Articoli di riviste sul tema "Aeronautic emissions"
Segui questo link per vedere altri tipi di pubblicazioni sul tema: Aeronautic emissions.
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 articoli di riviste per l'attività di ricerca sul tema "Aeronautic emissions".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi gli articoli di riviste di molte aree scientifiche e compila una bibliografia corretta.
1
Talero, Gabriel, Camilo Bayona-Roa, Giovanny Muñoz, Miguel Galindo, Vladimir Silva, Juan Pava e Mauricio Lopez. "Experimental Methodology and Facility for the J69-Engine Performance and Emissions Evaluation Using Jet A1 and Biodiesel Blends". Energies 12, n. 23 (28 novembre 2019): 4530. http://dx.doi.org/10.3390/en12234530.
Abstract (sommario):
Aeronautic transport is a leading energy consumer that strongly contributes to greenhouse gas emissions due to a significant dependency on fossil fuels. Biodiesel, a substitution of conventional fuels, is considered as an alternative fuel for aircrafts and power generation turbine engines. Unfortunately, experimentation has been mostly limited to small scale turbines, and technical challenges remain open regarding operational safety. The current study presents the facility, the instrumentation, and the measured results of experimental tests in a 640 kW full-scale J69-T-25A turbojet engine, operating with blends of Jet A1 and oil palm biodiesel with volume contents from 0% to 10% at different load regimes. Findings are related to the fuel injection system, the engine thrust, and the emissions. The thrust force and the exhaust gas temperature do not expose a significant variation in all the operation regimes with the utilization of up to 10% volume content of biodiesel. A maximum increase of 36% in fuel consumption and 11% in injection pressure are observed at idle operation between B0 and B10. A reduction of the CO and HC emissions is also registered with a maximum variation at the cruise regime (80% Revolutions Per Minute—RPM).
2
Riba, Jordi-Roger, Álvaro Gómez-Pau, Manuel Moreno-Eguilaz e Santiago Bogarra. "Arc Tracking Control in Insulation Systems for Aeronautic Applications: Challenges, Opportunities, and Research Needs". Sensors 20, n. 6 (16 marzo 2020): 1654. http://dx.doi.org/10.3390/s20061654.
Abstract (sommario):
Next generation aircrafts will use more electrical power to reduce weight, fuel consumption, system complexity and greenhouse gas emissions. However, new failure modes and challenges arise related to the required voltage increase and consequent rise of electrical stress on wiring insulation materials, thus increasing the risk of electrical arc appearance. This work performs a critical and comprehensive review concerning arc tracking effects in wiring insulation systems, underlying mechanisms, role of materials and possible mitigation strategies, with a special focus on aircraft applications. To this end an evaluation of the scientific and technological state of the art is carried out from the analysis of theses, research articles, technical reports, international standards and white papers. This review paper also reports the limitations of existing insulation materials, standard test methods and mitigation approaches, while identifying the research needs to comply with the future demands of the aircraft industry.
3
Frosina, Emma, Adolfo Senatore, Luka Palumbo, Giuseppe Di Lorenzo e Ciro Pascarella. "Development of a Lumped Parameter Model for an Aeronautic Hybrid Electric Propulsion System". Aerospace 5, n. 4 (4 ottobre 2018): 105. http://dx.doi.org/10.3390/aerospace5040105.
Abstract (sommario):
This paper describes a case study for applying a hybrid electric propulsion system for general aviation aircraft. The work was performed by a joint team from the Centro Italiano Ricerche Aerospaziali (CIRA) and the Department of Industrial Engineering of the University of Naples Federico II. The use of electric and hybrid electric propulsion for aircraft has gained widespread and significant attention over the past decade. The driver of industry interest has principally been the need to reduce the emissions of combustion engine exhaust products and noise; however, studies have revealed the potential for overall improvement in the energy efficiency and mission flexibility of new aircraft types. The goal of the present study was to demonstrate the feasibility of aeronautic parallel hybrid electric propulsion for light aircraft, varying mission profiles and electric configurations. Through the creation and application of a global model with AMESim® software, in which every aspect of the components chosen by the industrial partners can be represented, some interesting studies were carried out. The numerical model used was more complete and more accurate compared to some others available in the literature. In particular, it was confirmed that, for particular missions, integrating state-of-the-art technologies provides notable advantages for aircraft hybrid electric propulsion for light aircraft.
4
Palma, Giorgio, e Lorenzo Burghignoli. "On the integration of acoustic phase-gradient metasurfaces in aeronautics". International Journal of Aeroacoustics 19, n. 6-8 (10 settembre 2020): 294–309. http://dx.doi.org/10.1177/1475472x20954404.
Abstract (sommario):
Metamaterials might be one of the breakthrough technologies needed from the aeronautic industry to achieve the more and more challenging targets set by the international authorities, especially about noise emissions. In this article, a theoretical link between Transformation Acoustics and Generalized Snell’s Law, two widely used metamaterial models, is demonstrated analytically and applied to case studies. The relevance of the connection in the aeroacoustic field is discussed along with the consequent computational advantages for numerical simulations. This is exploited to perform a simulation-based design optimization of a phase-graded metasurface acoustic lining of a 2 D duct in presence of flow. Results show promising abilities of the optimized device to modify and control the directivity of the noise emitted from the duct by means of unconventional reflections. The noise reduction in the desired direction is obtained through constructive and destructive interference, with no absorption from the boundaries.
5
Palma, Giorgio, Lorenzo Burghignoli, Francesco Centracchio e Umberto Iemma. "Innovative Acoustic Treatments of Nacelle Intakes Based on Optimised Metamaterials". Aerospace 8, n. 10 (14 ottobre 2021): 296. http://dx.doi.org/10.3390/aerospace8100296.
Abstract (sommario):
Modern turbofans with high bypass ratios, low blade passage frequencies and short nacelles require continuous development of acoustic linings to achieve the noise reductions expected by the international aviation authorities. Metamaterials and metafluids have been recently proposed as promising technologies for designing innovative acoustic treatments dedicated to reducing aeronautic turbofan noise emissions. In this work, a phase-gradient metasurface treatment is investigated as a way to tackle the noise radiation from an axially symmetric nacelle. This paper aims to study the potential benefits of the mentioned technology, and is not an attempt to design a complete new liner or nacelle. The metasurface is modelled through an equivalent metafluid, and a simulation-based optimisation is used in defining the design parameters. The tonal contribution of the blade passage frequency is considered, and the numerical results with the metafluid optimised on one azimuthal mode at a time show a significant effect in terms of acoustic levels and directivity over an arc of virtual receivers.
6
Talero, Gabriel, Camilo Bayona-Roa, Vladimir Silva, Manuel Mayorga, Juan Pava e Mauricio Lopez. "Biodiesel substitution in a J69 aeronautic turbine engine: An experimental assessment of the effects on energy efficiency, technical performance and emissions". Sustainable Energy Technologies and Assessments 40 (agosto 2020): 100746. http://dx.doi.org/10.1016/j.seta.2020.100746.
7
Zaccaria, Valentina, Amare D. Fentaye, Mikael Stenfelt e Konstantinos G. Kyprianidis. "Probabilistic Model for Aero-Engines Fleet Condition Monitoring". Aerospace 7, n. 6 (26 maggio 2020): 66. http://dx.doi.org/10.3390/aerospace7060066.
Abstract (sommario):
Since aeronautic transportation is responsible for a rising share of polluting emissions, it is of primary importance to minimize the fuel consumption any time during operations. From this perspective, continuous monitoring of engine performance is essential to implement proper corrective actions and avoid excessive fuel consumption due to engine deterioration. This requires, however, automated systems for diagnostics and decision support, which should be able to handle large amounts of data and ensure reliability in all the multiple conditions the engines of a fleet can be found in. In particular, the proposed solution should be robust to engine-to-engine deviations and different sensors availability scenarios. In this paper, a probabilistic Bayesian network for fault detection and identification is applied to a fleet of engines, simulated by an adaptive performance model. The combination of the performance model and the Bayesian network is also studied and compared to the probabilistic model only. The benefit in the suggested hybrid approach is identified as up to 50% higher accuracy. Sensors unavailability due to manufacturing constraints or sensor faults reduce the accuracy of the physics-based method, whereas the Bayesian model is less affected.
8
Amoroso, Francesco, Angelo De Fenza, Giuseppe Petrone e Rosario Pecora. "A Sensitivity Analysis on the Influence of the External Constraints on the Dynamic Behaviour of a Low Pollutant Emissions Aircraft Combustor-Rig". Archive of Mechanical Engineering 63, n. 3 (1 settembre 2016): 435–54. http://dx.doi.org/10.1515/meceng-2016-0025.
Abstract (sommario):
Abstract The need to reduce pollutant emissions leads the engineers to design new aeronautic combustors characterized by lean burn at relatively low temperatures. This requirement can easily cause flame instability phenomena and consequent pressure pulsations which may seriously damage combustor’s structure and/or compromise its fatigue life. Hence the need to study the combustor’s structural dynamics and the interaction between elastic, thermal and acoustic phenomena. Finite element method represent a largely used and fairly reliable tool to address these studies; on the other hand, the idealization process may bring to results quite far from the reality whereas too simplifying assumptions are made. Constraints modelling represent a key-issue for all dynamic FE analyses; a wrong simulation of the constraints may indeed compromise entire analyses although running on very accurate and mesh-refined structural models. In this paper, a probabilistic approach to characterize the influence of external constraints on the modal behaviour of an aircraft combustor-rig is presented. The finite element model validation was performed at first by comparing numerical and experimental results for the free-free condition (no constraints). Once the model was validated, the effect of constraints elasticity on natural frequencies was investigated by means of a probabilistic design simulation (PDS); referring to a specific tool developed in the ANSYS®software, a preliminary statistical analysis was at performed via Monte-Carlo Simulation (MCS) method. The results were then correlated with the experimental ones via Response Surface Method (RSM).
