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Journal articles on the topic 'Flight Efficiency'
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Harada, Akinori, Tooru Ezaki, Tomoaki Wakayama, and Koichi Oka. "Air Traffic Efficiency Analysis of Airliner Scheduled Flights Using Collaborative Actions for Renovation of Air Traffic Systems Open Data." Journal of Advanced Transportation 2018 (June 7, 2018): 1–14. http://dx.doi.org/10.1155/2018/2734763.
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The increase in air traffic worldwide requires improvement of flight operational efficiency. This study aims to reveal the potential benefits, namely, savings on fuel consumption and flight time, which are expected for Japanese airspace, by statistically evaluating the operational efficiency defined by average differences of fuel consumption, flight time, and flight distance between the original and the optimized flight of domestic flights in Japan. The aircraft position and time data used in this study were obtained from Collaborative Actions for Renovation of Air Traffic Systems Open Data—the radar data released by the Japan Civil Aviation Bureau. Flight information, such as air data and fuel flow, is estimated by applying meteorological data and aircraft performance model to the position information of radar data. Each reconstructed trajectory is optimized in terms of flight fuel consumption and flight time with an assumed cost index (CI). Dynamic programming is used as the trajectory optimization method. The flight fuel consumption and flight time of the optimized flight are compared with the original values to evaluate the operational efficiency. Herein, approximately one-third of 1-day data, i.e., 1087 cases of four aircraft types, are analyzed with reasonable CI settings. Our research findings suggest that flight fuel consumption and flight distance can be saved by 312 kg and 19.7 km, respectively, on average for the object flights. Following a statistical comparison between the original and the optimized flights, it was observed that two types of features, namely, flying on a detoured path and flying with nonoptimal altitude and speed in the cruise phase, are major factors which deteriorate the total operational efficiency in terms of fuel consumption, flight time, and flight distance.
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Wang, Z. J. "Efficiency of flapping flight." Journal of Biomechanics 39 (January 2006): S357. http://dx.doi.org/10.1016/s0021-9290(06)84426-x.
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Pobezhimov, V. N. "Flight efficiency of a pulsejet." Russian Aeronautics (Iz VUZ) 53, no. 1 (March 2010): 77–80. http://dx.doi.org/10.3103/s1068799810010137.
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Natiq qızı Nurullazadə, Fidan. "Evaluation of flight conditions at tropopause level." NATURE AND SCIENCE 07, no. 02 (April 23, 2021): 49–52. http://dx.doi.org/10.36719/2707-1146/07/49-52.
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High-quality organization of meteorological support along the flight routes, increasing its efficiency depends on many factors. These factors include the moderate and high intensity turbulence observed in the middle and upper flight echelons, icing, jet streams, volcanic ash clouds and their distribution areas, tropopause level, its altitude, and others. In the pre-flight preparation phase, the meteorological body provides meteorological support for all types of domestic and international flights planned in the middle and upper troposphere. The organization of flight efficiency and economic profitability depends on the high-quality forecast of the above-mentioned meteorological factors. The article analyzes the characteristics of weather conditions that affect flights in the middle and upper troposphere. The main recommendations and requirements of Annex 3 (ANEX 3) and its amendments (Amendment 79), ICAO's guidelines for meteorological support for international air navigation, are relevant to many of the issues discussed in this article. Key words: turbulence, jet stream, volcanic ash, aircraft, tropopause, aviation, flight echelon, pressure, wind, temperature, meteorological support, flight route
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HARADA, Akinori, Tomoyuki KOZUKA, Yoshikazu MIYAZAWA, Navinda Kithmal WICKRAMASINGHE, Mark BROWN, and Yutaka FUKUDA. "Quantitative Operational Flight Efficiency Analysis of Passenger Aircraft Scheduled Flight." AEROSPACE TECHNOLOGY JAPAN, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES 14 (2015): 171–78. http://dx.doi.org/10.2322/astj.14.171.
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Meric, Ozlem Sahin. "Optimum Arrival Routes for Flight Efficiency." Journal of Power and Energy Engineering 03, no. 04 (2015): 449–52. http://dx.doi.org/10.4236/jpee.2015.34061.
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Henningsson, Per, and Richard J. Bomphrey. "Span efficiency in hawkmoths." Journal of The Royal Society Interface 10, no. 84 (July 6, 2013): 20130099. http://dx.doi.org/10.1098/rsif.2013.0099.
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Flight in animals is the result of aerodynamic forces generated as flight muscles drive the wings through air. Aerial performance is therefore limited by the efficiency with which momentum is imparted to the air, a property that can be measured using modern techniques. We measured the induced flow fields around six hawkmoth species flying tethered in a wind tunnel to assess span efficiency, e i , and from these measurements, determined the morphological and kinematic characters that predict efficient flight. The species were selected to represent a range in wingspan from 40 to 110 mm (2.75 times) and in mass from 0.2 to 1.5 g (7.5 times) but they were similar in their overall shape and their ecology. From high spatio-temporal resolution quantitative wake images, we extracted time-resolved downwash distributions behind the hawkmoths, calculating instantaneous values of e i throughout the wingbeat cycle as well as multi-wingbeat averages. Span efficiency correlated positively with normalized lift and negatively with advance ratio. Average span efficiencies for the moths ranged from 0.31 to 0.60 showing that the standard generic value of 0.83 used in previous studies of animal flight is not a suitable approximation of aerodynamic performance in insects.
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Takahashi, Hidemi, Mitsuru Kurita, Hidetoshi Iijima, and Monami Sasamori. "Interpolation of Turbulent Boundary Layer Profiles Measured in Flight Using Response Surface Methodology." Applied Sciences 8, no. 11 (November 21, 2018): 2320. http://dx.doi.org/10.3390/app8112320.
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Turbulent boundary layer profiles on the aircraft surface were characterized by pitot-rake measurements conducted in flight experiments at high subsonic Mach number ranges. Due to slight variations in atmospheric air conditions or aircraft attitudes, such as angles of attack and absolute flight speeds at different flights even under the same premised flight conditions, the boundary layer profiles measured at different flights can exhibit different shape and velocity values. This concern leads to difficulty in evaluating the efficiency of using some kind of drag-controlling device such as riblets in the flight test, since the evaluation would be conducted by comparing the profiles measured with and without using riblets at different flights. An approach was implemented to interpolate the boundary layer profile for a flight condition of interest based on the response surface method, in order to eliminate the influence of the flight conditional difference. Results showed that the interpolation with the 3rd-degree response surface model with a combination of two independent variables of flight Mach number and total pressure successfully eliminated the influence of the flight conditional difference, and interpolated the boundary layer profiles measured at different flights within an inaccuracy of 4.1% for the flight Mach number range of 0.5 to 0.78.
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Ellington, C. P. "Power and efficiency of insect flight muscle." Journal of Experimental Biology 115, no. 1 (March 1, 1985): 293–304. http://dx.doi.org/10.1242/jeb.115.1.293.
