Download or read book Fuel Structure Effects on Surrogate Alternative Jet Fuel Emission written by Giacomo Flora and published by . This book was released on 2015 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: The emergence of alternative jet fuels has opened new challenges for the selection of practical alternatives that minimize the emissions and are suitable for existing gas turbine engines. Alternative jet fuels are in the early stages of development, and little fundamental emissions data are currently available. An accurate knowledge of their combustion behavior is highly important for a proper fuel selection based on emissions.This dissertation work investigated the oxidation of different alternative fuel surrogates composed of binary mixtures in order to correlate fuel composition with emissions. The proposed surrogate mixtures included n-dodecane/n-heptane (47.5/52.5 by liq. vol.), n-dodecane/iso-octane (47.9/52.1 by liq, vol.), n-dodecane/methylcyclohexane (49/51 by liq. vol.) and n-dodecane/m-xylene (75/25 by liq. vol.) mixtures. Experiments were carried out at the UDRI heated shock tube facility, and covered a pre-ignition temperature range of 950--1550 K at a pre-ignition pressure of ~16 atm, an equivalence ratio of 3, an argon concentration of 93% (by mol), and under homogeneous gas-phase conditions. Experimental data were modeled using the 2014 SERDP mechanism for jet fuel surrogates (525 species and 3199 reactions). Similar ignition delay times were measured for the tested surrogate blends, confirming previous observations regarding the controlling role of normal alkanes during the induction period. The experimental observation was also compared with modeling results reporting reasonably good agreements. A kinetic analysis of the SERDP 2014 mechanism was also performed, highlighting the major chemical pathways relevant to the pre-ignition chemistry, especially the role of the hydroperoxyl radical at the low temperatures. A wide speciation of combustion products was also carried out under the test conditions. All the aliphatic blends reported similar emissions, whereas the presence of m-xylene produced lower emissions than the aliphatic surrogate blends at lower temperatures. For certain species (light gases) this experimental observation was also supported by the kinetic mechanism predictions. However, aromatic species formed from combustion of n-dodecane/m-xylene surrogate blend were always overestimated by the model and in poor agreement with experimental observations. The results also confirmed the role of acetylene as assisting growth of large PAHs and formation of soot.

