Aircraft Technology Research Articles

The Grand Designers: The Evolution of the Airplane in the 20th Century by John D. Anderson Jr.

Reviewed by: The Grand Designers: The Evolution of the Airplane in the 20th Century by John D. Anderson Jr. Marc J. Alsina (bio) The Grand Designers: The Evolution of the Airplane in the 20th Century By John D. Anderson Jr. New York: Cambridge University Press, 2018. Even the most cursory comparison of a Wright Flyer and a modern airliner leaves no doubt about the dizzying rate of change in aircraft technology throughout the twentieth century. In his latest book, National Air & Space Museum Curator of Aerodynamics John D. Anderson Jr. investigates what he describes as the “intellectual methodology” of conceptual aircraft design that drove the swift improvement of aviation technology. Anderson follows the careers of several “grand designers”—the Wright Brothers, Frank Barnwell, Arthur Raymond, R. J. Mitchell, Edgar Schmued, and Kelly Johnson—revealing the design processes these men used to transform their ideas into highly successful aircraft. [End Page 976] As Anderson explains, conceptual design is the first stage in creating a new airplane. Generally, the designer starts with a blank sheet of paper, then establishes the basic layout that will ideally meet the potential users’ performance requirements. Alongside their analysis of experimental data, aircraft designers marshal their experience, intuition, and aesthetic preferences to mold their creations. Anderson argues that despite differing personalities and education, all of his “grand designers” used the same basic methodology to establish and refine their conceptual designs. He begins with the nineteenth-century rudimentary flying machines, whose creators largely lacked a cohesive design methodology. In chapter two, Anderson reveals how the Wright Brothers were the first to create a “rational methodology” for aircraft design. In addition to understanding the airplane as a system, the brothers refined their design using mathematical parameters such as weight, lift coefficients, and velocity. These “design points” focused their design and experimentation process, eventually garnering them success where so many others failed. Yet the next designer, Frank Barnwell, is at the heart of The Grand Designers. Anderson argues that Barnwell, a fixture of the British aircraft industry until his death in 1928, set the “gold standard” for conceptual design. In his 1916 book Aeroplane Design, Barnwell described his process as starting with a precise outline of requirements before making a weight estimate. The requirements and projected weight then determined the desired performance parameters for the aircraft (such as the lift-to-drag ratio). Only then did the designer sketch a basic layout. Barnwell then reevaluated the estimated performance of the aircraft and made adjustments. Anderson argues that Barnwell’s method became commonplace in the aircraft design community. The other case studies reinforce the centrality of Barnwell’s methodology. In chapter four, Anderson follows Arthur Raymond and the creation of the DC-3 during the first “design revolution” in aviation in the late 1920s and early 1930s. The author emphasizes that Raymond used the same intellectual methodology of design, despite new advancements in streamlining, engines, and construction. This line of argument, however, is stretched in the subsequent chapters discussing R. J. Mitchell’s work on the Spitfire, Edgar Schmued on the P-51 Mustang, and Kelly Johnson with the “Skunk Works.” The book would have benefited from further analysis of these radical new technologies and the eccentricities of these designers. While Anderson focuses on the similarities of their methods, he also draws interesting distinctions in their uses of wind tunnel data, aerodynamic theory, and aesthetic taste for shaping their design. These details dispel any notion that educational background or familiarity with scientific theory were the sole determinants of success in the first half of the twentieth century. The Grand Designers is intended for both nontechnical and technical audiences and indeed succeeds in being accessible for newcomers to aviation [End Page 977] history and compelling for technical readers. Anderson excels when explaining complex processes of design, aerodynamic theory, and experimental testing. The many images accompanying the text bring extra clarity to what might have been an abstruse subject. Anderson’s secondary arguments about education and the relevance of scientific experimentation and theory to these grand designers’ processes deserve more emphasis. Furthermore, extensive footnoting would have helped to separate technical information from the overall narrative of each chapter. The Grand Designers is an...