9
Hashmi, Nauman Ehsan, e Atif Manzoor. "International Aeronautical Emission". International Journal of Aviation Technology, Engineering and Management 1, n. 1 (gennaio 2011): 30–36. http://dx.doi.org/10.4018/ijatem.2011010103.
Abstract (sommario):
The aviation sector is one the modern innovations in recent times. According to the Federal Aviation Authority (2005, p. 1) in 1903 the world population was estimated to be 1.6 billion, while presently the same number of people use aviation industry as mode of travel. The industry also provides around 28 million jobs and carries 40% of world carriage. But with growing concerns on environmental health, the aviation sector has signifcant impact on the environment. These contributions are in the form of noise and atmospheric emission. In this paper, the authors examine aviation emission and its mitigation straetgy adopted by the European Union (EU).
10
Langat, Rogers K., Emmanuel De Luycker, Arthur Cantarel e Micky Rakotondrabe. "Integration Technology with Thin Films Co-Fabricated in Laminated Composite Structures for Defect Detection and Damage Monitoring". Micromachines 15, n. 2 (15 febbraio 2024): 274. http://dx.doi.org/10.3390/mi15020274.
Abstract (sommario):
Despite the well-established nature of non-destructive testing (NDT) technologies, autonomous monitoring systems are still in high demand. The solution lies in harnessing the potential of intelligent structures, particularly in industries like aeronautics. Substantial downtime occurs due to routine maintenance, leading to lost revenue when aircraft are grounded for inspection and repairs. This article explores an innovative approach using intelligent materials to enhance condition-based maintenance, ultimately cutting life-cycle costs. The study emphasizes a paradigm shift toward structural health monitoring (SHM), utilizing embedded sensors for real-time monitoring. Active thin film piezoelectric materials are proposed for their integration into composite structures. The work evaluates passive sensing through acoustic emission (AE) signals and active sensing using Lamb wave propagation, presenting amplitude-based and frequency domain approaches for damage detection. A comprehensive signal processing approach is presented, and the damage index and damage size correlation function are introduced to enable continuous monitoring due to their sensitivity to changes in material properties and defect severity. Additionally, finite element modeling and experimental validation are proposed to enhance their understanding and applicability. This research contributes to developing more efficient and cost-effective aircraft maintenance approaches through SHM, addressing the competitive demands of the aeronautic industry.
11
Sharma, Dhananjay, Dr Virendra Pathak e Amarendra Singh. "The Role of Biomass Burning Emission in Indo-Gangetic Plains on the Air Quality". International Journal for Research in Applied Science and Engineering Technology 10, n. 9 (30 settembre 2022): 926–32. http://dx.doi.org/10.22214/ijraset.2022.46766.
Abstract (sommario):
Abstract: Every year, the Indo-Gangetic Plains (IGP) burn biomass, which results in serious atmospheric pollution, including reactive nitrogen. This study focuses on the burning of biomass area and nitrogen species emissions in the months of October, November, and March, April, and May from 2016 to 2020. Using a satellite product from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on the National Aeronautics and Space Administration (NASA) Aqua and Terra satellites, reactive nitrogen species emissions (ammonia (NH3), nitrous oxide (N2O), and oxides of nitrogen (NOx = NO + NO2)) were estimated for the study period. In this study, region of IGP is divided in three parts i.e. West IGP region, Middle IGP region and East IGP region. we estimate that post-monsoon west IGP region has highest average burned area is 19731.081839 sq km and the maximum emission of nitrogen species NH3 is 3558462491 g in year 2016. Our findings on biomass burning and nitrogen species emissions offer important insight for addressing the most contaminated area of the IGP region.
12
Domínguez-Martínez, Jorge, Jesús López-Sánchez, Federico García-Galván, Aída Serrano, Violeta Barranco, Juan Carlos Galván, Óscar Rodríguez de la Fuente e Noemí Carmona. "Eco-Friendly Sol–Gel Coatings with Organic Corrosion Inhibitors for Lightweight AZ61 Alloy". Gels 10, n. 3 (27 febbraio 2024): 168. http://dx.doi.org/10.3390/gels10030168.
Abstract (sommario):
The latest advances in technology and materials science have catalyzed a transformative shift towards the adoption of environmentally conscious and lightweight materials across key sectors such as aeronautics, biomedical, and automotive industries. Noteworthy among these innovations are the magnesium-aluminum (Mg-Al) alloys employed in aeronautical applications, contributing to the overall reduction in aircraft weight and subsequently diminishing fuel consumption and mitigating atmospheric emissions. The present work delves into a study of the anti-corrosive properties inherent in various sol-gel coatings, leveraging a range of environmentally friendly corrosion inhibitors, specifically tailored for samples of the AZ61 alloy. Methodologically, the work involves the synthesis and application of sol-gel coatings on AZ61 alloy containing eco-friendly inhibitors: L-cysteine, N-acetyl-cysteine, curcumin and methylene blue. Subsequently, an accelerated corrosion test in a simulated saline environment is performed. Through microstructural and compositional analyses, the best inhibitors responses are achieved with inhibitors containing S, N heteroatoms and conjugated double bonds in their structure, probably due to the creation of a continuous MgCl2 layer. This research contributes to the ongoing discourse on protective eco-coatings, aligning with the broader paradigm shift towards sustainable and lightweight materials in key industries.
13
Sun, Xiaohuan, Soheil Jafari, Seyed Alireza Miran Fashandi e Theoklis Nikolaidis. "Compressor Degradation Management Strategies for Gas Turbine Aero-Engine Controller Design". Energies 14, n. 18 (10 settembre 2021): 5711. http://dx.doi.org/10.3390/en14185711.
Abstract (sommario):
The Advisory Council for Aeronautics Research in Europe (ACARE) Flight Path 2050 focuses on ambitious and severe targets for the next generation of air travel systems (e.g., 75% reduction in CO2 emissions per passenger kilometre, a 90% reduction in NOx emissions, and a 65% reduction in the noise emissions of flying aircraft relative to the capabilities of typical new aircraft in 2000). Degradation is an inevitable phenomenon as aero-engines age with significant impacts on the engine performance, emissions level, and fuel consumption. The engine control system is a key element capable of coping with degradation consequences subject to the implementation of an advanced management strategy. This paper demonstrates a methodological approach for aero-engine controller adjustment to deal with degradation implications, such as emission levels and increased fuel consumption. For this purpose, a component level model for an aero-engine was first built and transformed to a block-structured Wiener model using a system identification approach. An industrial Min-Max control strategy was then developed to satisfy the steady state and transient limit protection requirements simultaneously while satisfying the physical limitation control modes, such as over-speed, surge, and over-temperature. Next, the effects of degradation on the engine performance and associated changes to the controller were analysed thoroughly to propose practical degradation management strategies based on a comprehensive scientometric analysis of the topic. The simulation results show that the proposed strategy was effective in restoring the degraded engine performance to the level of the clean engine while protecting the engine from physical limitations. The proposed adjustments in the control strategy reduced the fuel consumption and, as a result, the emission level and carbon footprint of the engine.
14
Milu-Vaidesegan, S., M. Orain, P. Doublet e M. Bellenoue. "Study Of Flame-Wall Interaction : Influence Of Effusion Cooling On Pollutant Emissions". Proceedings of the International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics 20 (11 luglio 2022): 1–14. http://dx.doi.org/10.55037/lxlaser.20th.99.
Abstract (sommario):
For several years, engine manufacturers have had to meet increasingly stringent standards on pollutant emissions. Studying the flame/wall interaction is essential to control pollutant emissions and extend the lifetime of gas turbine. An inherent constraint of combustion chambers is that the walls are cooled by air introduced through multi-perforation (effusion cooling). The problem is that this injection of cold air into the combustion chamber disrupts the oxidation reactions of the fuel either by freezing them, which yields the emission of large quantities of CO, UHC and soot or by bringing fresh air to the rich areas, which is very favourable to the formation of thermal NOx. The focus of this work is to investigate the influence of parameters such as burner flow rate, cooling flow rate and equivalence ratio on the reaction zone. Experiments were conducted with a multi-perforated plate placed above a flat flame burner to simulate the head-on interaction between an aeronautical injector and an effusion cooled liner.
15
Pietreanu, Casandra Venera, Sorin Eugen Zaharia e Cornel Dinu. "Quantification of the Impact on the Environment of Romanian National Airlines". Revista de Chimie 70, n. 4 (15 maggio 2019): 1485–89. http://dx.doi.org/10.37358/rc.19.4.7155.
Abstract (sommario):
Air quality is submitted to national and international standards and regulations, thus air traffic growth�s implications on the environment can be analyzed only in compliance with such norms. While achieving the requirements of environmental protection reflected by legal frameworks, airlines have to establish their own responsibility policy based on emission reduction options, which can be approached by market strategies and technological developments. In this context, the paper aims at analyzing this long-term challenge for the Romanian aeronautical industry and assesses airlines� strategies and targets. The research also aims to quantify the impact on the environment of domestic flights performed by two national airlines (i.e. Tarom and Blue Air) on a peak period in terms of air traffic, with accent on the emissions of and(which represents a linear function of fuel burn).
16
Puga, Hélder. "Casting and Forming of Advanced Aluminum Alloys". Metals 10, n. 4 (9 aprile 2020): 494. http://dx.doi.org/10.3390/met10040494.