Download or read book Effects of Fuel Composition on Combustion Stability and NO Emissions for Traditional and Alternative Jet Fuels written by Shazib Z. Vijlee and published by . This book was released on 2014 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthetic jet fuels are studied to help understand their viability as alternatives to traditionally derived jet fuel. Two combustion parameters - flame stability and NOX emissions - are used to compare these fuels through experiments and models. At its core, this is a fuels study comparing how chemical makeup and behavior relate. Six 'real', complex fuels are studied in this work - four are synthetic from alternative sources and two are traditional from petroleum sources. Two of the synthetic fuels are derived from natural gas and coal via the Fischer Tropsch catalytic process. The other two are derived from Camelina oil and tallow via hydroprocessing. The traditional military jet fuel, JP8, is used as a baseline as it is derived from petroleum. The sixth fuel is derived from petroleum and is used to study the effects of aromatic content on the synthetic fuels. The synthetic fuels lack aromatic compounds, which are an important class of hydrocarbons necessary for fuel handling systems to function properly. Several single-component fuels are studied (through models and/or experiments) to facilitate interpretation and understanding. Methane is used for detailed modeling as it has a relatively small and well-understood chemical kinetic mechanism. Toluene, iso-octane, n-octane, propylcyclohexane, and 1,3,5-trimethylbenzene are included as they are all potential surrogates for jet fuel components. The flame stability study first compares all the `real', complex fuels for blowout. A toroidal stirred reactor is used to try and isolate temperature and chemical effects. The reactor has a volume of 250 mL and a residence time of approximately 8.0 ms. The air flow rate is held constant such that the inlet jets are sonic and turbulent mixing is present throughout the reactor. The fuel flow rate (hence equivalence ratio) is slowly lowered until the flame cannot sustain itself and it extinguishes. The results show that there is very little variation in blowout temperature and equivalence ratio for the synthetic fuels when compared to JP8 with low levels (0, 10, and 20%) of the aromatic additive. However, the 100% aromatic fuel behaved significantly differently and showed a lower resistance to blowout (i.e., it blew out at a higher temperature and equivalence ratio). The modeling study of blowout in the toroidal reactor is the key to understanding any fuel-based differences in blowout behavior. A detailed, reacting CFD model of methane is used to understand how the reactor stabilizes the flame and how that changes as the reactor approaches blowout. A 22 species reduced form of GRI 3.0 is used to model methane chemistry. The model shows that the reactor is quite homogenous at high temperatures, far away from blowout, and the transport of chain-initiating and chain-branching radical species is responsible for stabilizing the flame. Particularly, OH radical is recirculated around the reactor with enough concentration and at a high enough rate such that the radicals interact with the incoming fuel/air and initiate fuel decomposition. However, as equivalence ratio decreases, the reactor begins to behave in a more zonal nature and the radical concentration/location is no longer sufficient to initiate or sustain combustion. The knowledge of the radical species role is utilized to investigate the differences between a highly aliphatic fuel (surrogated by iso-octane) and a highly aromatic fuel (surrogated by toluene). A perfectly stirred reactor model is used to study the chemical kinetic pathways for these fuels near blowout. The differences in flame stabilization can be attributed to the rate at which these fuels are attacked and destroyed by radical species. The slow disintegration of the aromatic rings reduces the radical pool available for chain-initiating and chain-branching, which ultimately leads to an earlier blowout. The NOX study compares JP8, the aromatic additive, the synthetic fuels with and without an aromatic additive, and an aromatic surrogate (1,3,5-trimethylbenzene). A jet stirred reactor is used to try and isolate temperature and chemical effects. The reactor has a volume of 15.8 mL and a residence time of approximately 2.5 ms. The fuel flow rate (hence equivalence ratio) is adjusted to achieve nominally consistent temperatures of 1800, 1850, and 1900K. Small oscillations in fuel flow rate cause the data to appear in bands, which facilitated Arrhenius-type NOX-temperature correlations for direct comparison between fuels. The fuel comparisons are somewhat inconsistent, especially when the aromatic fuel is blended into the synthetic fuels. In general, the aromatic surrogate (1,3,5-trimethylbenzene) produces the most NOX, followed by JP8. The synthetic fuels (without aromatic additive) are always in the same ranking order for NOX production (HP Camelina > FT Coal > FT Natural Gas > HP Tallow). The aromatic additive ranks differently based on the temperature, which appears to indicate that some of the differences in NOX formation are due to the Zeldovich NOX formation pathway. The aromatic additive increases NOX for the HP Tallow and decreases NOX for the FT Coal. The aromatic additive causes increased NOX at low temperatures but decreases NOX at high temperatures for the HP Camelina and FT Natural Gas. A single perfectly stirred reactor model is used with several chemical kinetic mechanisms to study the effects of fuel (and fuel class) on NOX formation. The 27 unique NOX formation reactions from GRI 3.0 are added to published mechanisms for jet fuel surrogates. The investigation first looked at iso-octane and toluene and found that toluene produces more NOX because of a larger pool of O radical. The O radical concentration was lower for iso-octane because of an increased concentration of methyl (CH3) radical that consumes O radical readily. Several surrogate fuels (iso-octane, toluene, propylcyclohexane, n-octane, and 1,3,5-trimethylbenzene) are modeled to look for differences in NOX production. The trend (increased CH3→ decreased O → decreased NOX) is consistently true for all surrogate fuels with multiple kinetic mechanisms. It appears that the manner in which the fuel disintegrates and creates methyl radical is an extremely important aspect of how much NOX a fuel will produce.