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The efficiency and mechanical power output of insect flight muscle have been estimated from a study of hovering flight. The maximum power output, calculated from the muscle properties, is adequate for the aerodynamic power requirements. However, the power output is insufficient to oscillate the wing mass as well unless there is good elastic storage of the inertial energy, and this is consistent with reports of elastic components in the flight system. A comparison of the mechanical power output with the metabolic power input to the flight muscles suggests that the muscle efficiency is quite low: less than 10%.
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McLaughlin, Robert L., and Robert D. Montgomerie. "Flight speeds of parent birds feeding nestlings: maximization of foraging efficiency or food delivery rate?" Canadian Journal of Zoology 68, no. 11 (November 1, 1990): 2269–74. http://dx.doi.org/10.1139/z90-316.
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We examined the flight behaviour of female Lapland longspurs (Calcarius lapponicus) foraging during the nestling period to determine whether they flew at speeds maximizing the overall rate of energy delivery to their nestlings (VY), or at speeds maximizing the distance travelled per unit energy expended (Vmr), as predicted by different models. The average flight speed of females was slower when they flew to closer feeding sites, suggesting that acceleration was an important component of these flights. We therefore included the cost of acceleration into the flight-speed models. Longspurs flew slightly faster, on average, than our predicted speeds for maximizing the distance travelled per unit energy expended (Vmr) but substantially lower than our predicted speeds for maximizing the overall rate of energy delivery to nestlings (VY). The fact that longspurs did not fly faster at times of increased food availability is also consistent with maximizing the distance travelled per unit energy expended, but not with maximizing the overall rate of energy delivery. Based on other studies of parent birds feeding young, we expected that longspurs would adjust their flight speeds to maximize the overall rate of energy delivery to their young. Instead, their flight behaviour was more consistent with maximizing foraging efficiency (the ratio of energy collected to energy spent).
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Sugiyanto, Gito, Purwanto Bekti Santosa, Jajang, Ari Fadli, and Mina Yumei Santi. "Evaluation of hub-spoke airport networks in Sumatra island, Indonesia to increase efficiency of air transportation." MATEC Web of Conferences 195 (2018): 04009. http://dx.doi.org/10.1051/matecconf/201819504009.
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Kualanamu International Airport is the busiest airport in Sumatra. In 2015, it served 8 million passengers and 41.6 thousand tons of goods for international and domestic flights. Hub-spoke networks are optimized when generally having a transport efficiency of at least 49-52% as well as providing air service in a wide geographic area and to many destinations. The aim of this study is to analyse the hub-spoke airport networks based on the Herfindahl-Hirschmann Index (HHI) to increase air transport efficiency in Sumatra Island. This study uses data from cargo production and couple’s flights from 10 airports in Sumatra Island for domestic flight route pairs and 6 airports for international flight route pairs. The results of the study show that route networks in Sumatra Island in existing conditions have not developed with the hub-spokes concept. The HHI analysis, indicates 2 hubs for domestic flights and 1 hub (Kualanamu) for international flights. Kualanamu International Airport and Hang Nadim International Airport were indicated as hub airports in Sumatra Island for domestic flights. The efficiency of air cargo transportation through the system (2 hubs and 8 spokes) results in a transport efficiency at 68.37%, which is still far above the efficient range at 49-52%.
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Langelaan, Jack W., Anjan Chakrabarty, Aijun Deng, Kirk Miles, Vid Plevnik, Jure Tomazic, Tine Tomazic, and Gregor Veble. "Green Flight Challenge: Aircraft Design and Flight Planning for Extreme Fuel Efficiency." Journal of Aircraft 50, no. 3 (May 2013): 832–46. http://dx.doi.org/10.2514/1.c032022.
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Emboaba Moreira, Mauricio, José Alexandre Guerreiro Fregnani, Kemp Harker, and Alexander Vrtiska. "An overall assessment of the fuel consumption efficiency of the domestic flights in Brazil (Period 2000-2015)." Journal of Airline and Airport Management 8, no. 1 (September 4, 2018): 1. http://dx.doi.org/10.3926/jairm.117.
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Purpose: The aim of this article is to analyze the evolution of fuel consumption efficiency of the domestic flights in Brazil along the period 2000-2015 in order understand the overall efficiency of the aeronautical infrastructure in this country.Design/methodology: This article proposes a method for high level assessments of the aeronautical infrastructure efficiency (either on ground or airspace) in a fast and easy to grasp manner, using the key performance indicator of useful distance per flight hour. The method estimates the average flight time spent by the national carriers to accomplish the average stage lengths in each year of the period 2000-2015 and compare these results with the flight time baseline included in the flight planning data of the aircrafts composing the Brazilian commercial aircraft fleet.Findings: This approach leads to huge differences between the referred results and the fuel consumption shown by flight operations manuals and were attributed to the inefficiencies existing in the acknowledged overloaded aeronautical infrastructure (either in the air or on ground) in Brazil. With that it is concluded that there is a potential reduction opportunity of almost 30% in aircraft fuel consumption in domestic flights in Brazil, which has been until the moment almost unconsidered. Thus, government policy-makers and all stakeholders will be able to quantify the impacts and recommend investments in infrastructure in a well-founded way. Furthermore, the return on investments of public funds, which are especially scarce in the developing countries, will be assessed in a simple manner. Under this scope investments and research on Air Traffic Management (ATM) new technologies and flow management techniques are strongly suggested in order to improve airspace operational efficiency.Originality/value: A new and innovative method for high level assessment of the aeronautical infrastructure efficiency.
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Jankowski, Antoni, and Mirosław Kowalski. "Start-up processes’ efficiency of turbine jet engines." Journal of KONBiN 40, no. 1 (December 1, 2016): 63–82. http://dx.doi.org/10.1515/jok-2016-0041.
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Abstract The paper presents diagnoses of example start-up processes of drive units built in military aircraft operated in the Dęblin's “School of Eaglets” during the flight. The significance of this process is very important, especially from the point of view of flight safety, especially as it concerns the training aircraft, on which officer cadets-candidates for pilots are trained. The diagnosis of the start-up process was conducted using data from on-board flight recorders recorded during a flight training, whose aim was an emergency launch of particular drive units, and with the help of the so-called phase mapping of the selected operating parameters of the particular flight drive systems. The standard diagram of typical start-up systems was shown, while presenting their base subassemblies. At the end, the obtained results and the main problems that need intervention were commented, as well as further preventive activities were proposed.
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Sahin, Ozlem, Oznur Usanmaz, and Enis T. Turgut. "An assessment of flight efficiency based on the point merge system at metroplex airports." Aircraft Engineering and Aerospace Technology 90, no. 1 (January 2, 2018): 1–10. http://dx.doi.org/10.1108/aeat-06-2016-0097.