17
Liu, Junhua, Jose M. Rodriguez, Stephen D. Steenrod, Anne R. Douglass, Jennifer A. Logan, Mark A. Olsen, Krzysztof Wargan e Jerald R. Ziemke. "Causes of interannual variability over the southern hemispheric tropospheric ozone maximum". Atmospheric Chemistry and Physics 17, n. 5 (7 marzo 2017): 3279–99. http://dx.doi.org/10.5194/acp-17-3279-2017.
Abstract (sommario):
Abstract. We examine the relative contribution of processes controlling the interannual variability (IAV) of tropospheric ozone over four sub-regions of the southern hemispheric tropospheric ozone maximum (SHTOM) over a 20-year period. Our study is based on hindcast simulations from the National Aeronautics and Space Administration Global Modeling Initiative chemistry transport model (NASA GMI-CTM) of tropospheric and stratospheric chemistry, driven by assimilated Modern Era Retrospective Analysis for Research and Applications (MERRA) meteorological fields. Our analysis shows that over SHTOM region, the IAV of the stratospheric contribution is the most important factor driving the IAV of upper tropospheric ozone (270 hPa), where ozone has a strong radiative effect. Over the South Atlantic region, the contribution from surface emissions to the IAV of ozone exceeds that from stratospheric input at and below 430 hPa. Over the South Indian Ocean, the IAV of stratospheric ozone makes the largest contribution to the IAV of ozone with little or no influence from surface emissions at 270 and 430 hPa in austral winter. Over the tropical South Atlantic region, the contribution from IAV of stratospheric input dominates in austral winter at 270 hPa and drops to less than half but is still significant at 430 hPa. Emission contributions are not significant at these two levels. The IAV of lightning over this region also contributes to the IAV of ozone in September and December. Over the tropical southeastern Pacific, the contribution of the IAV of stratospheric input is significant at 270 and 430 hPa in austral winter, and emissions have little influence.
18
Mónico Muñoz, Luisa Fernanda, Juan José Sandoval Sotelo e Andrés Felipe Rodríguez Chaparro. "Estudio Teórico de la Influencia del Uso de Mezclas de Biodiesel de Aceite de Palma con JET a-1 en Motores a Reacción". Ingeniería 22, n. 1 (21 febbraio 2017): 98. http://dx.doi.org/10.14483/udistrital.jour.reving.2017.1.a06.
Abstract (sommario):
Context: like many others, today the aeronautical industry has been forced to implement methods to mitigate the damage produced to the environment due to the emission of polluting gases and in doing so, confront the problem of global warming. In this context, research on the use of alternative fuels is of paramount importance, in particular the study of engine performance when using blends of Colombian Biodiesel based on palm oil with Jet A1.Method: as a starting point, we made a review of the state of the art so as to select which engine to study and then the alternative fuels to be used. Simultaneously, Colombian biodiesel based on palm oil was selected, as it has been shown to be a fuel with good performance when it is blended in percentages of 10%, 20% and 50%. Each of the blends were tested in the laboratory to obtain their viscosity, density and calorific values. A spreadsheet program was developed to conduct the analysis, which contemplated the physical properties of mixtures and engine parameters, as well as emissions of nitrous oxides (NOx), atomization and combustion produced by the use of mixtures. The results were compared against those of the Gasturbine simulation softwareResults: CFM 56-5B was chosen as the appropriate engine for the study, because it is currently the most used in the Colombian aeronautical industry. On the other hand, none of the alternative fuel blends generates the same engine performance when using Jet A1. The blends E10 and E20 have a similar behavior, with the novelty of generating less amount of NOx emissions and improving the atomization of the fuel.Conclusions: When the engine’s performance with conventional fuel is comparing with Biodiesel mixtures, a decrease of the thrust is produced as the percentage of Biodiesel in the mixture increases. Because the mixtures of alternative fuel have a lower calorific value fuel consumption in these cases is always greater. However, when comparing the NOx levels produced, a decrease of this pollutant is observed when using Biodiesel blends. It is worth noting that it is of great interest for future work to evaluate other pollutant emissions and, in turn, the behavior of other types of Biodiesel in jet engines.Language: Spanish.
19
Murrieta-Mendoza, A., e R. M. Botez. "New method to compute the missed approach fuel consumption and its emissions". Aeronautical Journal 120, n. 1228 (10 maggio 2016): 910–29. http://dx.doi.org/10.1017/aer.2016.37.
Abstract (sommario):
ABSTRACTThe aeronautical industry has set for itself important environmental goals, creating the need of improved tools for measuring the polluting emissions generated by fuel burn. This paper describes a new method to estimate the fuel burn and the pollution generated by a landing approach and also for a missed approach procedure. Fuel emission estimations can be used to compare the costs of different routes. The method developed in this paper uses the Emissions Guide Book developed by the European Environment Agency as the needed database for the computations. This method gives estimations of the fuel burn and emissions, including the amounts of CO, NOx, HC, EICO, EINOx and EIHC for a given flight as its output. The flight computation is divided into two sections: one section for the aircraft's travelled distance and a second section for the time an aircraft flies under certain flight modes. Since this method computes the missed approach fuel and emissions contribution, it computes the burn for a given descent approach for a successful landing, as well as for the same descent approach with a missed approach procedure followed by a successful landing. These two landings are verified in a complete flight to study the missed approach contribution for a conventional mid-range flight. The results show that a descent with the missed approach procedure requires 5.7 times more fuel than a normal, successful descent. This extra fuel burn increases the pollution released to the atmosphere and would impact the airlines’ profit margin due to the added fuel costs and longer flight times, as well as any future economic measures imposed on the increased air and noise pollution.
20
MILOUDI, Houcine, Mohamed MILOUDI, Mohammed Hamza BERMAKI, Abdelkader GOURBI e Abdelber BENDAOUD. "Optimization of EMC Filter for a Variable Speed Drive System in Electric Aircraft". Eurasia Proceedings of Science Technology Engineering and Mathematics 26 (30 dicembre 2023): 60–66. http://dx.doi.org/10.55549/epstem.1409311.
Abstract (sommario):
In recent years, static converters are in constant evolution, and they have occupied an increasing role within aeronautical on-board networks. This development results in an increase in the power density of the onboard network and a reduction in the volume of the components. This development in electrical technologies creates problems related to electromagnetic pollution. To avoid polluting their environments, the power electronics designer will have to provide effective devices and means to mitigate the levels of emissions from their equipment. This work focuses on electromagnetic compatibility (EMC) problems appearing in power converters on board future more electric aircraft. The work deals with the aircraft EMC issue, and then the reduction of electromagnetic pollution from a variable speed drive system. With the standards used in the aeronautical fields, type DO 160D, the optimization approach consists in bringing the level of emissions of the current generated towards the network and the load Induction motor) below the EMC standard in the whole range of frequencies 150 kHz -30 MHz.
21
Valdés, Rosa Maria Arnaldo, Victor Fernando Gomez Comendador e Luis Manuel Braga Campos. "How Much Can Carbon Taxes Contribute to Aviation Decarbonization by 2050". Sustainability 13, n. 3 (21 gennaio 2021): 1086. http://dx.doi.org/10.3390/su13031086.
Abstract (sommario):
Aviation emissions from 2016 to 2050 could consume between 12% and 27% of the remaining carbon budget to keep global temperature rise below 1.5 °C above preindustrial levels. Consequently, aviation is being challenged to immediately start to reduce its in-sector emissions, then sharply reduce its CO2 emissions and fully decarbonize toward the second half of this century. Among the analyses carried out within the Horizon 2020 project PARE—Perspectives for Aeronautical Research in Europe, this paper tackles the potential role of climate change levy schemes in achieving the ambitious objective of aviation decarbonization by the year 2050.
22
Marqué, Christophe, Karl-Ludwig Klein, Christian Monstein, Hermann Opgenoorth, Antti Pulkkinen, Stephan Buchert, Säm Krucker, Rudiger Van Hoof e Peter Thulesen. "Solar radio emission as a disturbance of aeronautical radionavigation". Journal of Space Weather and Space Climate 8 (2018): A42. http://dx.doi.org/10.1051/swsc/2018029.
Abstract (sommario):
On November 4th, 2015 secondary air traffic control radar was strongly disturbed in Sweden and some other European countries. The disturbances occurred when the radar antennas were pointing at the Sun. In this paper, we show that the disturbances coincided with the time of peaks of an exceptionally strong (∼105 Solar Flux Units) solar radio burst in a relatively narrow frequency range around 1 GHz. This indicates that this radio burst is the most probable space weather candidate for explaining the radar disturbances. The dynamic radio spectrum shows that the high flux densities are not due to synchrotron emission of energetic electrons, but to coherent emission processes, which produce a large variety of rapidly varying short bursts (such as pulsations, fiber bursts, and zebra patterns). The radio burst occurs outside the impulsive phase of the associated flare, about 30 min after the soft X-ray peak, and it is temporarily associated with fast evolving activity occurring in strong solar magnetic fields. While the relationship with strong magnetic fields and the coherent spectral nature of the radio burst provide hints towards the physical processes which generate such disturbances, we have so far no means to forecast them. Well-calibrated monitoring instruments of whole Sun radio fluxes covering the UHF band could at least provide a real-time identification of the origin of such disturbances, which reports in the literature show to also affect GPS signal reception.
23
Evangeliou, N., Y. Balkanski, W. M. Hao, A. Petkov, R. P. Silverstein, R. Corley, B. L. Nordgren et al. "Wildfires in northern Eurasia affect the budget of black carbon in the Arctic – a 12-year retrospective synopsis (2002–2013)". Atmospheric Chemistry and Physics 16, n. 12 (21 giugno 2016): 7587–604. http://dx.doi.org/10.5194/acp-16-7587-2016.