Download or read book Characterization of Alternative Jet Fuels and Effect of Residual Oxygenated Functions Groups on Their Properties written by Anamaria Paiva Pinheiro Pires and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Green Aviation written by Emily S. Nelson and published by CRC Press. This book was released on 2018-06-12 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aircraft emissions currently account for ~3.5% of all greenhouse gas emissions. The number of passenger miles has increased by 5% annually despite 9/11, two wars and gloomy economic conditions. Since aircraft have no viable alternative to the internal combustion engine, improvements in aircraft efficiency and alternative fuel development become essential. This book comprehensively covers the relevant issues in green aviation. Environmental impacts, technology advances, public policy and economics are intricately linked to the pace of development that will be realized in the coming decades. Experts from NASA, industry and academia review current technology development in green aviation that will carry the industry through 2025 and beyond. This includes increased efficiency through better propulsion systems, reduced drag airframes, advanced materials and operational changes. Clean combustion and emission control of noise, exhaust gases and particulates are also addressed through combustor design and the use of alternative fuels. Economic imperatives from aircraft lifetime and maintenance logistics dictate the drive for "drop-in" fuels, blending jet-grade and biofuel. New certification standards for alternative fuels are outlined. Life Cycle Assessments are used to evaluate worldwide biofuel approaches, highlighting that there is no single rational approach for sustainable buildup. In fact, unless local conditions are considered, the use of biofuels can create a net increase in environmental impact as a result of biofuel manufacturing processes. Governmental experts evaluate current and future regulations and their impact on green aviation. Sustainable approaches to biofuel development are discussed for locations around the globe, including the US, EU, Brazil, China and India.

Download or read book Chemical Kinetic Modeling of Jet Fuel Surrogates written by Krithika Narayanaswamy and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Jet fuels, like typical transportation fuels, are mixtures of several hundreds of compounds belonging to different hydrocarbon classes. Their composition varies from one source to another, and only average fuel properties are known at best. In order to understand the combustion characteristics of the real fuels, and to address the problem of combustion control, computational studies using a detailed kinetic model to represent the real fuel, serves as a highly useful tool. However, the complexity of the real fuels makes it infeasible to simulate their combustion characteristics directly, requiring a simplified fuel representation to circumvent this difficulty. Typically, the real fuels are modeled using a representative surrogate mixture, i.e. a well-defined mixture comprised of a few components chosen to mimic the desired physical and chemical properties of the real fuel under consideration. Surrogates have been proposed for transportation fuels, including aviation fuels, and several kinetic modeling attempts for the proposed surrogates have also been made. However, (i) the fundamental kinetics of individual fuels, which make up the surrogate mixtures is not understood well, (ii) their combustion behavior at low through high temperatures has not been comprehensively validated, and this directly impacts the (iii) reliability of the multi-component reaction mechanism for a surrogate made up of these individual components. The present work is aimed at addressing the afore-mentioned concerns. The objective of this work is to develop a single, reliable kinetic model that can describe the oxidation of a few representative fuels, which are important components of transportation fuel surrogates, and thereby capture the specificities of the simpler, but still multi-component surrogates. The reaction mechanism is intended to well-represent the individual components as well as a multi-component surrogate for jet fuel made up of these fuel components. Further, this reaction mechanism is desired to be applicable at low through high temperatures, and be compact enough that chemical kinetic analysis is feasible. First, a representative compound for each of the major hydrocarbon classes found in the real jet fuel is identified. A surrogate for jet fuels is chosen to be comprised of n-dodecane (to represent normal alkanes), methylcyclohexane (to represent cyclic alkanes), and m-xylene (to represent aromatics). A Component Library approach is invoked for the development of a single, consistent, and reliable chemical scheme to accurately model this multi-component surrogate mixture. The chemical model is assembled in stages, starting with a base model and adding to it sub-mechanisms for the individual components of the surrogate, namely m- xylene, n-dodecane, and methylcyclohexane. The chemical model is validated comprehensively every time the oxidation pathways of a new component are incorporated into it and the experimental data is well captured by the simulations. In addition to the jet fuel surrogate, with the number of fuels described in the proposed reaction mechanism, a surrogate for the alternative Fischer-Tropsch fuels is also considered. Surrogates are defined for jet fuels and Fischer-Tropsch fuels by matching target properties important for combustion applications between the surrogate and the real fuel. The simulations performed using the proposed reaction mechanism, with the surrogates defined as fuels, are compared against global targets, such as ignition delays, flow reactor profiles, and flame speed measurements for representative jet fuels and Fischer-Tropsch fuels. The computations show promising agreement with these experimental data sets. The proposed reaction mechanism is well-suited to be used in real flow simulations of jet fuels. The proposed reaction mechanism has the ability to describe the kinetics of n- heptane, iso-octane, substituted aromatics, n-dodecane, and methylcyclohexane, all of which are important components of transportation fuel surrogates. Considering the large number of hydrocarbons whose kinetics are well described by this reaction mechanism, there are avenues for this reaction mechanism to be used to model other transportation fuels, such as gasoline, diesel, and alternative fuels, in addition to the jet and Fischer-Tropsch fuels discussed in the present study.