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Purpose Metroplex is a system of two or more airports, in physical proximity, with highly interdependent arrival and departure operations. The purpose of this study is the construction of an efficient and effective air route model based on the point merge system (PMS) to reduce aircraft fuel consumption and CO2 emissions for three metroplex airports in Istanbul terminal control area (TMA). Design/methodology/approach A PMS arrival route model is constructed for metroplex airports. In the proposed model, two situations are taken into consideration: for delay which can be defined as flying on sequencing legs (PMSdel) and for no delay (PMSno del). An empirical model is developed using a data set including the flight data records of ten actual B737-800 domestic flights. With this empirical model, both the baseline and the PMS models (PMSdel and PMSno del) are compared in terms of fuel consumption, CO2 emissions and flight distance and time as a theoretical computation. Findings In the proposed PMSno del arrival route model, according to different entry points for Istanbul Ataturk International Airport (LTBA), the analyses show an average reduction of 26 per cent in flight time, 24.5 per cent in flight distance, 17 per cent in fuel burned and CO2 emissions; in addition, for Sabiha Gökcen International Airport (LTFJ) there are 34, 23 and 32 per cent average savings for flight time, flight distance and fuel burned together with CO2 emissions obtained, respectively. Even if the PMSdel model, for LTFJ except only one entry point, for LTBA except two entry points, better results are obtained than baseline. Practical implications The point merge model for metroplex airports in this paper can be applied by airspace designers and Air Navigation Service Providers to perform efficient and effective arrival routes. Originality/value In this study, a point merge model is constructed for metroplex airports. Quantitative results, using an empirical model, are achieved in terms of fuel consumption, CO2 emissions and flight distance and time at metroplex airports.
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Shevchuk, Stanislav O., and Sergey V. Barsukov. "INCREASING EFFICIENCY OF NAVIGATION MAINTANANCE OF AERIAL GEOPHYSICS." Interexpo GEO-Siberia 1, no. 2 (July 8, 2020): 140–49. http://dx.doi.org/10.33764/2618-981x-2020-1-2-140-149.
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New features of navigation complex RouteNav created with the authors’ collaboration are considered. The feature of partly-done routes allows optimizing survey of routes and fulfill them by parts with returns if it is necessary. The feature of direction-control excludes the problems with the flight direction changes to wrong during the route tracing. Also the flight-project utilities are improved with new special features, such as automatic generation of calibration routes (for compensation of magnetometer deviations) and cloning of compound routes allows, which is to increase automation level of flight planning. Implementation of these features is considered in the article. The provided capabilities of RouteNav can be considered as a competitive advantage over the devices and complexes used for similar purpose in aerial geophysics. Increasing efficiency of navigation is reached because of user-friendly interface, which allows the pilot to trace the routes by oneself, and also because of flight optimization and control capabilities and flight-planning features.
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Jia, Meng, and Yingbao Yang. "Cross-emotional infection among multi-flight groups in mass flight delays." Kybernetes 45, no. 10 (November 7, 2016): 1589–603. http://dx.doi.org/10.1108/k-01-2016-0003.
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Purpose The purpose of this paper is to study dynamic evolution of passenger emotional contagion among different flights emerging in mass flight delays, so as to quantitatively analyze emotional variation tendencies and influences of concerned factors and intervention measures. Design/methodology/approach An intervening variable of group emotion was introduced into emotional contagion model to simulate passenger emotional evolution among multi-flight groups. Besides, personalities, characters and social relationships were considered to represent individual differences in emotional changes. Based on personal contact relationships, emotional contagion model was proposed to evaluate cross-emotion transition processes among different groups under scenarios of information shortage. Eventually, evolutionary processes of passenger emotions were fused in an agent-based simulation based on social force correction model. Findings Simulation experiment results revealed that passenger emotions suffer from combined impacts of individual emotional changes and emotional interactions among adjacent flights through a comparison with actual survey. Besides, emotional interactions accelerate processes of emotion transitions, and have significant impacts on adjacent flights when different measures are taken. Moreover, taking intervention measures simultaneously seems more effective than implementing intervention successively. Originality/value The proposed method makes up for deficiency of ignoring effects of emotional interactions among adjacent flights. It contributes to providing control methods and strategies for relevant departments and improving the efficiency and ability of handling passenger collective events in mass flight delays.
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Izyumov, Andrey, Ekaterina Vasilyeva, Oleg Ostapovich, and Egor Alentsov. "Energy efficiency analysis of modern delivery drones." E3S Web of Conferences 279 (2021): 01028. http://dx.doi.org/10.1051/e3sconf/202127901028.
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The research performed is dedicated to the problem of energy efficiency analysis of modern delivery drones. 12 models are chosen to provide a statistical calculations of the average ratio of mass and flight range of the drone. The method of least squares is used to analyze trends. The conclusion is made that the most successful companies apply the similar ratio of mass and flight range. The most successful drones of such companies are able to carry from 1.3 to 2.27 kg of cargo and have a flight range from 10 to 24 km. That allows to judge about the energy efficiency of these devices.
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Jauhiainen, J., S. Aksela, and E. Nõmmiste. "Flight time distribution and collection efficiency studies for time-of-flight mass spectrometer." Physica Scripta 51, no. 5 (May 1, 1995): 549–56. http://dx.doi.org/10.1088/0031-8949/51/5/002.
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Alla, Hajar, Lahcen Moumoun, and Youssef Balouki. "A Multilayer Perceptron Neural Network with Selective-Data Training for Flight Arrival Delay Prediction." Scientific Programming 2021 (June 14, 2021): 1–12. http://dx.doi.org/10.1155/2021/5558918.
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Flight delay is the most common preoccupation of aviation stakeholders around the world. Airlines, which suffer from a monetary and customer loyalty loss, are the most affected. Various studies have attempted to analyze and solve flight delays using machine learning algorithms. This research aims to predict flights’ arrival delay using Artificial Neural Network (ANN). We applied a MultiLayer Perceptron (MLP) to train and test our data. Two approaches have been adopted in our work. In the first one, we used historical flight data extracted from Bureau of Transportation Statistics (BTS). The second approach improves the efficiency of the model by applying selective-data training. It consists of selecting only most relevant instances from the training dataset which are delayed flights. According to BTS, a flight whose difference between scheduled and actual arrival times is 15 minutes or greater is considered delayed. Departure delays and flight distance proved to be very contributive to flight delays. An adjusted and optimized hyperparameters using grid search technique helped us choose the right architecture of the network and have a better accuracy and less error than the existing literature. The results of both traditional and selective training were compared. The efficiency and time complexity of the second method are compared against those of the traditional training procedure. The neural network MLP was able to predict flight arrival delay with a coefficient of determination R 2 of 0.9048, and the selective procedure achieved a time saving and a better R 2 score of 0.9560. To enhance the reliability of the proposed method, the performance of the MLP was compared with that of Gradient Boosting (GB) and Decision Trees (DT). The result is that the MLP outperformed all existing benchmark methods.
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Zieja, Mariusz, Henryk Smoliński, and Paweł Gołda. "Estimating the system efficiency to ensure aircraft flight safety." Journal of KONBiN 36, no. 1 (December 1, 2015): 115–22. http://dx.doi.org/10.1515/jok-2015-0061.