Abstract (sommario):
Abstract. In recent decades much attention has been given to the Arctic environment, where climate change is happening rapidly. Black carbon (BC) has been shown to be a major component of Arctic pollution that also affects the radiative balance. In the present study, we focused on how vegetation fires that occurred in northern Eurasia during the period of 2002–2013 influenced the budget of BC in the Arctic. For simulating the transport of fire emissions from northern Eurasia to the Arctic, we adopted BC fire emission estimates developed independently by GFED3 (Global Fire Emissions Database) and FEI-NE (Fire Emission Inventory – northern Eurasia). Both datasets were based on fire locations and burned areas detected by MODIS (Moderate resolution Imaging Spectroradiometer) instruments on NASA's (National Aeronautics and Space Administration) Terra and Aqua satellites. Anthropogenic sources of BC were adopted from the MACCity (Monitoring Atmospheric Composition and Climate and megacity Zoom for the Environment) emission inventory.During the 12-year period, an average area of 250 000 km2 yr−1 was burned in northern Eurasia (FEI-NE) and the global emissions of BC ranged between 8.0 and 9.5 Tg yr−1 (FEI-NE+MACCity). For the BC emitted in the Northern Hemisphere (based on FEI-NE+MACCity), about 70 % originated from anthropogenic sources and the rest from biomass burning (BB). Using the FEI-NE+MACCity inventory, we found that 102 ± 29 kt yr−1 BC was deposited in the Arctic (defined here as the area north of 67° N) during the 12 years simulated, which was twice as much as when using the MACCity inventory (56 ± 8 kt yr−1). The annual mass of BC deposited in the Arctic from all sources (FEI-NE in northern Eurasia, MACCity elsewhere) is significantly higher by about 37 % in 2009 (78 vs. 57 kt yr−1) to 181 % in 2012 (153 vs. 54 kt yr−1), compared to the BC deposited using just the MACCity emission inventory. Deposition of BC in the Arctic from BB sources in the Northern Hemisphere thus represents 68 % of the BC deposited from all BC sources (the remaining being due to anthropogenic sources). Northern Eurasian vegetation fires (FEI-NE) contributed 85 % (79–91 %) to the BC deposited over the Arctic from all BB sources in the Northern Hemisphere.We estimate that about 46 % of the BC deposited over the Arctic from vegetation fires in northern Eurasia originated from Siberia, 6 % from Kazakhstan, 5 % from Europe, and about 1 % from Mongolia. The remaining 42 % originated from other areas in northern Eurasia. About 42 % of the BC released from northern Eurasian vegetation fires was deposited over the Arctic (annual average: 17 %) during spring and summer.
24
Souri, Amir H., Caroline R. Nowlan, Gonzalo González Abad, Lei Zhu, Donald R. Blake, Alan Fried, Andrew J. Weinheimer et al. "An inversion of NO<sub><i>x</i></sub> and non-methane volatile organic compound (NMVOC) emissions using satellite observations during the KORUS-AQ campaign and implications for surface ozone over East Asia". Atmospheric Chemistry and Physics 20, n. 16 (24 agosto 2020): 9837–54. http://dx.doi.org/10.5194/acp-20-9837-2020.
Abstract (sommario):
Abstract. The absence of up-to-date emissions has been a major impediment to accurately simulating aspects of atmospheric chemistry and to precisely quantifying the impact of changes in emissions on air pollution. Hence, a nonlinear joint analytical inversion (Gauss–Newton method) of both volatile organic compounds (VOCs) and nitrogen oxide (NOx) emissions is made by exploiting the Smithsonian Astrophysical Observatory (SAO) Ozone Mapping and Profiler Suite Nadir Mapper (OMPS-NM) formaldehyde (HCHO) and the National Aeronautics and Space Administration (NASA) Ozone Monitoring Instrument (OMI) tropospheric nitrogen dioxide (NO2) columns during the Korea–United States Air Quality (KORUS-AQ) campaign over East Asia in May–June 2016. Effects of the chemical feedback of NOx and VOCs on both NO2 and HCHO are implicitly included by iteratively optimizing the inversion. Emission uncertainties are greatly narrowed (averaging kernels > 0.8, which is the mathematical presentation of the partition of information gained from the satellite observations with respect to the prior knowledge) over medium- to high-emitting areas such as cities and dense vegetation. The prior amount of total NOx emissions is mainly dictated by values reported in the MIX-Asia 2010 inventory. After the inversion we conclude that there is a decline in emissions (before, after, change) for China (87.94±44.09 Gg d−1, 68.00±15.94 Gg d−1, −23 %), North China Plain (NCP) (27.96±13.49 Gg d−1, 19.05±2.50 Gg d−1, −32 %), Pearl River Delta (PRD) (4.23±1.78 Gg d−1, 2.70±0.32 Gg d−1, −36 %), Yangtze River Delta (YRD) (9.84±4.68 Gg d−1, 5.77±0.51 Gg d−1, −41 %), Taiwan (1.26±0.57 Gg d−1, 0.97±0.33 Gg d−1, −23 %), and Malaysia (2.89±2.77 Gg d−1, 2.25±1.34 Gg d−1, −22 %), all of which have effectively implemented various stringent regulations. In contrast, South Korea (2.71±1.34 Gg d−1, 2.95±0.58 Gg d−1, +9 %) and Japan (3.53±1.71 Gg d−1, 3.96±1.04 Gg d−1, +12 %) are experiencing an increase in NOx emissions, potentially due to an increased number of diesel vehicles and new thermal power plants. We revisit the well-documented positive bias (by a factor of 2 to 3) of MEGAN v2.1 (Model of Emissions of Gases and Aerosols from Nature) in terms of biogenic VOC emissions in the tropics. The inversion, however, suggests a larger growth of VOCs (mainly anthropogenic) over NCP (25 %) than previously reported (6 %) relative to 2010. The spatial variation in both the magnitude and sign of NOx and VOC emissions results in nonlinear responses of ozone production and loss. Due to a simultaneous decrease and increase in NOx∕VOC over NCP and YRD, we observe a ∼53 % reduction in the ratio of the chemical loss of NOx (LNOx) to the chemical loss of ROx (RO2+HO2) over the surface transitioning toward NOx-sensitive regimes, which in turn reduces and increases the afternoon chemical loss and production of ozone through NO2+OH (−0.42 ppbv h−1)∕HO2 (and RO2)+NO (+0.31 ppbv h−1). Conversely, a combined decrease in NOx and VOC emissions in Taiwan, Malaysia, and southern China suppresses the formation of ozone. Simulations using the updated emissions indicate increases in maximum daily 8 h average (MDA8) surface ozone over China (0.62 ppbv), NCP (4.56 ppbv), and YRD (5.25 ppbv), suggesting that emission control strategies on VOCs should be prioritized to curb ozone production rates in these regions. Taiwan, Malaysia, and PRD stand out as regions undergoing lower MDA8 ozone levels resulting from the NOx reductions occurring predominantly in NOx-sensitive regimes.
25
Sirisingha, Sittha, Theppitak Klueameephol e Piyawit Mangmool. "Blue Earth Innovation Reduce Emission of Aircraft". Journal Of Technical Education Development 35, n. 125 (4 marzo 2023): 3–10. http://dx.doi.org/10.14416/j.ted.2023.02.002.
Abstract (sommario):
This academic paper focuses on the future of clean energy that will be used to propel aircraft in the future. The new type of clean energy will have significant positive impact on the environment as the current source of fuel generated from aircraft engine and from the aerospace industry. This study serves to promote awareness and to inspire research and development of new energy alternatives that can be utilized in the aerospace industry with the intention of reducing pollution. The resulting pollution emitted by aircraft engine during flight contributes to the higher year on year overall global temperature and the changes in seasonality from years before are causes for concern and the aerospace industry should take to heart the significance of impact that air travel has on the global environment. It is therefore very important for the major players in the aeronautical industry to take action to find ways to cut emissions to lower environmental impact. This means that manufacturers and engineers need to rethink their design and material use to enable the aeronautical industry to be more environmentally friendly which means innovative use of alternative sources of fuel or clean energy such as electric or hybrid engines while vehicles used in the airports should also be changed from combustion to electric. This will have a positive impact on the environment within the airport and the environment in general going forward. Improve engine performance and/or alternative fuel, aircraft parts to lower weight and thus pollution, airports must have ways to better manage traffic to improve fuel efficiency of aircraft.
26
French, Nancy H. F., Donald McKenzie, Tyler Erickson, Benjamin Koziol, Michael Billmire, K. Arthur Endsley, Naomi K. Yager Scheinerman et al. "Modeling Regional-Scale Wildland Fire Emissions with the Wildland Fire Emissions Information System*". Earth Interactions 18, n. 16 (1 settembre 2014): 1–26. http://dx.doi.org/10.1175/ei-d-14-0002.1.
