinetic models of both fuels, showing that both models generally predict shorter ignition delay times than measured. The relatively higher absorption cross section of 2-MTHF at 3.39 µm allows for its concentration time histories to be determined and compared to model predictions. In line with the observed discrepancy in ignition predictions, predicted 2-MTHF concentration profiles are such that the fuel is shown to be more rapidly consumed than observed in the experiments. The study advances understanding of the combustion chemistry of these cyclic ethers that are potential alternative fuels.

for helping me in my experimental work and for making the lab an enjoyable place. I would like to... more for helping me in my experimental work and for making the lab an enjoyable place. I would like to acknowledge the support of my colleagues Amirali Montakhab, Deshawn Coombs, Jenna Philipp, and David Zheng. I would like to thank the undergraduate summer researchers, Robert Dreiker, Cory Prykull, Marcos Fernandes, and Ranon Bezerra for their hard work and dedication during the design and setup stages of the shock tube facility. I would like to express my gratitude to my family. My mother, Sahar Shabka, whose prayers and never-ending love have been a lifetime blessing. My father, Prof. Ali Eldeeb, for constantly encouraging me to reach my full potential. My little brother, Omar, for being the best brother and friend one could have. And my little sister, Balsam, for her kindness and prayers. Last but not least, I wouldn't have been able to achieve this work without the love of my life; my wife Noha. The PhD experience can be very stressful and even nerve-breaking. However, she miraculously kept me sane during my worst times here. Her love, kindness, and sense of humor have always been my only fail-safe against breakdown. She has always believed in me unconditionally, and for this, her endless sacrifices are most appreciated. Finally, I would like to welcome my first son, Eyad, who arrived to this World on November 3, 2015. He is my eternal source of support and strength, as his name indicates. This work, as well as my whole life, are dedicated to my wife and son. And above all, glory and praise be to Allah the Almighty. I am grateful for His love, care and inspiration. I borrow words from the angels' praise to Allah when He asked them to tell Him the names of things. They replied: "Glory be to You. You alone are free from defect. We possess only that much knowledge which You have given us. Indeed You alone are All-Knowing and All-Wise." The Holy Quran,

Energies

There is growing interest in the use of furans, a class of alternative fuels derived from biomass... more There is growing interest in the use of furans, a class of alternative fuels derived from biomass, as transportation fuels. This paper reviews recent progress in the characterization of its combustion properties. It reviews their production processes, theoretical kinetic explorations and fundamental combustion properties. The theoretical efforts are focused on the mechanistic pathways for furan decomposition and oxidation, as well as the development of detailed chemical kinetic models. The experiments reviewed are mostly concerned with the temporal evolutions of homogeneous reactors and the propagation of laminar flames. The main thrust in homogeneous reactors is to determine global chemical time scales such as ignition delay times. Some studies have adopted a comparative approach to bring out reactivity differences. Chemical kinetic models with varying degrees of predictive success have been established. Experiments have revealed the relative behavior of their combustion. The growing body of literature in this area of combustion chemistry of alternative fuels shows a great potential for these fuels in terms of sustainable production and engine performance. However, these studies raise further questions regarding the chemical interactions of furans with other hydrocarbons. There are also open questions about the toxicity of the byproducts of combustion.

Combustion and Flame, 2015

Energy & Fuels, 2014

ABSTRACT A systematic study of the ignition behavior of furan and the substituted furans 2-methyl... more ABSTRACT A systematic study of the ignition behavior of furan and the substituted furans 2-methyl furan (2-MF) and 2,5-dimethyl furan (DMF) is presented. Ignition delay times are measured over a temperature range from 977 to 1570 K and pressures up to 12 atm for lean, stoichiometric, and rich mixtures of fuel, oxygen, and argon. It is found that when the equivalence ratio ϕ, the argon-to-oxygen ratio D, and pressure p are kept constant over a range of temperatures T, DMF generally has the longest, while 2-MF has the shortest, ignition delay times, and furan shows intermediate reactivity. Ignition delay times decrease with increasing equivalence ratios, except for DMF, which does not show a conclusive trend over the temperature range investigated. The experimental data are also found to agree with published ignition data, showing differences in some cases partly related to disparities in endwall and sidewall ignition measurements. The ignition delay times of 2-MF and DMF are compared to predictions using furan chemical kinetic models by Sirjean et al. and Somers et al. The models show qualitatively that DMF has longer ignition delay times than 2-MF under similar conditions of ϕ, D, p, and T, as revealed by the experiments. Quantitatively, the model predictions agree with experimental data at conditions similar to those used in their development, and deviations from experiment at other conditions are mostly related to unmatched temperature sensitivities over a wider temperature range, revealed by varying pressure and reduced dilution. The reported experimental data set contributes toward further understanding and improved modeling of the combustion of furans, a promising class of alternative fuels.

49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2011

ABSTRACT The thermoacoustic engine is a device that converts heat energy into sound or acoustic p... more ABSTRACT The thermoacoustic engine is a device that converts heat energy into sound or acoustic power. They are used currently to recover waste heat from military vehicles and converting it to electricity, which means that such devices can play a significant role in power generation for domestic & commercial purposes. This study demonstrates an attempt to design a 1-meter-long thermoacoustic heat engine with optimum efficiency. This will be done using DeltaEC, a software which was developed especially for the modeling of low amplitude thermoacoustic devices. The optimization process includes geometrical parameters of the resonator tube and the stack, the working fluid, and the heat input to the engine. The present optimization process has shown that slab stacks made of Celcor (a Ceramic material) demonstrated much better performance than other stack shapes and materials. For a 1.1239-meter-long and 0.011 m2 square-shaped resonator tube, a 7.75 cm long slab stack made of Celcor having 0.304 mm-thick-plates, spaced by 0.648 mm, giving a porosity ratio of 0.68067, will theoretically convert heat to acoustic power at an efficiency of 30.611% which is equivalent to 47.97% of Carnot’s efficiency.

9th Annual International Energy Conversion Engineering Conference, 2011

ABSTRACT doi:10.2514/6.2011-5803