Download or read book Effects of Alternative Jet Fuels on Aerospace grade Composites Experimental and Modeling Studies written by Naoufal Harich and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aviation industry aims to reduce its environmental impact through innovation and research. The usage of composite materials for multiple primary structures represents one such measure. Several alternative fuels were approved and used along with the Federal Aviation Administration (FAA). These alternative fuels are produced from wastes and biomasses. Some alternative fuels were initially only approved as drop-in fuels, meaning they must be blended with conventional fuels to operate. Fuel tanks are usually embedded into the wing structure, which is mainly made of composite materials. These composites tend to absorb fluids it encounters through their matrix phase. The absorption behavior of conventional fuels by composite materials is well documented, while alternative fuels, blended or pure, are not as widely reported. The effects of four alternative fuel blends on aerospace-grade composites were investigated and compared with the conventional fuel Jet A. No significant differences were found in weight gain. The thermomechanical properties changes were also studied, with no difference between the alternative fuel blends and the conventional fuel. Additionally, model fluids with similar chemical structures as alternative fuels were used. The uptake of these model fluids was studied cyclically and compared with Jet A and one aromatic fluid. Small differences were seen in the weight gain results, primarily due to the type of model fluids used. Also, the thermomechanical properties showed no differences between these model fluids, Jet A and the pure aromatic fluid. This means that the slight differences in weight gain did not affect the changes in properties. From the results obtained, the alternative fuels blended, and the model fluids showed no differences in effects on the thermomechanical properties versus Jet A. This implies that similar effects are expected from either type of fluids used. Finite element analysis was used to model fluid's diffusion in composite materials using different material parameters. The parameters were fiber packing, arrangement and permeability. Each parameters impacted the equilibrium uptake and the diffusion rate differently.

Download or read book Effects of Fuel Molecular Structure on Emissions in a Jet Flame and a Model Gas Turbine Combustor written by Anandkumar Makwana and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Stricter environmental requirements, worldwide air traffic growth, and unsteady fuel prices all has led to an increased interest in alternative jet fuels. Additionally, several nations are investing resources identifying local fuel sources to make the fuel supply more resilient against disruptions and flexible to use of multiple, reliable fuel stocks. The alternative jet fuels that are being defined have unusual molecular distributions relative to current fuels. These differences in molecular structure affect the gas-phase kinetics during combustion, and hence the use of alternative fuels can impact emissions differently than conventional fuels. The differences in the emission characteristics between a newly developed alternative fuel and conventional fuel highlight the need to focus the research efforts on understanding how the fundamental properties of the fuel can affect emissions. The current work focuses on investigating the chemical effects of fuel molecular structure on the emission behavior of the fuels. In particular, the study explores how the fuel composition and premixing affect the production of polycyclic aromatic hydrocarbons (PAH), hazardous air pollutants (HAPs), and soot in a combustion environment. The study uses two experimental configurations: a jet flame and a model gas turbine combustor. Laser induced incandescence (LII) and laser extinction (LE) are used to obtain two-dimensional soot volume fraction in the flames. Laser induced fluorescence (LIF) is used to obtain the two-dimensional aromatic species distribution in the flames. Additionally, numerical analysis is used to investigate the effects of premixing on the soot formation processes in the jet flames for a high molecular weight fuel.