Abstract (sommario):
Abstract As carbon modeling tools become more comprehensive, spatial data are needed to improve quantitative maps of carbon emissions from fire. The Wildland Fire Emissions Information System (WFEIS) provides mapped estimates of carbon emissions from historical forest fires in the United States through a web browser. WFEIS improves access to data and provides a consistent approach to estimating emissions at landscape, regional, and continental scales. The system taps into data and tools developed by the U.S. Forest Service to describe fuels, fuel loadings, and fuel consumption and merges information from the U.S. Geological Survey (USGS) and National Aeronautics and Space Administration on fire location and timing. Currently, WFEIS provides web access to Moderate Resolution Imaging Spectroradiometer (MODIS) burned area for North America and U.S. fire-perimeter maps from the Monitoring Trends in Burn Severity products from the USGS, overlays them on 1-km fuel maps for the United States, and calculates fuel consumption and emissions with an open-source version of the Consume model. Mapped fuel moisture is derived from daily meteorological data from remote automated weather stations. In addition to tabular output results, WFEIS produces multiple vector and raster formats. This paper provides an overview of the WFEIS system, including the web-based system functionality and datasets used for emissions estimates. WFEIS operates on the web and is built using open-source software components that work with open international standards such as keyhole markup language (KML). Examples of emissions outputs from WFEIS are presented showing that the system provides results that vary widely across the many ecosystems of North America and are consistent with previous emissions modeling estimates and products.
27
Moevus, M., Pascal Reynaud, M. R'Mili, N. Godin, Dominique Rouby e Gilbert Fantozzi. "Static Fatigue of a 2.5D SiC/[Si-B-C] Composite at Intermediate Temperature under Air". Advances in Science and Technology 50 (ottobre 2006): 141–46. http://dx.doi.org/10.4028/www.scientific.net/ast.50.141.
Abstract (sommario):
Non-oxide ceramic-matrix composites (CMCs) are subjected to be used in aeronautic applications which require very long duration (up to 100 000h) of materials at high temperatures and under air. Recently a self-healing [Si-B-C] matrix has been developped to enhance strongly the lifetime of CMCs under air. The aim of this work is to study the mechanical behaviour of a SiCf/[Si-B-C] composite with a self-healing matrix under static fatigue, and to determine its lifetime. During the mechanical tests, acoustic emission is detected in order to characterize the damage of the composite in addition to the measurement of the longitudinal deformation of the composite. The analysis of acoustic emission follows a non-supervised procedure of classification. Each event of acoustic emission is described by a set of several parameters, and the total activity can be divided in four classes. The assignment of each class to a damage mechanism is required to follow the spread of damage during fatigue and to determine the mechanisms controlling the failure of the composite.
28
Huang, Min, James H. Crawford, Joshua P. DiGangi, Gregory R. Carmichael, Kevin W. Bowman, Sujay V. Kumar e Xiwu Zhan. "Satellite soil moisture data assimilation impacts on modeling weather variables and ozone in the southeastern US – Part 1: An overview". Atmospheric Chemistry and Physics 21, n. 14 (21 luglio 2021): 11013–40. http://dx.doi.org/10.5194/acp-21-11013-2021.
Abstract (sommario):
Abstract. This study evaluates the impact of satellite soil moisture (SM) data assimilation (DA) on regional weather and ozone (O3) modeling over the southeastern US during the summer. Satellite SM data are assimilated into the Noah land surface model using an ensemble Kalman filter approach within National Aeronautics and Space Administration's Land Information System framework, which is semicoupled with the Weather Research and Forecasting model with online Chemistry (WRF-Chem; standard version 3.9.1.1). The DA impacts on the model performance of SM, weather states, and energy fluxes show strong spatiotemporal variability. Dense vegetation and water use from human activities unaccounted for in the modeling system are among the factors impacting the effectiveness of the DA. The daytime surface O3 responses to the DA can largely be explained by the temperature-driven changes in biogenic emissions of volatile organic compounds and soil nitric oxide, chemical reaction rates, and dry deposition velocities. On a near-biweekly timescale, the DA modified the mean daytime and daily maximum 8 h average surface O3 by up to 2–3 ppbv, with the maximum impacts occurring in areas where daytime surface air temperature most strongly (i.e., by ∼2 K) responded to the DA. The DA impacted WRF-Chem upper tropospheric O3 (e.g., for its daytime-mean, by up to 1–1.5 ppbv) partially via altering the transport of O3 and its precursors from other places as well as in situ chemical production of O3 from lightning and other emissions. Case studies during airborne field campaigns suggest that the DA improved the model treatment of convective transport and/or lightning production. In the cases that the DA improved the modeled SM, weather fields, and some O3-related processes, its influences on the model's O3 performance at various altitudes are not always as desirable. This is in part due to the uncertainty in the model's key chemical inputs, such as anthropogenic emissions, and the model representation of stratosphere–troposphere exchanges. This can also be attributable to shortcomings in model parameterizations (e.g., chemical mechanism, natural emission, photolysis and deposition schemes), including those related to representing water availability impacts. This study also shows that the WRF-Chem upper tropospheric O3 response to the DA has comparable magnitudes with its response to the estimated US anthropogenic emission changes within 2 years. As reductions in anthropogenic emissions in North America would benefit the mitigation of O3 pollution in its downwind regions, this analysis highlights the important role of SM in quantifying air pollutants' source–receptor relationships between the US and its downwind areas. It also emphasizes that using up-to-date anthropogenic emissions is necessary for accurately assessing the DA impacts on the model performance of O3 and other pollutants over a broad region. This work will be followed by a Noah-Multiparameterization (with dynamic vegetation)-based study over the southeastern US, in which selected processes including photosynthesis and O3 dry deposition will be the foci.
29
Mohammadi Doulabi Fard, Seyed Jalal, e Soheil Jafari. "Fuzzy Controller Structures Investigation for Future Gas Turbine Aero-Engines". International Journal of Turbomachinery, Propulsion and Power 6, n. 1 (22 febbraio 2021): 2. http://dx.doi.org/10.3390/ijtpp6010002.
Abstract (sommario):
The Advisory Council for Aeronautics Research in Europe (ACARE) Flight Path 2050 focuses on ambitious and severe targets for the next generation of air travel systems (e.g., 75% reduction in CO2 emissions per passenger kilometer, a 90% reduction in NOx emissions, and 65% reduction in noise emission of flying aircraft relative to the capabilities of typical new aircraft in 2000). In order to meet these requirements, aircraft engines should work very close to their operating limits. Therefore, the importance of advanced control strategies to satisfy all engine control modes simultaneously while protecting them from malfunctions and physical damages is being more crucial these days. In the last three decades, fuzzy controllers (FCs) have been proposed as a high potential solution for performance improvement of the next generation of aircraft engines. Based on an analytic review, this paper divides the trend of FCs design into two main lines including pure FCs (PFC) and min–max FCs (MMFC). These two main architectures are then designed, implemented on hardware, and applied in a case study to analyze the advantages and disadvantages of each structure. The analysis of hardware-in-the-loop (HIL) simulation results shows that the pure FC structure would be a high potential candidate for maneuverability and response time indices improvement (e.g., military applications); while min–max FC architecture has a great potential for future civil aero-engines where the fuel consumption and steady-state responses are more important. The simulation results are also compared with those of industrial min–max controllers to confirm the feasibility and reliability of the fuzzy controllers for real-world application. The results of this paper propose a general roadmap for fuzzy controllers’ structure selection for new and next generation of aircraft engines.
30
Zhang, Q., D. G. Streets, G. R. Carmichael, K. He, H. Huo, A. Kannari, Z. Klimont et al. "Asian emissions in 2006 for the NASA INTEX-B mission". Atmospheric Chemistry and Physics Discussions 9, n. 1 (9 febbraio 2009): 4081–139. http://dx.doi.org/10.5194/acpd-9-4081-2009.
Abstract (sommario):
Abstract. A new inventory of air pollutant emissions in Asia in the year 2006 is developed to support the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B) funded by the National Aeronautics and Space Administration (NASA). Emissions are estimated for all major anthropogenic sources, excluding biomass burning. We estimate total Asian anthropogenic emissions in the year 2006 as follows: 47.1 Tg SO2, 36.7 Tg NOx, 298.2 Tg CO, 54.6 Tg NMVOC, 29.2 Tg PM10, 22.2 Tg PM2.5, 2.97 Tg BC, and 6.57 Tg OC. We emphasize emissions from China because they dominate the Asia pollutant outflow to the Pacific and the increase of emissions from China since 2000 is of great concern. We have implemented a~series of improved methodologies to gain a better understanding of emissions from China, including a detailed technology-based approach, a dynamic methodology representing rapid technology renewal, critical examination of energy statistics, and a new scheme of NMVOC speciation for model-ready emissions. We estimate China's anthropogenic emissions in the year 2006 to be as follows: 31.0 Tg SO2, 20.8 Tg NOx, 166.9 Tg CO, 23.2 Tg NMVOC, 18.2 Tg PM10, 13.3 Tg PM2.5, 1.8 Tg BC, and 3.2 Tg OC. We have also estimated 2001 emissions for China using the same methodology and found that all species show an increasing trend during 2001–2006: 36% increase for SO2, 55% for NOx, 18% for CO, 29% for VOC, 13% for PM10, and 14% for PM2.5, BC, and OC. Emissions are gridded at a resolution of 30 min×30 min and can be accessed at our web site (http://mic.greenresource.cn/intex-b2006).
31
Zhang, Q., D. G. Streets, G. R. Carmichael, K. B. He, H. Huo, A. Kannari, Z. Klimont et al. "Asian emissions in 2006 for the NASA INTEX-B mission". Atmospheric Chemistry and Physics 9, n. 14 (29 luglio 2009): 5131–53. http://dx.doi.org/10.5194/acp-9-5131-2009.
Abstract (sommario):
Abstract. A new inventory of air pollutant emissions in Asia in the year 2006 is developed to support the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B) funded by the National Aeronautics and Space Administration (NASA). Emissions are estimated for all major anthropogenic sources, excluding biomass burning. We estimate total Asian anthropogenic emissions in the year 2006 as follows: 47.1 Tg SO2, 36.7 Tg NOx, 298.2 Tg CO, 54.6 Tg NMVOC, 29.2 Tg PM10, 22.2 Tg PM2.5, 2.97 Tg BC, and 6.57 Tg OC. We emphasize emissions from China because they dominate the Asia pollutant outflow to the Pacific and the increase of emissions from China since 2000 is of great concern. We have implemented a series of improved methodologies to gain a better understanding of emissions from China, including a detailed technology-based approach, a dynamic methodology representing rapid technology renewal, critical examination of energy statistics, and a new scheme of NMVOC speciation for model-ready emissions. We estimate China's anthropogenic emissions in the year 2006 to be as follows: 31.0 Tg SO2, 20.8 Tg NOx, 166.9 Tg CO, 23.2 Tg NMVOC, 18.2 Tg PM10, 13.3 Tg PM2.5, 1.8 Tg BC, and 3.2 Tg OC. We have also estimated 2001 emissions for China using the same methodology and found that all species show an increasing trend during 2001–2006: 36% increase for SO2, 55% for NOx, 18% for CO, 29% for VOC, 13% for PM10, and 14% for PM2.5, BC, and OC. Emissions are gridded at a resolution of 30 min×30 min and can be accessed at our web site (http://mic.greenresource.cn/intex-b2006).
32
Di Lorenzo, Giuseppe, Emma Frosina, Luigi De Petrillo, Davide Lauria, Adolfo Senatore, Francesco Curreri, Guido Saccone, Marcello Kivel Mazuy e Ciro Pascarella. "Design and Development of Hybrid-Electric Propulsion Model for Aeronautics". MATEC Web of Conferences 304 (2019): 03012. http://dx.doi.org/10.1051/matecconf/201930403012.
Abstract (sommario):
Nowadays, worldwide environmental issue, associated to reduction of pollutant and greenhouse emissions are gaining considerable attention. Aviation sector contribution to the whole CO2 released accounts to around 2%, but it is expected to grow in the next future due to increase of demand. Probably, combustion engine design and fuel efficiency have already reached their optimum technology level and only a breakthrough as hybrid-electric propulsion could be able to satisfy the new international more demanding requirements. However, an improvement of the technology readiness level of hybrid-electric propulsion is strongly necessary and many operational and safety challenges should be addressed. In the work here reported, a hybrid-electric model was designed and developed for general aviation aircrafts, by means of the Mathworks® Matlab – Simulink 1D/0D simulation environment. Both thermal and electric energy storage units, transmission systems and power management devices were considered and the overall performances were evaluated during cruise phase and a conventional training mission, characterized by several run(lap) “touch-and-go”. Furthermore, an innovative mathematical methodology was implemented for battery pack discharge profile interpolation. Finally, reliability and accuracy of the new proposed model were evaluated through comparison with the commercial code Simcenter AMESim® software and an average bias only equal to 5% was achieved.
33
Laurin, Frédéric, Alexander Beutl, Qixiang Jiang e Helmut Kühnelt. "Concepts for integrating electrical energy storage into CFRP laminate structures for aeronautic applications". Journal of Physics: Conference Series 2526, n. 1 (1 giugno 2023): 012062. http://dx.doi.org/10.1088/1742-6596/2526/1/012062.
Abstract (sommario):
Abstract The CleanSky2 THT project SOLIFLY is developing further structural batteries for aeronautical applications. This paper presents the concepts of structural integration and the methodology to evaluate the impact of structural battery integration on the mechanical properties of CFRP solid laminates considering the size and shape of the structural battery insert as well as its location through the laminate thickness. A fully parameterised, computationally efficient numerical strategy for finite element simulation has been implemented to evaluate the mechanical properties and, for the first time, the onset of matrix damage as the cell geometry and integration location are varied. The first mechanical characterisation data of SB cell components and cell prototypes were obtained thanks to multi-instrumented tensile tests using digital image correlation and acoustic emission. An initial assessment of the advantages and trade-offs of the SB integration concepts with respect to functionally separated components is discussed.
34
Centracchio, Francesco, Monica Rossetti e Umberto Iemma. "Approach to the Weight Estimation in the Conceptual Design of Hybrid-Electric-Powered Unconventional Regional Aircraft". Journal of Advanced Transportation 2018 (17 ottobre 2018): 1–15. http://dx.doi.org/10.1155/2018/6320197.
Abstract (sommario):
The present work deals with the development of an innovative approach to the weight estimation in the conceptual design of a Hybrid-Electric-Powered (HEP) Blended Wing Body (BWB) commercial aircraft. In the last few decades, the improvement of the environmental impact of civil aviation has been the major concern of the aeronautical engineering community, in order to guarantee the sustainable development of the system in presence of a constantly growing market demand. The sustained effort in the improvement of the overall efficiency of conventional aircraft has produced a new generation of vehicles with an extremely low level of emissions and noise, capable of covering the community requirements in the short term. Unfortunately, the remarkable improvements achieved represent the asymptotic limit reachable through the incremental enhancement of existing concepts. Any further improvement to conform to the strict future environmental target will be possible only through the introduction of breakthrough concepts. The aeronautical engineering community is thus concentrating the research on unconventional airframes, innovative low-noise technologies, and alternative propulsion systems. The BWB is one of the most promising layouts in terms of noise emissions and chemical pollution. The further reduction of fuel consumption that can be achieved with gas/electric hybridisation of the power-plant is herein addressed in the context of multidisciplinary analyses. In particular, the payload and range limits are assessed in relation to the technological development of the electric components of the propulsion system. The present work explores the potentialities of an energy-based approach for the initial sizing of a HEP unconventional aircraft in the early conceptual phase of the design. A detailed parametric analysis has been carried out to emphasise how payload, range, and degree of hybridisation are strictly connected in terms of feasible mission requirements and related to the reasonable expectations of development of electric components suitable for aeronautical applications.
35
Abrams, Michael, e Yasushi Yamaguchi. "Twenty Years of ASTER Contributions to Lithologic Mapping and Mineral Exploration". Remote Sensing 11, n. 11 (11 giugno 2019): 1394. http://dx.doi.org/10.3390/rs11111394.
Abstract (sommario):
The Advanced Spaceborne Thermal Emission and Reflection Radiometer is one of five instruments operating on the National Aeronautics and Space Administration (NASA) Terra platform. Launched in 1999, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) has been acquiring optical data for 20 years. ASTER is a joint project between Japan’s Ministry of Economy, Trade and Industry; and U.S. National Aeronautics and Space Administration. Numerous reports of geologic mapping and mineral exploration applications of ASTER data attest to the unique capabilities of the instrument. Until 2000, Landsat was the instrument of choice to provide surface composition information. Its scanners had two broadband short wave infrared (SWIR) bands and a single thermal infrared band. A single SWIR band amalgamated all diagnostic absorption features in the 2–2.5 micron wavelength region into a single band, providing no information on mineral composition. Clays, carbonates, and sulfates could only be detected as a single group. The single thermal infrared (TIR) band provided no information on silicate composition (felsic vs. mafic igneous rocks; quartz content of sedimentary rocks). Since 2000, all of these mineralogical distinctions, and more, could be accomplished due to ASTER’s unique, high spatial resolution multispectral bands: six in the SWIR and five in the TIR. The data have sufficient information to provide good results using the simplest techniques, like band ratios, or more sophisticated analyses, like machine learning. A robust archive of images facilitated use of the data for global exploration and mapping.
36
Charron, Graig S., e Daniel J. Cantliffe. "243 VOLATILE EMISSIONS FROM LETTUCE GROWN UNDER DIFFERENT TEMPERATURES, LIGHT INTENSITIES, AND PHOTOPERIODS". HortScience 29, n. 5 (maggio 1994): 464d—464. http://dx.doi.org/10.21273/hortsci.29.5.464d.
Abstract (sommario):
The National Aeronautics and Space Administration (NASA) is developing a Controlled Ecological Life Support System (CELSS) for long-term space exploration in which plants would be one major component. Volatile emissions from these plants may disrupt the proper functioning of CELSS. This research investigated how environmental factors alter the volatile emissions from hydroponically-grown `Waldmann's Green' leaf lettuce. A growth chamber was modified to allow the injection of purified air into a glass enclosure positioned over individual lettuce plants. Air samples from the enclosure were analyzed by gas chromatography-mass spectrometry (GC-MS). The lipoxygenase pathway products (Z)-3-hexenal, (Z)-3-hexenol, and (Z)3-hexenyl acetate were emitted following the end of the light period. Mechanical damage also stimulated the release of these same compounds. The design of toxin management systems in CELSS may need to incorporate these findings. Additionally, lipoxygenase pathway products have been previously demonstrated to influence insect behavior and pathogen growth, and may indicate future directions for plant breeding.
37
Sparks, W. B., M. McGrath, K. Hand, H. C. Ford, P. Geissler, J. H. Hough, E. L. Turner, C. F. Chyba, R. Carlson e M. Turnbull. "Hubble Space Telescope observations of Europa in and out of eclipse". International Journal of Astrobiology 9, n. 4 (24 agosto 2010): 265–71. http://dx.doi.org/10.1017/s1473550410000285.
Abstract (sommario):
AbstractEuropa is a prime target for astrobiology and has been prioritized as the next target for a National Aeronautics and Space Administration flagship mission. It is important, therefore, that we advance our understanding of Europa, its ocean and physical environment as much as possible. Here, we describe observations of Europa obtained during its orbital eclipse by Jupiter using the Hubble Space Telescope. We obtained Advanced Camera for Surveys Solar Blind Channel far ultraviolet low-resolution spectra that show oxygen line emission both in and out of eclipse. We also used the Wide-Field and Planetary Camera-2 and searched for broad-band optical emission from fluorescence of the surface material, arising from the very high level of incident energetic particle radiation on ices and potentially organic substances. The high-energy particle radiation at the surface of Europa is extremely intense and is responsible for the production of a tenuous oxygen atmosphere and associated FUV line emission. Approximately 50% of the oxygen emission lasts at least a few hours into the eclipse. We discuss the detection limits of the optical emission, which allow us to estimate the fraction of incident energy reradiated at optical wavelengths, through electron-excited emission, Cherenkov radiation in the ice and fluorescent processes.
38
da Silva, Francisco Ferreira, João F. P. Fernandes e Paulo Jose da Costa Branco. "Barriers and Challenges Going from Conventional to Cryogenic Superconducting Propulsion for Hybrid and All-Electric Aircrafts". Energies 14, n. 21 (20 ottobre 2021): 6861. http://dx.doi.org/10.3390/en14216861.
Abstract (sommario):
The development of electric aircraft is becoming an important technology for achieving the goals set by the European Commission for the reduction of gases emissions by 2050 in the aeronautical transportation system. However, there is a technology gap between the current values of specific power in commercial electric machines and those required for aeronautical applications. Therefore, the search for alternative materials and non-conventional designs is mandatory. One emergent solution is using superconducting machines and systems to overcome the current limits of conventional electrical machines. This work reviews the new hybrid and all-electric aircraft tendencies, complementing it with recent research on the design and development of high specific power superconducting machines. This includes the main topologies for hybrid and all-electric aircraft, with an overview of the ongoing worldwide projects of these aircraft types, systematizing the main characteristics of their propulsion systems. It also includes the research on superconducting machines to achieve high specific power and consider the impact on the redesign of aircraft systems, the electrical, cooling, and fuel source systems.
39
Harrigan, D. L., H. E. Fuelberg, I. J. Simpson, D. R. Blake, G. R. Carmichael e G. S. Diskin. "Anthropogenic emissions during Arctas-A: mean transport characteristics and regional case studies". Atmospheric Chemistry and Physics 11, n. 16 (25 agosto 2011): 8677–701. http://dx.doi.org/10.5194/acp-11-8677-2011.
Abstract (sommario):
Abstract. The National Aeronautics and Space Administration (NASA) conducted the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission during 2008 as a part of the International Polar Year (IPY). The purpose of ARCTAS was to study the factors responsible for changes in the Arctic's atmospheric composition and climate. A major emphasis was to investigate Arctic haze, which is most pronounced during winter and early spring. This study focuses on the spring phase of ARCTAS (ARCTAS-A) that was based in Alaska during April 2008. Although anthropogenic emissions historically have been associated with Arctic haze, biomass burning emissions dominated the ARCTAS-A period and have been the focus of many ARCTAS related studies. This study determines mean transport characteristics of anthropogenic emissions during ARCTAS-A. Trajectories are initiated each day from three significant regions of anthropogenic emissions (Asia, North America, and Europe). The fifteen day forward trajectories are calculated using data from the Weather Research and Forecasting (WRF) model at 45 km horizontal resolution. The trajectory calculations indicate: origins of emissions that reach the Arctic (defined as north of 70° N) within fifteen days, pathways of these emissions, Arctic entry locations, and altitudes at which the trajectories enter the Arctic. Three cases during the ARCTAS-A period (one for each of the regions above) are examined using backward trajectories and chemical fingerprinting based on in situ data sampled from the NASA DC-8. The fingerprinting utilizes volatile organic compounds that represent pure anthropogenic tracers, Asian anthropogenic pollution, incomplete combustion, and natural gas emissions. We determine flight legs containing anthropogenic emissions and the pathways travelled by these emissions. Results show that the DC-8 sampled anthropogenic emissions from Asia, North America, and Europe during the spring phase of ARCTAS. The pathways travelled by these emissions agree with our derived transport characteristics and previous studies of Arctic transport. Meteorological analysis and trajectory calculations indicate that middle latitude cyclones and their associated warm conveyor belts play an important role in lofting the surface based emissions to their sampling altitude in all three cases.
40
Harrigan, D. L., H. E. Fuelberg, I. J. Simpson, D. R. Blake, G. R. Carmichael e G. S. Diskin. "Transport of anthropogenic emissions during ARCTAS-A: a climatology and regional case studies". Atmospheric Chemistry and Physics Discussions 11, n. 2 (15 febbraio 2011): 5435–91. http://dx.doi.org/10.5194/acpd-11-5435-2011.
Abstract (sommario):
Abstract. The National Aeronautics and Space Administration (NASA) conducted the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission during 2008 as a part of the International Polar Year (IPY). The purpose of ARCTAS was to study the factors responsible for changes in the Arctic's atmospheric composition and climate. A major emphasis was to investigate Arctic haze, which is most pronounced during winter and early spring. This study focuses on the spring phase of ARCTAS (ARCTAS-A) that was based in Alaska during April 2008. Although anthropogenic emissions historically have been associated with Arctic haze, biomass burning dominated the ARCTAS-A period and has been the focus of many ARCTAS related studies. This study determines the common pathways for anthropogenic emissions during ARCTAS-A. Trajectories (air parcels) are released each day from three historically significant regions of anthropogenic emissions (Asia, North America, and Europe). These fifteen day forward trajectories are calculated using data from the Weather Research and Forecasting (WRF) model at 45 km horizontal resolution. The trajectories then are examined to determine: origins of emissions that reach the Arctic (defined as north of 70° N) within fifteen days, pathways of the emissions reaching the Arctic, Arctic entry locations, and altitudes at which the trajectories enter the Arctic. These results serve as regional "climatologies" for the ARCTAS-A period. Three cases during the ARCTAS-A period (one for each of the regions above) are examined using backward trajectories and chemical fingerprinting based on in situ data sampled from the NASA DC-8. The fingerprinting utilizes volatile organic compounds that represent pure anthropogenic tracers, Asian anthropogenic pollution, incomplete combustion, and natural gas emissions. We determine flight legs containing anthropogenic emissions and the pathways travelled by these emissions. Results show that the DC-8 sampled anthropogenic emissions from Asia, North America, and Europe during the spring phase of ARCTAS. The pathways travelled by these emissions agree with our derived "climatologies" and previous studies of Arctic transport. Meteorological analysis and trajectory calculations indicate that middle latitude cyclones and their associated warm conveyor belts play an important role in lofting the surface based emissions to their sampling altitude in all three cases.
41
Kolka, Randall K., Brian R. Sturtevant, Jessica R. Miesel, Aditya Singh, Peter T. Wolter, Shawn Fraver, Thomas M. DeSutter e Phil A. Townsend. "Emissions of forest floor and mineral soil carbon, nitrogen and mercury pools and relationships with fire severity for the Pagami Creek Fire in the Boreal Forest of northern Minnesota". International Journal of Wildland Fire 26, n. 4 (2017): 296. http://dx.doi.org/10.1071/wf16128.
Abstract (sommario):
Forest fires cause large emissions of C (carbon), N (nitrogen) and Hg (mercury) to the atmosphere and thus have important implications for global warming (e.g. via CO2 and N2O emissions), anthropogenic fertilisation of natural ecosystems (e.g. via N deposition), and bioaccumulation of harmful metals in aquatic and terrestrial systems (e.g. via Hg deposition). Research indicates that fires are becoming more severe over much of North America, thus increasing element emissions during fire. However, there has been little research relating forest floor and mineral soil losses of C, N and Hg to on-the-ground indices of fire severity that enable scaling up those losses for larger-scale accounting of fire-level emissions. We investigated the relationships between forest floor and mineral soil elemental pools across a range of soil-level fire severities following the 2011 Pagami Creek wildfire in northern Minnesota, USA. We were able to statistically differentiate losses of forest floor C, N and Hg among a five-class soil-level fire severity classification system. Regression relationships using soil fire severity class were able to predict remaining forest floor C, N and Hg pools with 82–96% confidence. We correlated National Aeronautics and Space Administration Airborne Visible and Infrared Imaging Spectrometer-Classic imagery to ground-based plot-scale estimates of soil fire severity to upscale emissions of C, N and Hg to the fire level. We estimate that 468 000 Mg C, 11 000 Mg of N and over 122 g of Hg were emitted from the forest floor during the burning of the 28 310 ha upland area of the Pagami Creek fire.
42
Lykotrafiti, Antigoni. "EU Innovation Policy: Lessons Learned from the Inclusion of Aviation in the EU Emissions Trading Scheme". Legal Issues of Economic Integration 40, Issue 4 (1 novembre 2013): 339–61. http://dx.doi.org/10.54648/leie2013018.
Abstract (sommario):
The article looks at the inclusion of aviation in the European Union (EU) emissions trading scheme from the perspective of innovation. It argues that the initiative of the European Union to subject aviation to the scheme has functioned as a catalyst for innovation in the sector. Innovation has particularly manifested itself in the areas of air traffic management, aeronautics and biofuels. The article examines the EU mechanisms activated to foster innovation to draw conclusions on the existence and nature of an EU innovation policy. It approaches innovation as a means to achieve the objectives of the various EU policies rather than as an end in itself. Drawing upon the example of aviation it concludes that, although it does not appear that the EU has developed an autonomous system of horizontal rules on innovation, it does have plenty of instruments, which, if well-orchestrated, could lead to an innovation concert.
43
Ramasso, Emmanuel, Benoît Verdin e Gaël Chevallier. "Monitoring a Bolted Vibrating Structure Using Multiple Acoustic Emission Sensors: A Benchmark". Data 7, n. 3 (2 marzo 2022): 31. http://dx.doi.org/10.3390/data7030031.
Abstract (sommario):
The dataset presented in this work, called ORION-AE, is made of raw AE data streams collected by three different AE sensors and a laser vibrometer during five campaigns of measurements by varying the tightening conditions of two bolted plates submitted to harmonic vibration tests. With seven different operating conditions, this dataset was designed to challenge supervised and unsupervised machine/deep learning as well as signal processing methods which are developed for material characterization or structural health monitoring (SHM). One motivation of this work was to create a common benchmark for comparing data-driven methods dedicated to AE data interpretation. The dataset is made of time series collected during an experiment designed to reproduce the loosening phenomenon observed in aeronautics, automotive, or civil engineering structures where parts are assembled together by means of bolted joints. Monitoring loosening in jointed structures during operation remains challenging because contact and friction in bolted joints induce a nonlinear stochastic behavior.
44
Blanco, David, Eva María Rubio, José Manuel Sáenz de Pipaón e Marta María Marín. "Thicknesses/Roughness Relationship in Mg-Al-Mg and Mg-Ti-Mg Hybrid Component Plates for Drilled Aeronautical Lightweight Parts". Applied Sciences 10, n. 22 (19 novembre 2020): 8208. http://dx.doi.org/10.3390/app10228208.
Abstract (sommario):
Multimaterial hybrid compounds formed from lightweight structural materials have been acquiring great importance in recent years in the aeronautical and automotive sectors, where they are replacing traditional materials to reduce the mass of vehicles; this will enable either an increase in the action ratio or a reduction in the fuel consumption of vehicles and, in short, will lead to savings in transport costs and a reduction in polluting emissions. Besides, the implementation of production and consumption models based on the circular economy is becoming more and more important, where the repair and, for this purpose, the use of recyclable materials, is crucial. In this context, the analysis of a repair process is carried out by re-drilling Mg-Al-Mg multimaterial components using experimental design (DoE) based on Taguchi methodology, an analysis of variance (ANOVA) and descriptive statistics. The study concludes which are the significant factors and interactions of the process, comparing the results with previous similar studies, and establishing bases to determine the optimum thicknesses of hybrid magnesium-based component plates of drilled parts in the aeronautical industry, guaranteeing surface roughness requirements in repair and maintenance operations throughout their lifetime.
45
Green, J. E. "Greener by Design — the technology challenge". Aeronautical Journal 106, n. 1056 (febbraio 2002): 57–113. http://dx.doi.org/10.1017/s0001924000095993.
Abstract (sommario):
The effects of aviation on the environment are becoming increasingly important. The world's airlines already have thousands of aircraft serving the passenger and freight markets and the market demand is still increasing. Unless steps are taken to address the problems created by aircraft noise and emissions, the future progress of the air transport industry will be inhibited.The seriousness of the topic and the factual nature of the Technology Sub Group report are the reasons why this special issue of The Aeronautical Journal is being devoted to “Greener by Design”. Although the report has been carefully read by a number of people outside the Sub Group, it has not been refereed in the normal way (though a number of minor numerical changes have been made to the tables and text of the original report, partly to correct errors and partly for internal consistency). The reports from the other two Sub Groups, covering operations and market-based options, together with the Summary for Policymakers of the Technology Sub Group, will be issued shortly in a single volume but will not necessarily be published in The Aeronautical Journal.
46
Fąfara, Jean-Marc. "Overview of low emission combustors of aircraft turbine drive units". Combustion Engines 183, n. 4 (15 dicembre 2020): 45–49. http://dx.doi.org/10.19206/ce-2020-407.
Abstract (sommario):
It is important to notice that aircraft turbine drive units are commonly used in the modern aviation. The piston engines are often reserved for small and/or sportive aircraft. The turbine drive units are also combustion engine. This paper presents the most popular combustors used in the aeronautical turbine engines. Firstly there are listed the requirements that a combustor has to achieve. Then are presented the combustor designs that permit to achieve the firstly presented requirements. In this work are presented the LPP, TAPS, RQL, graduated combustion zone, VGC, exhaust recirculation system combustors. For each combustor design is enlighten its principle of work, described the etymology of the given name to this design and shown a scheme. The work is closed by a briefly conclusion about the described combustor.
47
Pan, Li, Partha S. Bhattacharjee, Li Zhang, Raffaele Montuoro, Barry Baker, Jeff McQueen, Georg A. Grell et al. "Analysis of the GEFS-Aerosols annual budget to better understand aerosol predictions simulated in the model". Geoscientific Model Development 17, n. 1 (16 gennaio 2024): 431–47. http://dx.doi.org/10.5194/gmd-17-431-2024.
Abstract (sommario):
Abstract. In September 2020, a global aerosol forecasting model was implemented as an ensemble member of the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) Global Ensemble Forecasting System (GEFS) v12.0.1 (hereafter referred to as “GEFS-Aerosols”). In this study, GEFS-Aerosols simulation results from 1 September 2019 to 30 September 2020 were evaluated using an aerosol budget analysis. These results were compared with results from other global models as well as reanalysis data. From this analysis, the global average lifetimes of black carbon (BC), organic carbon (OC), dust, sea salt, and sulfate are 4.06, 4.29, 4.59, 0.34, and 3.3 d, respectively, with the annual average loads of 0.14, 1.29, 4.52, 6.80, and 0.51 Tg. Compared with the National Aeronautics and Space Administration (NASA) Goddard Earth Observing System–Goddard Chemistry Aerosol and Radiation Transport (GEOS4-GOCART) model, the aerosols in GEFS-Aerosols have a relatively short lifetime because of the faster removal processes in GEFS-Aerosols. Meanwhile, in GEFS-Aerosols, aerosol emissions are the determining factor for the mass and composition of aerosols in the atmosphere. The size (bin) distribution of aerosol emissions is as important as its total emissions, especially in simulations of dust and sea salt. Moreover, most importantly, the strong monthly and interannual variations in natural sources of aerosols in GEFS-Aerosols suggest that improving the accuracy of the prognostic concentrations of aerosols is important for applying aerosol feedback to weather and climate predictions.
48
Blanco, D., E. M. Rubio, M. M. Marín e A. M. Camacho. "Sustainable and advanced manufacturing processes of light structural materials of the transport sector". IOP Conference Series: Materials Science and Engineering 1193, n. 1 (1 ottobre 2021): 012126. http://dx.doi.org/10.1088/1757-899x/1193/1/012126.
Abstract (sommario):
Abstract 30% of emissions in the European Union (EU) originate from transport, and there are commitments by all sectors involved, road transport, civil aviation and maritime for a progressive reduction. The mass of the vehicles has a significant influence on their consumption and emissions, so there is a need to replace traditional heavy materials with light structural materials or combinations of them, and to optimise their manufacturing processes. This work reviews the scientific literature published during the period 2015-19. Aiming to select the most relevant articles minimizing the bias, a search strategy is defined, applied in the Web of Science database, and the selection limited to publications in Open Access, English, Q1-Q2 journals or prestigious conference proceedings, from 01/01/2015 to 01/01/2020. The final objective of the work is to provide a global perspective of the latest trends in studies on light structural materials with application in the aeronautical and/or automotive fields, of studies oriented towards sustainability, and with a special interest in those that apply advanced manufacturing and/or machining processes.
49
Hellweg, Robert, e Gregg G. Fleming. "Unmanned air systems (UAS/UAV) (drone) and aerial mobility: summaries of the 2018 and 2020 TQA workshops". INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, n. 1 (1 agosto 2021): 4945–54. http://dx.doi.org/10.3397/in-2021-2899.
Abstract (sommario):
Unmanned air system (UAS/UAV) noise and urban mobility noise were the subject of two National Academy of Engineering (NAE) hosted workshops under the auspices of the Technology of Quieter America (TQA) program. Both workshops were organized by the INCE Foundation in cooperation with the U.S. National Aeronautics and Space Administration (NASA) and the U.S. Federal Aviation Administration (FAA). The first workshop "UAS and UAV (Drone): Noise Emissions and Noise Control Engineering Technology" was held in Washington, DC in December, 2018. manufacturers, users, U.S. government agencies, universities, consultants and professional societies. The second was an e-workshop "Aerial Mobility: Noise Issues and Technology" in December, 2020. Participants at each workshop included representatives from manufacturers (US and international), users, U.S. government agencies, academia, consultants, professional societies, and law firms. Topics included: modelling, testing, psychoacoustics, community impact, noise reduction strategies, measurement techniques, and uses of both UAS/UAVs and aerial mobility.
50
Choubey, Abhishek, Prashant Baredar e Neha Choubey. "Power Optimization of NACA 0018 Airfoil Blade of Horizontal Axis Wind Turbine by CFD Analysis". International Journal of Energy Optimization and Engineering 9, n. 1 (gennaio 2020): 122–39. http://dx.doi.org/10.4018/ijeoe.2020010104.
Abstract (sommario):
The country or region where energy production is based on imported coal or oil will become more self-sufficient by using alternatives such as wind power. Electricity produced by the wind produces no CO2 emissions and therefore does not contribute to the greenhouse effect. Wind energy is relatively labour intensive and thus creates many jobs. Wind energy is the major alternative of conventional energy resources. A wind turbine transforms the kinetic energy in the wind to mechanical energy in a shaft and finally into electrical energy in a generator. The turbine blade is the most important component of any wind turbine. In this article is considered the single airfoil National Advisory Committee for Aeronautics (NACA) 0018 and a computational fluid dynamics (CFD) analysis is done at different blade angles 0º, 10º, 15º, and 30º with a wind velocity of 4 m/s. The analysis results show that a blade angle of 10º gives the best possible power and pressure and velocity distributions are plotted for every case.