High-precision relative posture real-time measurement technology for a certain aircraft

High-precision relative posture real-time measurement technology for a certain aircraft

Progress and challenges of next generation green supersonic civil aircraft

After decades of development, the design technology of high subsonic civil aircraft has been quite mature in terms of safety, economy, comfort and environmental friendly. But for trans-continental and trans-oceanic travel, the flight time up to more than ten hours is still too long, and it becomes the bottleneck in the comfort and rapidity of long-distance travel experience. In contrast, the design technology for supersonic civil aircraft (at least twice speed as fast as that of subsonic one) has been greatly improved, which can greatly shorten the duration in the air. Concorde, the 1st generation supersonic civil aircraft, putting into commercial operation in January 1976, was one of the greatest technological innovations of mankind at that time. But its weaknesses of high fuel consumption, unbearable noise level and pollution problem have seriously weakened the market competitiveness and finally led to the end of commercial operations. There were setbacks, but the technology development never stopped. Compared with that in the 1960s and 1970s, the theory level and practical level of aviation technology have been greatly improved with the help of achievements in fundamental science and technology area. The various technical bottlenecks that hindered the development of supersonic civil aircraft have been continuously alleviated or eliminated, and the technical conditions for the development of green supersonic civil aircraft have become increasingly mature. Since the 1990s, supersonic civil aircrafts have attracted great attention again and gradually become one of the research hotspots. The current concerns about the next generation supersonic civil aircraft cover a wide range, not only the normal demand of low resistance and low fuel consumption, but also some environmentally friendly features. The strength of sonic boom should be reduced to an acceptable level, and continue meet both the increasing noise standards around the airport community and low engine emission requirements. In China, on one hand, we started late but have made great progress in the research of supersonic civil aircraft, such as the fields of aerodynamic configuration, sonic boom prediction and its suppression technology, and supersonic drag reduction technology. And a wide range of independent tools for supersonic civil aircraft concept design, near-field/far-field sonic boom prediction, and multi- design-point/multi-objective aerodynamic configuration optimization design were developed. On the other hand, the supersonic commercial engine technology is still in a blank state, which is a key issue that restricts the development of China’s green supersonic civil aircraft. Compared with the current development level of supersonic civil aircraft design technology worldwide, there are still significant challenges to achieve supersonic flight with economically affordability and green feathers. But it is foreseeable that the next generation green supersonic civil aircraft could be expected before the end of the third decade of this century.

Исследование структуры и свойств образцов из жаропрочного сплава Inconel 738, полученных методом селективного лазерного сплавления (SLM)

Currently, the selective laser melting technique (SLM) with the use of powder metallic materials is a promising area in the aircraft and engine technology. Due to this technique, it is possible to produce parts with any complexity configuration at fewer expenses for tooling and mechanical processing and the prototyping of goods becomes simpler as well. The issue of application of powder materials of heat-resisting alloys in the additive production is particularly topical, which is due to the problems caused by their complex chemical composition, insufficient thermal conductivity, and shrinkage tendency. The paper studies the influence of laser output power on the microstructure and properties of specimens of Inconel 738 heat-resisting nickel alloy produced with the help of a commercial 3-D printer using the SLM printing technology. Moreover, the authors considered the way of improvement of the specimens’ mechanical properties through the improvement of microstructure after SLM and further heat treatment. The authors carried out the metallographic and electron microscopic study of the initial material and the specimens grown using the SLM technology at the laser output power of 75, 100, 125, and 325 W; analyzed the microstructure evolution in the result of heating caused by the growth of supply energy. Further heat treatment made it possible to study the influence of step quenching on the microstructure and mechanical properties of specimens. Further heat treatment made it possible to study the influence of step quenching on the microstructure and mechanical properties of specimens. The authors determined the optimum technological parameters of laser emission to produce parts from Inconel 738 heat-resisting alloy using the SLM technique and produced parts with the minimum quantity of the defects. The study identified that heat treatment, including step quenching, improves the mechanical properties - ultimate resistance, yield limit, and percent elongation - through the “healing” and the defects’ size reduction.