Download or read book Experimental and Numerical Studies for Soot Formation in Laminar Coflow Diffusion Flames of Jet A 1 and Synthetic Jet Fuels written by Meghdad Saffaripour and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surrogate Modeling of Alternative Jet Fuels for Study of Autoignition Characteristics written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alternative Jet Fuels and the Business of Freedom written by Monica Soria Baledon and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Reconciling the challenges of climate change and local pollution with those of economic growth and mobility, have become increasingly pressing and urgent. By 2050, carbon dioxide emissions from international and domestic aviation are anticipated to double their ~2.4% contribution to global warming; a figure that does not consider the radiative forcing effect of other emissions at cruise altitude.This doctoral dissertation investigated the role for alternative jet fuels (AJF) in mitigating the climate impacts of aviation in decades to come. This socio-environmental research was overarched by a Post-Normal Science (PNS) theoretical framework, where a mixed methodological approach to aeronautics and the application of out-of-field methods, were instrumental for the development of both the descriptive and the normative components of PNS. The descriptive component of PNS centered on the implications for environmental governance, of defining post-normal issues in terms of what is and what can be known. Its normative component focused on identifying mechanisms for informing and improving decision-making in the air transport sector, based on reflexive, inclusive and transparent scientific inquiry.The analysis of the discursive foundations of aviation climate policy, including the International Civil Aviation Organization's (ICAO) alternative jet fuel strategy, revealed abiding instances of data obliquity, information gaps and asymmetries underlying unquestioned forms of problem representations apropos the environmental impacts of air transport.Some of the options identified in this thesis for addressing these issues encompass: a) an enhanced transparency and access to data collected by governments, industry, academia and other third-parties on aviation emissions from and beyond fuel combustion, b) the harmonization of epistemologies for measuring, allocating, assessing, verifying and reporting environmental data so as to render it comparable, c) a reassessment of the sectoral approach to the Sustainable Development Goals (SDGs) for aligning aviation policies and actions with the aims of the UN 2030 Agenda for Sustainable Development, d) greater engagement of stakeholders in the qualitative production, appraisal and use of knowledge, and e) a broad outreach to end-users for getting them involved, individually, in climate action. Problem (mis)representations within the aviation sector have historically bolstered a weak sustainability approach to its sectoral growth that, unless unsettled and replaced by strong sustainability narratives, will continue to effect long-term micro and macroscale risks and repercussions on people and the environment. These discursive and non-discursive practices may also hinder future deployment of sustainable AJF - particularly in countries rich in fossil resources such as Canada - by encouraging the production of fossil-derived fuels, known as lower carbon aviation fuels (LCAF), and when more economical, by favoring carbon offsetting over direct emissions abatement.Weak sustainability narratives in the aviation sector can be challenged by participatory decision-making, where the understanding of what matters, why does it and who says so is as relevant to the future of AJF as their economies of scale. Multi-stakeholder partnerships are promising mechanisms for bringing ofttimes overlooked strong sustainability perspectives and expertise, into the formulation of policies and regulations on AJF beyond the work of the ICAO.To illustrate this, the Canadian case study offered a comprehensive overview of the status, obstacles, opportunities and next steps for strategically addressing commercialization barriers for AJF, by means of a national roadmap - SAFI Canada. This roadmap was the result of the active and pluralistic involvement of stakeholders within a community of interest on AJF that was partly gathered for this purpose"--