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Abstract In the article was presented approach logical - probabilistic to assess the efficiency of the flight safety assurance system of aircraft considering that it is justified by the random nature of the process, which describe the indicators and logic is necessary during qualifying the threats and prevent such threats. Was proposed a method of quantitative estimation of system efficiency based on data and information collected in the information systems exploited in the Air Force. Was presented an analytical method for determining the probability of counteracting by the pilot emergency situation in-flight in cases where we have relevant data on the risks of flight safety. The probability of counteracting by the pilot emergency situation in-flight is even greater the higher the expected value and the lower the variance.
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Kammoun, Mohamed Ali, Sadok Turki, and Nidhal Rezg. "Optimization of Flight Rescheduling Problem under Carbon Tax." Sustainability 12, no. 14 (July 10, 2020): 5576. http://dx.doi.org/10.3390/su12145576.
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The flight rescheduling problem is one of the major challenges of air traffic issue. Unforeseen bad weather conditions stimulate air traffic congestion and make the initial scheduling infeasible, resulting in significant economic losses for passengers and airlines. Furthermore, due to rigorous environmental legislations, flight rescheduling becomes a more complicated problem, as it has to deal with flight delays on the one hand, and carbon emissions on the other hand. In this paper, we address the flight rescheduling problem with an environmental requirement subject to the air capacity limitation due to bad weather conditions. A new strategy is proposed to minimize the disruption effects on planned flights, which adopted ground delay, longer route change, flight cancellation, as well speed adjustment to arrive at a scheduled time. Firstly, the objective of this study is to determine the economical flights plan in line with the new available air capacity. Secondly, by considering the environmental impact of the kerosene consumption, we illustrate the contribution of an economical decision to aircraft emissions. Experiment results are provided to show the efficiency of the proposed strategies and genetic algorithm as the used optimization method. Furthermore, the impacts of carbon tax and cost of arrival delay on the flights carbon emissions are studied.
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Welham, Clive V. J., and Ronald C. Ydenberg. "Efficiency-Maximizing Flight Speeds in Parent Black Terns." Ecology 74, no. 6 (September 1993): 1893–901. http://dx.doi.org/10.2307/1939946.
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Schwaiger, Meinhard, and David Wills. "D-Dalus VTOL – efficiency increase in forward flight." Aircraft Engineering and Aerospace Technology 88, no. 5 (September 5, 2016): 594–604. http://dx.doi.org/10.1108/aeat-04-2015-0104.
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Purpose This paper aims to provide the international aeronautical community with details of the development of a new disruptive technology for aircraft propulsion. Design/methodology/approach This paper describes the results achieved by a small Austrian aeronautical innovations company in developing a cyclogyro propulsion system capable of vertical launch and efficient forward flight. The research team progressed from concept definition and simulation (2004-2006), through experimental validation and concept demonstration (2006), component optimization (2006-2012), full system demonstration (2012-2014) and examination of ability to scale (both larger and smaller) (2015 onwards). This paper provides details of the results of each of these stages. Findings The research team proved that cyclogyro propulsion can be used for the vertical launch, and that, in forward flight, it has the potential to achieve efficiency beyond the range of conventional fixed wing and rotorcraft. Research limitations/implications This research indicates that the efficiency increases with forward speed within the range achieved in standard wind tunnels (up to 35 m/s). This efficiency appears to be caused by a unique chamber effect within the cyclogyro rotor assembly. Future research should be conducted to analyse this chamber effect in greater detail and to test the cyclogyro rotor for speeds beyond 35 m/s. Practical implications This work indicates that cyclogyro propulsion could have the potential to provide vertical launch, high speed and highly efficient aircraft that have reduced wing span, no external rotors and exceptional agility. This technology could therefore be feasible for vertical take-off and landing aircraft that can safely form densely packed swarms. Social implications It could be researched as an efficiency increase in forward flight completely different to existing propulsion systems. This could open a way for a more efficient air traffic in future and faster reduction of CO2 and NOX emission an allow an environment-friendlier air travelling. Originality/value This paper provides the details of the first cyclogyro aircraft to have flown and will serve the aeronautical community by stimulating the debate on this new disruptive technology.
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Jeong, Taikyeong, and Anthony Ambler. "Power efficiency system for flight application (pesfa) mission." IEEE Transactions on Aerospace and Electronic Systems 42, no. 4 (October 2006): 1515–20. http://dx.doi.org/10.1109/taes.2006.314592.
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Tiimus, Kristjan, Mikk Murumäe, Eero Väljaots, and Mart Tamre. "High-Efficiency Internal Combustion Engine Used in the Unmanned Aircraft." Solid State Phenomena 220-221 (January 2015): 928–33. http://dx.doi.org/10.4028/www.scientific.net/ssp.220-221.928.
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Unmanned aerial vehicles (UAVs) are used predominately for military applications, despite a growing number of emerging civilian tasks. One of the key tasks for increasing the advantages over a manned aircraft are to extend the flight duration of the UAV. Long endurance flights demand an engine that adapts to variable weather and atmospheric conditions as well as to changes in altitude. Varying demand of the UAV for power is compared to determine the needs for our mid-class test platform. The paper presents a solution to a high-efficiency engine and suggests a test layout for assessing reliability and optimal performance.
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Shi, Tongyu, Jinghan Lai, Runping Gu, and Zhiqiang Wei. "An Improved Artificial Neural Network Model for Flights Delay Prediction." International Journal of Pattern Recognition and Artificial Intelligence 35, no. 08 (March 24, 2021): 2159027. http://dx.doi.org/10.1142/s0218001421590278.
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With the limitation of air traffic and the rapid increase in the number of flights, flight delay is becoming more frequent. Flight delay leads to financial and time losses for passengers and increases operating costs for airlines. Therefore, the establishment of an accurate prediction model for flight delay becomes vital to build an efficient airline transportation system. The air transportation system has a huge amount of data and complex operation modes, which is suitable for analysis by using machine learning methods. This paper discusses the factors that may affect the flight delay, and presents a new flight delay prediction model. The five warning levels are defined based on flight delay database by using K-means clustering algorithm. After extracting the key factors related to flight operation by the grey relational analysis (GRA) algorithm, an improved machine learning algorithm called GRA — Genetic algorithm (GA) — back propagation neural network, GRA-GA-BP, is introduced, which is optimized by GA. The calculation results show that, compared with models before optimization and other two algorithms in previous papers, the proposed prediction model based on GRA-GA-BP algorithm shows a higher prediction accuracy and more stability. In terms of operation efficiency and memory consumption, it also has good performance. The analysis presented in this paper indicates that this model can provide effective early warnings for flight delay, and can help airlines to intervene in flights with abnormal trend in advance.
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Bao, Danwen, and Songyi Hua. "Flight Time and Frequency-Optimization Model for Multiairport System Operation." Mathematical Problems in Engineering 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/7371461.
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This study’s goal is to reduce the number of flights and alleviate congestion in hub airports. It proposes a flight time and frequency-optimization method for multiairport systems. A flight time and frequency-optimization model for multiairport system operation is created to minimize loss of passenger trip time. A k-means clustering algorithm is designed to solve the model and calculate indexes such as flight time and frequency, passenger trip-time loss, and distribution of airplane models and quantity. The calculation results of an example in China are as follows. Under multiairport system operation mode, passenger demands are divided into 7 categories; 11 flights satisfy all passenger demands; passenger trip-time loss is 129,573 min; and the average passenger load factor is 90.1%. Under an independent operation mode, passenger demands are divided into 8 categories; 13 flights satisfy all passenger demands; passenger trip-time loss is 173,705 min; and the average passenger load factor is 87.4%. The multiairport system operation mode not only improves passenger trip efficiency but also benefits airlines by improving the passenger load factor and reducing flights. Moreover, comparative analysis of a genetic algorithm versus a clustering algorithm further proves the accuracy of the clustering algorithm.
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Schellenberg, Ben, Tom Richardson, Arthur Richards, Robert Clarke, and Matt Watson. "On-Board Real-Time Trajectory Planning for Fixed Wing Unmanned Aerial Vehicles in Extreme Environments." Sensors 19, no. 19 (September 21, 2019): 4085. http://dx.doi.org/10.3390/s19194085.
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A team from the University of Bristol have developed a method of operating fixed wing Unmanned Aerial Vehicles (UAVs) at long-range and high-altitude over Volcán de Fuego in Guatemala for the purposes of volcanic monitoring and ash-sampling. Conventionally, the mission plans must be carefully designed prior to flight, to cope with altitude gains in excess of 3000 m, reaching 9 km from the ground control station and 4500 m above mean sea level. This means the climb route cannot be modified mid-flight. At these scales, atmospheric conditions change over the course of a flight and so a real-time trajectory planner (RTTP) is desirable, calculating a route on-board the aircraft. This paper presents an RTTP based around a genetic algorithm optimisation running on a Raspberry Pi 3 B+, the first of its kind to be flown on-board a UAV. Four flights are presented, each having calculated a new and valid trajectory on-board, from the ground control station to the summit region of Volcań de Fuego. The RTTP flights are shown to have approximately equivalent efficiency characteristics to conventionally planned missions. This technology is promising for the future of long-range UAV operations and further development is likely to see significant energy and efficiency savings.
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Kondroška, Vaidotas, and Jonas Stankūnas. "ANALYSIS OF AIRSPACE ORGANIZATION CONSIDERING AIR TRAFFIC FLOWS." TRANSPORT 27, no. 3 (September 19, 2012): 219–28. http://dx.doi.org/10.3846/16484142.2012.719199.
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Aviation is one of the most rapidly developing types of transport playing a crucial role in the modern world. Aviation has a sensitive response to any economic or social changes and painful aviation catastrophes. In spite of increasing the flows of passengers and flights, for certain reasons, the aviation system does not always satisfy the expectations of the airspace users in the sense of efficiency. The effectiveness of air transport operations is determined by both a reduction in the costs of every airspace user and the efficiency of the air traffic management system. Airspace organization performed by the air traffic management system, i.e. its adaptation to the performance of appropriate air navigation services, largely defines the efficiency of these services. Due to various reasons, presently, the area of airspace and airspace management has remained one of the largest and incompletely used aviation resources. Beside other appropriate means, the organization of air traffic management and airspace establishes flight conditions and determines the efficiency of flight trajectories and regularity. A comparison of air traffic management systems of different regions identifies the obstacles that do not allow ensuring the maximum results of flight efficiency in any place. One of the main reasons is the high fragmentation of the specified regions that mostly coincide with the state borders. The above reasons show that in order to efficiently develop aviation, the successful development of that to the extent of one country is not enough. Thus, the best results will only be reached solving the existing problems and intended challenges to the extent of a few countries – up to the extent of the whole region. The aim of research is to define a methodology allowing the organization of regional airspace according to the flows of air traffic and subsequently enabling to solve flight efficiency problems related to air traffic management. For space evaluation, the paper suggests using rectangular grids the application of which makes possible dividing the researched space more easily and exactly. Considering the examples of air traffic management systems demonstrating the best results of efficiency, it can be exactly assumed about the number of possible airspace blocks complying with the flows of flights in the analyzed airspace. In case, a preliminary number of the wanted clusters is known, it is purposeful to apply the method of the cluster analysis of K-means with necessary limitations to the formed building airspace blocks and to determine the optimum version taking into account the analyzed ones. The paper suggests representing points having appropriate weighted coefficients during the stage of clustering rather than using grid cells. The optimization of the obtained airspace blocks is necessary in case the formed blocks do not properly comply with the aims raised. The application of the methodology suggested in the paper enables dividing the airspace of a big territory into airspace blocks according to the flows of flights independent from the air way network, flight intensity and the collocation of the airspace elements of a special purpose.
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Hedh, Linus, Christopher G. Guglielmo, L. Christoffer Johansson, Jessica E. Deakin, Christian C. Voigt, and Anders Hedenström. "Measuring power input, power output and energy conversion efficiency in un-instrumented flying birds." Journal of Experimental Biology 223, no. 18 (August 13, 2020): jeb223545. http://dx.doi.org/10.1242/jeb.223545.
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ABSTRACTCost of flight at various speeds is a crucial determinant of flight behaviour in birds. Aerodynamic models, predicting that mechanical power (Pmech) varies with flight speed in a U-shaped manner, have been used together with an energy conversion factor (efficiency) to estimate metabolic power (Pmet). Despite few empirical studies, efficiency has been assumed constant across flight speeds at 23%. Ideally, efficiency should be estimated from measurements of both Pmech and Pmet in un-instrumented flight. Until recently, progress has been hampered by methodological constraints. The main aim of this study was to evaluate recently developed techniques and estimate flight efficiency across flight speeds. We used the 13C-labelled sodium bicarbonate method (NaBi) and particle image velocimetry (PIV) to measure Pmet and Pmech in blackcaps flying in a wind tunnel. We also cross-validated measurements made by NaBi with quantitative magnetic resonance (QMR) body composition analysis in yellow-rumped warblers. We found that Pmet estimated by NaBi was ∼12% lower than corresponding values estimated by QMR. Pmet varied in a U-shaped manner across flight speeds in blackcaps, but the pattern was not statistically significant. Pmech could only be reliably measured for two intermediate speeds and estimated efficiency ranged between 14% and 22% (combining the two speeds for raw and weight/lift-specific power, with and without correction for the ∼12% difference between NaBi and QMR), which were close to the currently used default value. We conclude that NaBi and PIV are viable techniques, allowing researchers to address some of the outstanding questions regarding bird flight energetics.
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Bomphrey, Richard J., Toshiyuki Nakata, Per Henningsson, and Huai-Ti Lin. "Flight of the dragonflies and damselflies." Philosophical Transactions of the Royal Society B: Biological Sciences 371, no. 1704 (September 26, 2016): 20150389. http://dx.doi.org/10.1098/rstb.2015.0389.
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This work is a synthesis of our current understanding of the mechanics, aerodynamics and visually mediated control of dragonfly and damselfly flight, with the addition of new experimental and computational data in several key areas. These are: the diversity of dragonfly wing morphologies, the aerodynamics of gliding flight, force generation in flapping flight, aerodynamic efficiency, comparative flight performance and pursuit strategies during predatory and territorial flights. New data are set in context by brief reviews covering anatomy at several scales, insect aerodynamics, neuromechanics and behaviour. We achieve a new perspective by means of a diverse range of techniques, including laser-line mapping of wing topographies, computational fluid dynamics simulations of finely detailed wing geometries, quantitative imaging using particle image velocimetry of on-wing and wake flow patterns, classical aerodynamic theory, photography in the field, infrared motion capture and multi-camera optical tracking of free flight trajectories in laboratory environments. Our comprehensive approach enables a novel synthesis of datasets and subfields that integrates many aspects of flight from the neurobiology of the compound eye, through the aeromechanical interface with the surrounding fluid, to flight performance under cruising and higher-energy behavioural modes. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’.
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Shao, Quan, Mengxue Shao, Yunpeng Bin, Pei Zhu, and Yan Zhou. "Flight Recovery Method of Regional Multiairport Based on Risk Control Model." Mathematical Problems in Engineering 2020 (April 29, 2020): 1–18. http://dx.doi.org/10.1155/2020/7105381.
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In the regional multiairport system, the contradiction between the limited operating resources and the large flight flow is serious, and the flight delays can easily lead to the occurrence of unsafe events. This paper investigates the abnormal flight recovery method in regional multiairport system based on risk control. The focus is to reschedule arrival-departure flights in real time with minimized delay time and risk probability. In this study, the risk about terminal area control and scene operation was considered in the analysis of the risk control model (RCM), which includes six key risk points: airspace control, flight conflict, ground service, apron support, ground control, and taxiing conflict. The mathematical model on flight recovery was constructed to solve minimized delay time and risk probability with MSINS (multistart algorithm with intelligent neighborhood selection). The data of a typical regional multiairport system in China were selected for experimental verification in order to compare the RCM with the traditional recovery model (TRM). The experimental results show that first, there are some hidden dangers in the traditional recovery methods of flight delay. Flight conflict and apron support are the risk points that need to be controlled most in the multiairport system. Secondly, for the effective solution with the shortest delay time, the RCM can reduce the overall operation risk of the system, but the flight delay time is a little longer. For the effective solution with the lowest risk probability, RCM can reduce the risk of system operation and the delay time of flights at the same time. Therefore, RCM can improve the security level of the system during abnormal flight recovery and ensure or even improve the recovery efficiency.
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Zheng, Pan, Si Ji Hu, and Wen Deng. "Airport Gate Assignment Model Based on Gate Occupied Efficiency." Advanced Materials Research 148-149 (October 2010): 377–84. http://dx.doi.org/10.4028/www.scientific.net/amr.148-149.377.
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Airport gate assignment is to appoint a gate for arrival or leave flight and to ensure that the flight is on schedule. Assigning the airport gate with high efficiency is a key task among the airport ground operation. As the core of airport operation, aircraft stands assignment is known as a kind of complicated combinatorial optimization problem. In this paper, occupied gates in order to optimize the efficiency of the target index, the purpose of parking gates in order to save the resource utilization and to improve the speed of flight at the same time working to meet the requirements of the quality of passenger services, An integer program (IP) model is developed, and a tabu search algorithm was put forward to resolve the model. The algorithm results in the calculation of time and extent to optimize the effectiveness of certain.
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Ward, S., U. Möller, J. M. V. Rayner, D. M. Jackson, D. Bilo, W. Nachtigall, and J. R. Speakman. "Metabolic power, mechanical power and efficiency during wind tunnel flight by the European starlingSturnus vulgaris." Journal of Experimental Biology 204, no. 19 (October 1, 2001): 3311–22. http://dx.doi.org/10.1242/jeb.204.19.3311.
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SUMMARYWe trained two starlings (Sturnus vulgaris) to fly in a wind tunnel whilst wearing respirometry masks. We measured the metabolic power (Pmet) from the rates of oxygen consumption and carbon dioxide production and calculated the mechanical power (Pmech) from two aerodynamic models using wingbeat kinematics measured by high-speed cinematography. Pmet increased from 10.4 to 14.9 W as flight speed was increased from 6.3 to 14.4 m s–1 and was compatible with the U-shaped power/speed curve predicted by the aerodynamic models. Flight muscle efficiency varied between 0.13 and 0.23 depending upon the bird, the flight speed and the aerodynamic model used to calculate Pmech. Pmet during flight is often estimated by extrapolation from the mechanical power predicted by aerodynamic models by dividing Pmech by a flight muscle efficiency of 0.23 and adding the costs of basal metabolism, circulation and respiration. This method would underestimate measured Pmet by 15–25 % in our birds. The mean discrepancy between measured and predicted Pmet could be reduced to 0.1±1.5 % if flight muscle efficiency was altered to a value of 0.18. A flight muscle efficiency of 0.18 rather than 0.23 should be used to calculate the flight costs of birds in the size range of starlings (approximately 0.1 kg) if Pmet is calculated from Pmech derived from aerodynamic models.
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Zhou, Hang, and Xinxin Jiang. "Research on Arrival/Departure Scheduling of Flights on Multirunways Based on Genetic Algorithm." Mathematical Problems in Engineering 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/851202.
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Aiming at the phenomenon of a large number of flight delays in the terminal area makes a reasonable scheduling for the approach and departure flights, which will minimize flight delay losses and improve runway utilization. This paper considered factors such as operating conditions and safety interval of multi runways; the maximum throughput and minimum flight delay losses as well as robustness were taken as objective functions; the model of optimization scheduling of approach and departure flights was established. Finally, the genetic algorithm was introduced to solve the model. The results showed that, in the program whose advance is not counted as a loss, its runway throughput is improved by 18.4%, the delay losses are reduced by 85.8%, and the robustness is increased by 20% compared with the results of FCFS (first come first served) algorithm, while, compared with the program whose advance is counted as a loss, the runway throughput is improved by 15.16%, flight delay losses are decreased by 75.64%, and the robustness is also increased by 20%. The algorithm can improve the efficiency and reduce delay losses effectively and reduce the workload of controllers, thereby improving economic results.
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Karcher, Claude, and Martin Buchheit. "Shooting Performance and Fly Time in Highly Trained Wing Handball Players: Not Everything Is as It Seems." International Journal of Sports Physiology and Performance 12, no. 3 (March 2017): 322–28. http://dx.doi.org/10.1123/ijspp.2016-0055.