11,000 miles!

11,000 miles! Victoria Avery Lainie Anderson . Long Flight Home. South Australia: Wakefield Press. 2019. 357 pp. n.p. ISBN 978-1-74305-663-9 The story is based on the true story of the 1919 England-to-Australia contest to celebrate who could be the first to make the long-distance flight. The flight was significant in finding use for aircraft technology for activities outside of war efforts, as well as pushing the limits of aircraft design for the time. The main character, Wally, is one of the crew who makes this journey. Much of Wally's story seems to occur because of happenstance. At the outset of the story, he finds the love of his life, Helena, after witnessing the egging of her house during a walk. He meets Helena and her family after offering to help clean up the mess. After Wally falls in love with Helena and impulsively asks her to marry him, his plans are altered after being persuaded to enlist in the war efforts and sent abroad. His acumen with mechanics translates well to working on the latest technology of aircraft during the war, a skill needed after the war as well. Much as when he is persuaded to enlist in the war, he becomes caught up in his friends' enthusiasm and chooses to enter a contest to fly with them from England to Australia. Through the contest, the book explores themes of cooperation and perseverance. The author could have chosen to write from the perspective of the heroic pilot of the Vickers Vimy aircraft, Ross Smith, or even his brother, Keith Smith, the navigator. Instead, she cleverly chose to tell the story through the eyes of one of the mechanics. Telling the story through the point of view of a mechanic highlights how many people participate in the making of heroic ventures—people who remain largely out of the spotlight. Without Benny and Wally, the plane would not have completed the eleven-thousand-mile journey. Furthermore, without the help of those who made sure the fuel supply was available at the checkpoints or helped the Vickers Vimy out of tight spots, the journey would not have been completed at all. For example, when the necessary runway was muddied to the point of being impossible to use, the locals came out to offer their assistance. "As the sun rose they arrived in their hundreds," "generously offering sheets [End Page 141] of bamboo matting they'd stripped from the walls of their own homes" (283). The journey was perilous at that time, and only one other crew made it the complete distance. By arranging the story through the perspective of Wally, we are taken to the back of the plane, behind the scenes, to see the structures that need to be in place to support such heroes as Ross Smith. Although the back of the book highlights the sustaining relationship between Helena and Wally despite distance and time, the relationships built between Wally and his war friends feel more fully developed. Helena makes a brief appearance at the outset of the novel, and we see her again through her letters; but she sometimes feels more symbol, a modern Penelope, than fully realized figure. Even when she breaks off the engagement with Wally, she remains a part of the symbol of home for him, tied up with his memories of the Australian landscape and a hope for a peaceful future. His respect and appreciation for Ross Smith, whom he meets during his time in North Africa, is as powerful as his connection to Helena. Nevertheless, it is partly because of his devotion to this superior officer, Ross Smith, that he decides to postpone his journey home. The story is organized into three parts: Wally's time during the First World War; his time setting up for the contest; and the journey from England to Australia. Although there is tension in the second section, scenes detailing Wally and his friends as they struggle to enter the contest and find a plane, the section is a slow point in an otherwise actionpacked book. Anderson shines best when her characters fight against the odds of environmental forces. Struggling against...

Study on LabVIEW-based Aviation BLDCM Control System

with the increasing market demand and rapid development of aircraft technology, more electric concept has become an important trend for the future development of aircraft. Therefore, motors are widely applied in the aviation field increasingly. This paper mainly introduces the hardware environment and LabVIEW implementation process in the development of aviation high speed and high voltage BLDCM control system based on NI hardware and software platform. The test shows the control system is able to realize effective control over aviation BLDCM. This system is highly flexible and can lay a foundation for the algorithms used in subsequent related research efforts.