Download or read book Near term Feasibility of Alternative Jet Fuels written by and published by . This book was released on 2009 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: All economic sectors, including aviation, are experiencing growing pressure to reduce their greenhouse-gas (GHG) emissions. Aviation, however, has fewer alternative-energy options to petroleum-based fuels than other transportation sectors. Of alternatives that may be available (1) Fischer-Tropsch jet fuel produced from biomass or from a combination of coal and biomass with carbon capture and sequestration and (2) hydroprocessed renewable jet fuel may reduce aviation's impact on climate but are likely to be available only in limited quantities. Producing fuels yielding a net reduction in GHG emissions requires that biomass and renewable oil resources be produced so as not to incur land-use changes that would result in releases of carbon dioxide (CO2) and other GHGs. The economic benefits of producing alternative liquid fuels extend to all petroleum users. In particular, producing and using alternative liquid fuels yields benefits to commercial aviation, whether or not those fuels are used in aviation. Finally, moving to an ultra-low-sulfur specification for Jet A would reduce aviation's impact on air quality.

Download or read book Aviation Fuels written by Bhupendra Khandelwal and published by Elsevier. This book was released on 2021-07-26 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aviation Fuels provides up-to-date data on fuel effects on combustion performance and use of alternative fuels in aircraft. This book covers the latest advances on aviation fuel technologies, including alternative fuels, feedstocks and manufacturing processes, combustion performance, chemical modeling, fuel systems compatibility and the technical and environmental challenges for implementing the use of alternative fuels for aviation. Aviation fuel and combustion researchers, academics, and program managers for aviation technologies will value this comprehensive overview and summary on the present status of aviation fuels. Presents an overview on all relevant fields of aviation fuels, including production, approval, fuel systems compatibility and combustion (including emissions) Discusses the environmental impacts and carbon footprint of alternative fuels Features a chapter on electric flight and hydrogen powered aircraft and how its implementation will impact the aviation industry

Download or read book Scaling Air Quality Effects from Alternative Jet Fuel in Aircraft and Ground Support Equipment written by Pearl Elizabeth Donohoo-Vallett and published by . This book was released on 2010 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many of the nation's largest airports, including Los Angeles International Airport, the Hartsfield-Jackson Atlanta International Airport, Chicago O'Hare International Airport and Washington Dulles International Airport are located within areas designated by the EPA as having ambient particulate matter concentrations that exceed National Ambient Air Quality standards. When inhaled, fine particulate matter can enter the blood stream from the lungs and increase the risk of illness and premature mortality. This thesis examines the potential of two jet fuel types, ultra low sulfur jet fuel and synthetic paraffinic kerosene, to reduce aviation's contribution to ambient particulate matter concentrations. Scaling factors were developed for airport criteria pollutant emissions to model alternative jet fuels in aircraft and ground support equipment. These linear scaling factors were based on currently published studies comparing standard diesel and jet fuels with alternative jet fuels. It was found that alternative jet fuels lower or maintain all air pollutant emissions considered (primary particulate matter, sulfur oxides, nitrous oxides, unburned hydrocarbons and carbon monoxide) for both aircraft and ground support equipment. To quantify the potential benefits of changing fuel composition on ambient particulate matter concentrations, a study of the Atlanta Hartsfield Jackson International Airport was completed using both emissions inventory analysis and atmospheric modeling. The atmospheric modeling captures both primary particulate matter and other emissions that react in the atmosphere to form secondary particulate matter. It was found that the use of an ultra low sulfur jet fuel in aircraft gas turbines could reduce the primary particulate matter inventory by 37% and synthetic paraffinic kerosene could reduce the primary particulate matter inventory by 64%. The atmospheric modeling predicts that an ultra low sulfur jet fuel in aircraft could reduce ambient particulate matter concentrations due to aircraft by up to 57% and synthetic paraffinic kerosene could reduce particulate matter concentrations due to aircraft by up to 67%. Thus, this study indicates that the majority of air quality benefits at Atlanta Hartsfield Jackson International Airport that could be derived from the two fuels considered can be captured by removing the sulfur from jet fuel through the use of an ultra low sulfur jet fuel.