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Purpose:To (1) assess the usefulness of countermovement jump (CMJ) testing to predict handball-specific jumping ability and (2) examine the acute effect of transiently modified jumping ability (ie, flight time) on shooting efficiency in wing players.Methods:Eleven young highly trained wing players performed 3 CMJs and 10 typical wing jump shots with 3 different modalities: without any constraint (CONTROL), while stepping on a 14-cm step (STEP), and wearing a weighted vest (VEST, 5% of body mass). Flight time and the associated scoring efficiency during the jump shots were recorded.Results:There was no clear correlation between jump shot and CMJ flight time, irrespective of the condition (r = .04–.18). During jump shots, flight time was most likely longer (effect size [ES] = 1.42–1.97) with VEST (635.4 ± 31 ms) and STEP (615.3 ± 32.9 ms) than CONTROL (566 ± 30.5 ms) and very likely longer with VEST than with STEP (ES = 0.6). The correlation between scoring efficiency and jump-shot flight time was not substantial either in each modality or for all shots pooled. The difference in scoring efficiency between the 3 jumps with the longest vs shortest flight times was either small (VEST, 48% vs 42%) or nonsubstantial (2 other conditions).Conclusions:The use of CMJ as a predictor of handball-specific jumping ability is questioned given the dissociation between CMJ and jump-shot flying time. These results also show that transiently affected flight time may not affect scoring efficiency, which questions the importance of jumping ability for success in wing players.
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Lehmann, F.-O. "Robofly reveals high muscle efficiency in insect flight muscle." Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 126 (July 2000): 90. http://dx.doi.org/10.1016/s1095-6433(00)80178-6.
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Lee, Dae-Yong, and Ja-Young Kang. "Measurement of Multi Conflict Avoidance for Free flight Efficiency." Journal of Korea Navigation Institute 16, no. 2 (April 30, 2012): 197–203. http://dx.doi.org/10.12673/jkoni.2012.16.2.197.
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Kwon, Min Seok, Chan Il Yoon, and Jiyong Kim. "Optimized Air Force Flight Scheduling Considering Pilot’s Mission Efficiency." Journal of Society of Korea Industrial and Systems Engineering 43, no. 4 (December 30, 2020): 116–22. http://dx.doi.org/10.11627/jkise.2020.43.4.116.
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Tian, Yong, Dawei Xing, Lili Wan, and Bojia Ye. "Study on the Optimization Method of Point Merge Procedure Based on Benefit in the Terminal Area." Mathematical Problems in Engineering 2020 (April 6, 2020): 1–12. http://dx.doi.org/10.1155/2020/5757948.
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With the rapid development of the air transport industry, the problem of airspace congestion and flight delay in the terminal area (TMA) becomes more and more serious. In order to improve the efficiency of flight operations in TMA, point merge procedure had been devised. This paper takes the approach routes in TMA as the research object, taking into account such conditions as obstacle clearance, flight interval, and procedure area. Based on the flight time, fuel consumption, pollutant emission, and noise impact, an optimization model of point merge procedure is constructed. Genetic algorithm is used to optimize the structure of procedure. The Shanghai Hongqiao International Airport is selected for simulation verification, and the actual flow distribution of the airport is analyzed as an example. The results show that the average flight time was reduced by 0.26 min, the average fuel consumption was reduced by 1,240.64 kg, the average NOx emissions were reduced by 1.09 kg, and the noise impact range was contracted by 55 km2 after optimization. The point merge procedure optimization method can be expected to reduce the flight time, fuel consumption, and environmental impact of flights in TMA, so as to optimize the aircraft approach trajectory.
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Billingsley, Ethan, Mehdi Ghommem, Rui Vasconcellos, and Abdessattar Abdelkefi. "Role of Active Morphing in the Aerodynamic Performance of Flapping Wings in Formation Flight." Drones 5, no. 3 (September 6, 2021): 90. http://dx.doi.org/10.3390/drones5030090.
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Migratory birds have the ability to save energy during flight by arranging themselves in a V-formation. This arrangement enables an increase in the overall efficiency of the group because the wake vortices shed by each of the birds provide additional lift and thrust to every member. Therefore, the aerodynamic advantages of such a flight arrangement can be exploited in the design process of micro air vehicles. One significant difference when comparing the anatomy of birds to the design of most micro air vehicles is that bird wings are not completely rigid. Birds have the ability to actively morph their wings during the flapping cycle. Given these aspects of avian flight, the objective of this work is to incorporate active bending and torsion into multiple pairs of flapping wings arranged in a V-formation and to investigate their aerodynamic behavior using the unsteady vortex lattice method. To do so, the first two bending and torsional mode shapes of a cantilever beam are considered and the aerodynamic characteristics of morphed wings for a range of V-formation angles, while changing the group size in order to determine the optimal configuration that results in maximum propulsive efficiency, are examined. The aerodynamic simulator incorporating the prescribed morphing is qualitatively verified using experimental data taken from trained kestrel flights. The simulation results demonstrate that coupled bending and twisting of the first mode shape yields the highest propulsive efficiency over a range of formation angles. Furthermore, the optimal configuration in terms of propulsive efficiency is found to be a five-body V-formation incorporating coupled bending and twisting of the first mode at a formation angle of 140 degrees. These results indicate the potential improvement in the aerodynamic performance of the formation flight when introducing active morphing and bioinspiration.
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Panteleymonov, I. N., A. Y. Potyupkin, V. M. Trankov, A. V. Panteleymonova, V. V. Filatov, and V. V. Todurkin. "Methods of Calculation of Performance Indicators of Spacecraft Flight Control Systems." Proceedings of Higher Educational Institutions. Маchine Building, no. 11 (716) (November 2019): 55–65. http://dx.doi.org/10.18698/0536-1044-2019-11-55-65.
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The article examines the problem of developing methods for evaluation of the effectiveness of space systems in flight. The criteria of spacecraft control efficiency are introduced, justified and calculated on examples. The accessibility and operational efficiency of on-board instrumentation, labour costs associated with the preparation and execution of communication and control sessions as well as reliability of communication systems are set as the main criteria of efficiency. As an example, the criteria of efficiency of space systems controlled with and without relay satellites are calculated. A comparative analysis of various approaches to the realization of space system in-flight control is performed. The developed methods can be used as a tool to evaluate the efficiency of space system in-flight control.
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Wakeling, JM, and CP Ellington. "Dragonfly flight. III. Lift and power requirements." Journal of Experimental Biology 200, no. 3 (February 1, 1997): 583–600. http://dx.doi.org/10.1242/jeb.200.3.583.
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A mean lift coefficient quasi-steady analysis has been applied to the free flight of the dragonfly Sympetrum sanguineum and the damselfly Calopteryx splendens. The analysis accommodated the yaw and accelerations involved in free flight. For any given velocity or resultant aerodynamic force (thrust), the damselfly mean lift coefficient was higher than that for the dragonfly because of its clap and fling. For both species, the maximum mean lift coefficient L was higher than the steady CL,max. Both species aligned their strokes planes to be nearly normal to the thrust, a strategy that reduces the L required for flight and which is different from the previously published hovering and slow dragonfly flights with stroke planes steeply inclined to the horizontal. Owing to the relatively low costs of accelerating the wing, the aerodynamic power required for flight represents the mechanical power output from the muscles. The maximum muscle mass-specific power was estimated at 156 and 166 W kg-1 for S. sanguineum and C. splendens, respectively. Measurements of heat production immediately after flight resulted in mechanical efficiency estimates of 13 % and 9 % for S. sanguineum and C. splendens muscles, respectively.
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Rogalla, Svana, Liliana D'Alba, Ann Verdoodt, and Matthew D. Shawkey. "Hot wings: thermal impacts of wing coloration on surface temperature during bird flight." Journal of The Royal Society Interface 16, no. 156 (July 2019): 20190032. http://dx.doi.org/10.1098/rsif.2019.0032.
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Recent studies on bird flight propose that hotter wing surfaces reduce skin friction drag, thereby improving flight efficiency (lift-to-drag ratio). Darker wings may in turn heat up faster under solar radiation than lighter wings. We used three methods to test the impact of colour on wing surface temperature. First, we modelled surface temperature based on reflectance measurements. Second, we used thermal imaging on live ospreys ( Pandion haliaetus ) to examine surface temperature changes with increasing solar irradiance. Third, we experimentally heated differently coloured wings in a wind tunnel and measured wing surface temperature at realistic flight speeds. Even under simulated flight conditions, darker wings consistently became hotter than pale wings. In white wings with black tips, the temperature differential produced convective currents towards the darker wing tips that could lead to an increase in lift. Additionally, a temperature differential between wing-spanning warm muscles and colder flight feathers could delay the flow separation above the wing, increasing flight efficiency. Together, these results suggest that wing coloration and muscle temperature both play important roles in modulating wing surface temperature and therefore potentially flight efficiency.
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Farrahi, Assal, and Ángel Sanz-Andrés. "Efficiency of Hysteresis Rods in Small Spacecraft Attitude Stabilization." Scientific World Journal 2013 (2013): 1–17. http://dx.doi.org/10.1155/2013/459573.
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A semiempirical method for predicting the damping efficiency of hysteresis rods on-board small satellites is presented. It is based on the evaluation of dissipating energy variation of different ferromagnetic materials for two different rod shapes: thin film and circular cross-section rods, as a function of their elongation. Based on this formulation, an optimum design considering the size of hysteresis rods, their cross section shape, and layout has been proposed. Finally, the formulation developed was applied to the case of four existing small satellites, whose corresponding in-flight data are published. A good agreement between the estimated rotational speed decay time and the in-flight data has been observed.
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Donateo, Teresa, and Roberto Totaro. "Hybridization of training aircraft with real world flight profiles." Aircraft Engineering and Aerospace Technology 91, no. 2 (February 4, 2019): 353–65. http://dx.doi.org/10.1108/aeat-01-2018-0036.
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Purpose The purpose of this paper is to analyze real-world flight data of a piston engine training aircraft collected from an internet-based radar service, along with wind data provided by a weather forecast model, and to use such data to design a hybrid electric power system. Design/methodology/approach The modeling strategy starts from the power demand imposed by a real-world wind-corrected flight profile, where speed and altitude are provided as functions of time, and goes through the calculation of the efficiency of the powertrain components when they meet such demand. Each component of the power system and, in particular, the engine and the propeller, is simulated as a black box with an efficiency depending on the actual working conditions. In the case of hybrid electric power system, the battery charging and discharging processes are simulated with the Shepherd model. Findings The variability of power demand and fuel consumption for a training aircraft is analyzed by applying the proposed methodology to the Piper PA-28-180 Cherokee, a very popular aircraft used for flight training, air taxi and personal use. The potentiality of hybridization is assessed by analyzing the usage of the engine over more than 90 flights. A tentative sizing of a hybrid electric power system is also proposed. It guarantees a fuel saving of about 5%. Originality/value The scientific contribution and the novelty of the investigation are related to the modeling methodology, which takes into account real-world flight conditions, and the application of hybridization to a training aircraft.
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Hwang, Myeong-hwan, Hyun-Rok Cha, and Sung Yong Jung. "Practical Endurance Estimation for Minimizing Energy Consumption of Multirotor Unmanned Aerial Vehicles." Energies 11, no. 9 (August 24, 2018): 2221. http://dx.doi.org/10.3390/en11092221.
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The practically applicable endurance estimation method for multirotor unmanned aerial vehicles (UAVs) using a battery as a power source is proposed. The method considers both hovering and steady-level flights. The endurance, thrust, efficiency, and battery discharge are determined with generally available data from the manufacturer. The effects of the drag coefficient related to vehicle shape and payload weight are examined at various forward flight speeds. As the drag coefficient increases, the optimum speed at the minimum required power and the maximum endurance are reduced. However, the payload weight causes an opposite effect, and the optimal flying speed increases with an increase in the payload weight. For more practical applications for common users, the value of S × Cd is determined from a preliminary flight test. Given this value, the endurance is numerically estimated and validated with the measured flight time. The proposed method can successfully estimate the flight time with an average error of 2.3%. This method would be useful for designers who plan various missions and select UAVs.
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Nahlinder, Staffan, Peter Berggren, and Bjorn Persson. "Increasing Training Efficiency Using Embedded Pedagogical Tools in a Combat Flight Simulator." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 49, no. 25 (September 2005): 2197–200. http://dx.doi.org/10.1177/154193120504902517.
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Many flight simulators today are made to provide a realistic environment for training. However, they often lack the possibility of providing pedagogical feedback to the person in training as well as feedback to any instructor leading the training. The purpose of this paper was to evaluate the usefulness of several pedagogical tools embedded in a flight simulator and to examine their potential for increasing training efficiency. Twenty students and instructors from the Swedish Air Force Flying Training School volunteered in this study. Seven embedded pedagogical tools were assessed using questionnaires. There was a quite consistent opinion in favor of the pedagogical tools implying that the embedded pedagogical tools is the way forward in training simulator development. The results from the present study are believed to be equally valid in many other areas besides flight simulators.
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Huang, Guoping, Eiman B. Saheby, and Anthony Hays. "Propulsive Efficiency of Ridge/Inlet Configuration." International Journal of Aerospace Engineering 2018 (August 19, 2018): 1–17. http://dx.doi.org/10.1155/2018/7462024.
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Controlling and directing the boundary layer on the surfaces of a flight vehicle are two of the most demanding challenges in advanced aerodynamic designs. The design of highly integrated and submerged inlets with a large offset between the entrance and compressor face is particularly challenging because of the need for controlling or reducing the adverse effects of the boundary layer on propulsive efficiency. S-duct diffusers are used widely in flight vehicles when the compressor face needs to be hidden, and their performance is generally sensitive to the quality of ingested boundary layer from the fuselage. Passive or active flow control mechanisms are needed to prevent flow separations at the bends. In this paper, a new method is presented for optimal inlet/body integration based on a pair of ridges ahead of the inlet and its effects on the performance of a semicircular S-duct inlet integrated on a flat surface using CFD. In this design, the ridge changes an inefficient inlet concept to one with acceptable performance. The new method of integration is practicable for top-mounted inlet configurations where the use of diverters and other mechanisms results in higher amounts of drag, weight, and complexity.