A theory of the evolution of technology: Technological parasitism and the implications for innovation magement

How do technologies develop? This study proposes the theory of technological parasitism that is based on the idea that parasite-host relationships between technologies and technologies with a high number of technological parasites have an accelerated evolution driven by long-run mutualistic symbioses, providing the basis for extensive macroevolution and adaptive behavior of systems of interactive technologies in markets. This theory may be useful for bringing a new perspective to explain and generalize the evolution of technology directed to sustain competitive advantage of firms and nations. In particular, technological parasitism explains the relationship of mutualistic symbiosis between a host (or master) technology and inter-related technologies to satisfy needs and/or to solve consequential problems of socioeconomic subjects over time. To explore the potential of adopting a theory of technological parasitism and to predict which technologies are likeliest to evolve rapidly, this study implements a theoretical test based on a computational agent-based model developed from these concepts and a empirical test based on historical data on the evolution of four example technologies (aircraft, tractor, locomotive and bicycle technology). Computational and empirical evidence are broadly consistent with the theoretical expectation that host (or master) technologies with many associated parasitic technologies advance rapidly, whereas master technologies with fewer parasitic technologies improve slowly. The proposed theory has a demonstrated capacity to explain relationships between technologies in complex systems that clarify the driving forces of the evolution of technology in markets. The finding of this study could aid management of firms and innovation strategy of nations to implement best practices of product/process design and development for supporting R&D of technologies that are likely to evolve rapidly, sustaining and safeguarding competitive advantage. Overall, then, this study, for the first time to our knowledge, begins the process of clarifying and generalizing, as far as possible, the role of long-run coevolution between host and parasitic technologies in complex systems, suggesting fruitful implications for innovation management. markets. This conceptual scheme here is especially relevant in Schumpeterian markets with innovation-based competition to explain a major source of technological evolution and success, the parasite-host relationships between technologies. Finally, this theory here suggests a new direction for the development of more sophisticated concepts and theoretical frameworks to explain technological and industrial change in economic systems.

Experimental studies of the performance of the heat-shielding layer of composite pipelines during cooling with liquid hydrogen

The development of technology for aircraft and rocket engines more efficient and environmentally friendly cryogenic fuels in the form of liquefied gases: hydrogen (vinyl), oxygen (oxide), natural gas (methane), required the creation of pipelines from modern composite materials, as well as new thermal insulation coatings (TIC), providing reliable protection of these highways from external heat leakage. Fuel out-of-flight manifolds of reusable aircraft require a particularly reliable TIC, since during the operation of the product, their multi-cycle cooling down occurs when pouring cryogenic fuel into the pipelines and heating at the discharge. Thermally insulating coatings in the form of polyurethane foam (PUF), applied to the surface of the protected product, by spraying or pouring a mixture of the constituent components, which are widely used at the present time, are not fully suitable for cryogenic pipelines due to the deterioration of their heat insulating properties in the process of cyclic cooling. The aim of the work is to create a new design and technological solution that ensures the performance of the TIC in the conditions of high-cycle thermal loading. In connection with the prospect of using cryogenic fuels in an aviation (reusable) technology, ensuring the performance of a TIC in such conditions is relevant. For the developed technology, experimental determination of the main parameters of the TIC was carried out. Composite pipelines of curvilinear and rectilinear shape were used as objects of research. The pipeline design included a sealing film sheath, a power sheath made of a polymer composite material, a foam heat insulating coating and metal connecting flanges. On model composite samples of cryogenic pipelines, cyclic tests for cooling with liquid hydrogen (filling of fuel lines) and heating to ambient temperature (draining components) were carried out. During the tests, the pipeline was first cooled with hydrogen gas for one hour. Then, for one hour, liquid hydrogen was poured into the internal cavity, after which natural warming up to a normal temperature was carried out for an hour. The obtained results allowed to determine the dependence of temperature and heat flow of the shell with TIC on the number of cooling cycles, to propose a design and technological solution for a significant reduction of the cryopump at large temperature differences in the TIC, to show the effectiveness of cyclic cooling of foam porosity with closed porosity of the “Vikort-3M”

An sequential optimization and aeroelastic constraint transformation method for strength-aeroelastic comprehensive design

With the development of modern aircraft technology, aeroelasticity plays a more and more crucial role in aircraft structural design. However, low efficiency of present aeroelastic analysis and optimization methods makes it difficult to apply in engineering practice. This paper presents a sequential optimization and aeroelastic constraint transformation method (SOACTM) for comprehensive design of airplane wings with strength and aeroelastic constraints. Optimization with structural strength constraint and aeroelastic constraint is transformed into a serial of cycles of decoupled structural strength sub-optimizations and aeroelastic sub-optimizations based on sequential optimization strategy. In structural strength sub-optimization, structural strength constraint is translated along its normal direction to make optimal design point satisfying aeroelastic constraint. And the goal of aeroelastic sub-optimization is to find the translational distance of structural strength constraint. Aeroelastic constraint is transformed to equivalent structural strength constraint via above approach. In this way, number of aeroelastic analyses in SOACTM is less than that in traditional optimization method and total computational time decreases. SOACTM is verified based on two examples. Traditional optimization method is applied for the sake of validation. The results demonstrated the accuracy and efficiency of SOACTM for wing comprehensive optimization considering both structural strength and aeroelastic constraints.

NASA electrified aircraft propulsion efforts

PurposeThis paper aims to review national aeronautics and space administration (NASA’s) broad investments in electrified aircraft propulsion (EAP). NASA investments are guided by an assessment of potential market impacts, technical key performance parameters, and technology readiness attained through a combination of studies, enabling fundamental research and flight research.Design/methodology/approachThe impact of EAP varies by market and NASA is considering three markets as follows: national/international, on-demand mobility and short-haul regional air transport. Technical advances in key areas have been made that indicate EAP is a viable technology. Flight research is underway to demonstrate integrated solutions and inform standards and certification processes.FindingsA key finding is that sufficient technical advances in key areas have been made, which indicate EAP is a viable technology for aircraft. Significant progress has been made to reduce EAP adoption barriers and further work is needed to transition the technology to a commercial product and improve the technology, so it is applicable to large transonic aircraft.Practical implicationsSignificant progress has been made to reduce EAP adoption barriers and further work is needed to transition the technology to a commercial product and improve the technology, so it is applicable to large transonic aircraft.Originality/valueThis paper will review the activities of the hybrid gas-electric subproject of the Advanced Air Transport Technology Project, the Revolutionary Vertical Lift Technology Project and the X-57 Flight Demonstration Project, and discuss the potential EAP benefits for commercial and military applications. This paper focuses on the vehicle-related activities, however, there are related NASA activities in air space management and vehicle autonomy activities, as well as a breakthrough technology project called the Convergent Aeronautics Solutions Project. The target audience is people interested in EAP.

Совместное алюминотермическое восстановление оксидов Zr, Ta и Nb

Alloys based on the Al-Zr system with insignificant Ta and Nb additives are in demand in the synthesis of complex alloys used to produce titanium alloys for aircraft and rocket technology. A common method for producing aluminum-zirconium alloys and ligatures is the out-of-furnace metallothermal reduction of zirconium from oxides and direct fusion of components. The practice of such methods has a number of significant disadvantages: poor separation of the metal and oxide phases, a low degree of extraction of the target component, the use of thermal additives, and the high cost of the resulting product. The solution to the problem may be a technology option where the temperature regime of the metallothermal reduction process is ensured both due to the heat of exothermic reactions and due to the additional supply of relatively inexpensive electrical energy. In this work, we investigated the possibility of obtaining alloys using metallothermal reduction from oxides based on ZrAl with Ta and Nb additives. An experimental technique for producing an alloy is presented. The data of X-ray phase analysis (XRD) and chemical analysis of the alloy. as well as an analysis of the content of oxygen and nitrogen in the alloy. X-ray phase analysis showed the formation of the ZrAl2 compound in all the studied alloys, as well as solid solutions (Zr4Nb)Al3, (Zr0.8Ta0.2)Al3, (Zr4Nb0.5Ta0.5)Al3 corresponding to the added element, ZrO2 is present in the 3 alloys, which tells us about not up to the reduced oxide Zr. These data are confirmed by analysis of the gas content in the alloy, where there is an increased oxygen content. The performed study can serve as a scientific basis for the development of promising metallothermal technologies for the production of rare metal alloys.

Outline of WEATHER-Eye Research Program to Protect Aircraft from Weather in Japan

The JAXA (Japan Aerospace Exploration Agency) is proceeding a research program “WEATHER-Eye” (Weather Endurance Aircraft Technology to Hold, Evade and Recover by Eye) which is to develop technology to ensure operational safety and efficiency against adverse weather. This research program consists of various cutting-edge research items. 1) Icephobic coating which utilizes Polytetrafluoroethylene has been developed and realized top level of water-repellant with 150 degrees in contact angle/10 degrees in falling angle. 2) Prototype of real time measurement sensor for runway snow condition has been developed. The sensor can measure type and depth of snow by using light scattering. Pilot will be able to make judgement of takeoff/landing on the base of snow condition. 3) The lightning risk will be estimated from weather information and can be mapped geographically. Pilots can select flightpath of aircraft and avoid lightning strikes if potential risk of lightning strikes on aircraft will be known in advance. 4) The CFRP (Carbon Fiber Reinforced Plastic) materials, which are widely used for aircraft, tend to have severe damage unlike metal materials when lightning strike are received because plastic materials are difficult to conduct electricity and discharge. New CFRP material with high electrical conductivity has been developed to minimize damage by lightning strike. Less damage has been shown by test specimen against lightning. 5) Ice accumulation inside engine will cause damage and thrust loss to engine. 3D blade configuration is applied for anti-icing and numerical CFD simulations show good performance. A heating concept blade is also shown. Volcanic ash causes damage to the fan or turbine due to erosion (friction and damage caused by the intake of fine particles) when ash enters a jet engine. Numerical analysis methods and test apparatus have been developed to analyze erosion phenomena. These will lead to improve resistance to erosion.

Overview of Quiet Supersonic Flights 2018 (QSF18) in Galveston, Texas

NASA and partners planned and executed the Quiet Supersonic Flights 2018 (QSF18) test program in Galveston, TX. The primary goal was to successfully engage a community, unaccustomed to hearing sonic booms, in a multiweek test of quiet supersonic flights. Secondary goals included assessing community survey methods and methods for sonic boom exposure determination. This presentation provides an overview of test planning, test execution, data analysis methods, dose-response results, and lessons learned. All of these elements inform future community response testing with NASA's X-59 Quiet Supersonic Technology (QueSST) aircraft.

Comparison of the supervisory cost of using an unmanned aerial system and conventional methods in construction projects

Unmanned Aerial Systems (UAS) are a growing aircraft technology being used in all sorts of industries. Despite studies exploring the potential applications of UAS, such as photographs or video collected by UAS, its benefits for the supervisory job on construction sites is not well understood. This paper presents a comparison of the supervisory cost generated using UAS and that from the conventional method. In this study, both five projects applying UASs and another five using the conventional supervisory method participated voluntarily. The survey used questionnaires targeted to people working in a supervisory job within the five projects. The results showed that most potential applications were particularly suited for tracking and monitoring job progress, evaluating safety monitoring and support, and inspecting difficult areas. In comparison, it was found that applying UAS was more cost-effective than the conventional supervisory method. The average supervisory cost to total wage generated from the project supervisory job by applying UAS and conventional methods were 0.212% and 0.450% respectively. Despite insignificant differences, the study provided a picture that, by applying UAS properly, it would be able to have a potential cost saving in the supervisory job in construction.

Design of experiments: X-59 sonic thump carpets in the eastern United States

NASA is conducting a series of computational experiments to quantify atmospheric effects on low noise sonic booms. In the current study, simulated cruise nearfield pressure data from NASA’s X-59 Quiet Supersonic Technology aircraft were propagated from the aircraft to the ground at four cardinal headings through five years of realistic atmospheric profiles at 30 locations across the eastern USA. Statistical design of experiments was used to select the locations where primary sonic thump carpet widths (CW) and metric levels at the ground were computed. Atmospheric profiles were taken from the Climate Forecast System Reanalysis database, which contains reanalyzed atmospheric profiles four times daily. Decision tree analyses were performed to determine relative importance of predictors for CW and metric levels. Predictors included were latitude, longitude, date, time of day, season, climate, aircraft heading, and ground elevation. Results of this study indicate the propagation resolution needed to adequately characterize the distributions of CW and ground metric data in terms of the necessary separation distance between propagation locations and the total number of atmospheres through which to propagate. This resolution will be used for a follow-on study of simulated X-59 carpets across the entire US mainland.

The potential impacts of Emissions Trading Scheme and biofuel options to carbon emissions of U.S. airlines

To reduce carbon emissions, the European Union has implemented the Emissions Trading Scheme (ETS) since 2012 for intra-European commercial flights. In response, airlines have explored various means, including sustainable jet fuels. This article investigates how similar ETS policy would affect domestic carbon emissions when implemented in the United States. The study integrates a model of airlines operations optimization and multi-feedstock biojet fuels life cycle assessment to simulate decisions of biojet fuel and commercial aviation industry responding to an emission policy. We conduct a Monte-Carlo simulation on two scenarios of domestic emission schemes to investigate the adoption of biojet fuels and its impacts on carbon emissions. Our model indicates that implementing an emission policy for U.S. airlines could incentivize adoption of biofuels - a median value of 10% of total fuels in 2050- while only marginally reduce travel demand. Because of a combined effect of emission policy and improved aircraft technology, the emissions in 2050 would only increase 1.37 times the 2005 level despite passenger demand grows by a factor of 2.75. A non-parametric sensitivity analysis suggests that the price of oil, economic growth, and carbon price are the three most significant factors in affecting the fleet-level carbon emissions.

Performance evaluation of multi-phase permanent magnet synchronous motor based on different winding configurations and magnetization patterns

Permanent magnet synchronous motor (PMSM) is the most reliable and efficient machine that widely used in robotics and automation, industrial applications, electric vehicles, home appliances, aircraft and aerospace technology due to its high efficiency, good dynamic performance and high torque density. In this paper, the influence of various types of winding configuration and different magnetization patterns in the performance of a five-phase PMSM is investigated. Three types of magnetization patterns such as radial magnetization (RM), parallel magnetization (PaM), and multi-segmented Halbach magnetization (SH) are applied to the five-phase 10-slot/4-pole PMSM during open-circuit and on-load conditions. A 2D finite element method (FEM) is intensively used in this investigation to model and predict the electromagnetic characteristics and performance of the PMSM. The detailed results from the finite-element analysis (FEA) on the cogging torque, induced back-emf, airgap flux density and electromagnetic torque are analysed. The induced back-emf of the machine is computed further into its harmonic distortions. Additionally, the skewing method for minimization of cogging torque of PMSM is proposed. From the results, it is observed that the five-phase, 10-slot/4-pole PMSM with double layer distributed winding and parallel magnetization gives the best machine performance.

Carbon offsetting and reduction scheme with sustainable aviation fuel options: Fleet-level carbon emissions impacts for U.S. airlines

To reduce aviation carbon emissions, the International Civil Aviation Organization initiated the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), which will take effect in 2021. In response, airlines have taken measures through various means, including the use of sustainable fuels. This article investigates the potential effects of a CORSIA-type policy when implemented in the United States. The study uses a combined model of airlines operations and multi-feedstock sustainable aviation fuels (SAFs) to represent decisions of several actors, such as farmers, bio-refineries, airlines, and policymakers. The research employed a life-cycle assessment and Monte-Carlo simulation to evaluate two policy scenarios on the amount of SAF consumption and the resulting emissions. Implementing a CORSIA-type policy could stimulate the demand and production of SAFs, while also reducing air travel growth by increasing airfare. As a result of this combined effect and improved aircraft technology, there is a 3.5% chance that the U.S. airlines industry can reduce greenhouse gas (GHG) emissions by 37.5–50% by the year 2050, compared to the 2005 emission levels. Despite a projected increase in air travel in 2050 by a factor of 2.75 (the median value), the emissions in 2050 are expected to rise to only 120% (the median value) of the 2005 level. The price of petroleum-based aviation fuels followed by the growth rate of the carbon price are the two most important factors to determine whether the CORSIA-type policy would achieve the emission reduction target.

Review of advanced low-emission technologies for sustainable aviation

Turbofan engines are the most widely used propulsion technology in commercial transport aircraft and are directly involved in many of the environmental impacts of aviation. Advancements in turbofan technology have thus a very significant potential in reducing aviation impacts on the environment. This article reviews the main technological advances currently being pursued in low-emission aircraft propulsion including: combustion and thermofluidic enhancements, gearbox technology, lightweight materials and intelligent engine health management systems. The paper discusses some key opportunities and challenges for these new technologies, with a particular outlook on the historical emission trends. Particularly, historical records from the ICAO aircraft engine emissions databank are used to extrapolate current trends and the progress against the ambitious targets set by international bodies. The analysis highlights that the sustained investments made by the aviation industry have yielded progressively diminishing returns and that the emission objectives will not be achieved at the current pace. Disruptive technological advances will therefore be required to significantly improve the fuel efficiency and mitigate environmental impact of commercial transport aircraft in the future.

Improving future low-noise aircraft technologies using experimental perception-based evaluation of synthetic flyovers.

Residents living in the vicinity of airports are exposed to noise from departing and approaching aircraft. Noise may be reduced by introducing novel aircraft technologies into vehicle retrofit, aircraft design and flight procedures. Nowadays, noise assessment and communication of noise are accomplished using conventional noise indicators that consider neither the perception of sound, nor its health effects. To overcome these limitations, this article presents a more comprehensive approach that supports the movement for perception-influenced design in order to reduce the negative environmental impacts and adverse health effects caused by increased air traffic noise. By means of auralization (the acoustical counterpart of visualization), possible future changes can be evaluated by considering the human perception of sound. In this study, in a virtual acoustic environment flyovers of different aircraft types and flight procedures are auralized for ground-based receiver locations, and subsequently evaluated in a psychoacoustic laboratory experiment with respect to short-term noise annoyance. Flight approaches of an existing reference aircraft, a possible low-noise retrofitted vehicle and a future low-noise vehicle design were simulated along standard and tailored flight procedures. To create realistic listening experiences of synthetic flyovers, auralization technologies were further developed regarding source synthesis, transitions between aircraft conditions, sound propagation effects and immersive sound reproduction. Listening experiments revealed significant annoyance reductions for low-noise aircraft types and tailored flight procedures, and that maximum benefit is achieved by the combined optimization of aircraft design and flight procedure. Further, it is shown that spatially distributed receivers need to be considered for a reliable low-noise aircraft technology evaluation. The reduction potential in terms of perceived noise by retrofitting current vehicles and designing new vehicle architectures is thus demonstrated. These findings suggest applying the proposed comprehensive approach to effectively reduce the impact of perceived air traffic noise in the future.