Download or read book The Implications of Alternative Aviation Fuels on Airbase Air Quality written by Harold A Scott (Jr) and published by . This book was released on 1980 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aircraft alternative fuel emission factors from turbine engine combustor performance tests are integrated into the Air Quality Assessment Model (AQAM) to predict the air quality impact of alternative fuels use in the vicinity of Air Force bases. AQAM computes the alternative fuel emission factors from fuel property inputs, enabling the model to predict concentrations for any proposed alternative fuel blend. In addition to aircraft alternative fuel emissions calculations, AQAM was modified to calculate alternative fuel handling and breathing loss emissions from the fuel properties. Using AQAM with two aircraft engine models, the aircraft alternative fuel annual emissions and resulting short-term pollutant concentrations are computed for a typical Air Force base. The analysis indicates that alternative fuel emissions cause a slight increase in pollution concentrations when compared with the baseline JP-4 fuel. A reduction of evaporative hydrocarbon emissions is predicted due to the alternative fuels' lower volatility in comparison with JP-4. (Author).

Download or read book Aviation Fuels written by Bhupendra Khandelwal and published by Academic Press. This book was released on 2021-07-20 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aviation Fuels provides up-to-date data on fuel effects on combustion performance and use of alternative fuels in aircraft. This book covers the latest advances on aviation fuel technologies, including alternative fuels, feedstocks and manufacturing processes, combustion performance, chemical modeling, fuel systems compatibility and the technical and environmental challenges for implementing the use of alternative fuels for aviation. Aviation fuel and combustion researchers, academics, and program managers for aviation technologies will value this comprehensive overview and summary on the present status of aviation fuels. Presents an overview on all relevant fields of aviation fuels, including production, approval, fuel systems compatibility and combustion (including emissions) Discusses the environmental impacts and carbon footprint of alternative fuels Features a chapter on electric flight and hydrogen powered aircraft and how its implementation will impact the aviation industry

Download or read book Modeling the Impact of Fuel Composition on Aircraft Engine NOx CO and Soot Emissions written by Lukas Frederik Jakob Brink and published by . This book was released on 2020 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aircraft NO[subscript x], CO and soot emissions contribute to climate change and lead to negative air quality impacts. With the aim of quantifying the effects of fuel composition on NO[subscript x], CO and soot emissions, a combustor model named Pycaso is developed. The combustor model consists of a 0D/1D reactor network, coupled with a soot model. The model predicts NO[subscript x], CO and soot emissions at sea level conditions for a CFM56-7B engine using conventional jet fuel. The model matches existing methods to predict cruise NO[subscript x] emissions within 5% and cruise CO emissions within 30%. It is shown that the volume -- and thus time -- over which secondary air is mixed with the fuel-air mixture in the combustor is the most important factor in determining the magnitudes of the modeled emissions. The sensitivity of modeled NO[subscript x] and CO emissions to thrust at thrust settings below 15% is shown to be the consequence of "cold" unburned fuel entering the secondary zone of the combustor. The model is used to assess two possible emission mitigation solutions: removing naphthalene from jet fuel and replacing conventional jet fuel with 50:50 biofuel blends. The removal of naphthalene through hydrotreating is found to lead to mean reductions in soot emissions of 15% [12%–20%] for mass and 9% [5%–19%] for number. The range captures variations in engine operating conditions, soot model configurations and compositions of the baseline jet fuel. Similarly, the removal of naphthalene through extractive distillation reduces soot mass emissions by 32% [29%–48%] and number emissions by 23% [14%–45%]. The mean reductions associated with using 50:50 biofuel blends are 43% [34%–59%] for soot mass and 35% [14%–45%] for soot number. Using biofuel blends is also predicted to result in a reduction in NO[subscript x] emissions of 5% [4%–7%] and a 3% [2%–4%] decrease in CO emissions.

Download or read book Development of Surrogates for Aviation Jet Fuels written by Seyed Ali Nasseri and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: