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Fuel flow analysis for the cruise phase of commercial aircraft on domestic routes
Abstract
From the point of view of the environmental impact of aviation, rather than fundamental strategies mainly intended for lower fuel consumption, and thereby less carbon dioxide emissions, more comprehensive approaches have emerged as climate optimized flight concepts, which promise potentially better strategies due to consideration of the tradeoff elements in a broader sense. Since climate optimized flight concepts introduce dynamic flight parameters for the best tradeoffs between economic and environmental indicators, defining the effect of these parameters on fuel consumption becomes ever more crucial. In this context, this study develops empirical equations for the cruise phase fuel flow which could be used to better understand fuel consumption. Major domestic routes in Turkey and the most frequently used narrow body commercial aircraft are investigated. The empirical equations are generated using actual flight data of 3857 flights (4320 cruise observations) performed by A319/320/321 and B737/B738 in Turkish air space. All of the flight data are obtained from the national flag carrier airline of Turkey, Turkish Airlines. According to the results, the effects of three main performance parameters, cruise altitude, mass and speed on the fuel flow, are characterized. The results show the amount of inefficient fuel usage through the carriage of unnecessary mass, departing from the optimum cruise altitude or expediting cruise flight.
... The article discusses the fuel consumption and fuel price ratio in different flight stages and wind components. Similar articles in a journal [1], [2] discuss the fuel flow and consumption too, limited for just cruising but not including the actual price for the year 2023 and for other flight phases. ...
... Similar topics also appear in Scopus and Web of Science journals too, like [1], [2]. In [2] the authors focus on the fuel flow only in the cruise phase. ...
... Similar topics also appear in Scopus and Web of Science journals too, like [1], [2]. In [2] the authors focus on the fuel flow only in the cruise phase. The other articles with similar issues are mentioned in the part of Introduction. ...
The article deals with the wind component and fuel consumption and pricing differences. The article contains two main chapters - theoretical (general knowledge) and practical (simulated models - in different flight stages based on the dates from the AFM manual of the C560 XLS+ A/C type). The discussion evaluates the upcoming data and shows how the fuel price can change. The article's topic concerns meteorology, A/C type performance, and economy. Every part of the mentioned topic is important for a safe, fluent, and economical flight.
... [11,12]. Another study within T Some of these are described in the next paragraphs urkish airspace suggested that aircraft might be flying with unnecessary mass due to loading of too much fuel for the given flight [13]. In order to minimize the flight cost, the flight fuel and time requirements to execute a given mission need to be optimized. ...
... The selected waypoint can only be placed between the reference waypoint neighbor trajectory position and the position of the waypoint from the trajectory being mutated. The lateral mutation is computed with Eq. (13). (13) where Lateral Mutation W provides the new waypoint location, Position W is the initial waypoint position, Position N is the neighbor waypoint position, random is a random value between (-1...1), and step is the step of the grid for the selected dimension. ...
... The lateral mutation is computed with Eq. (13). (13) where Lateral Mutation W provides the new waypoint location, Position W is the initial waypoint position, Position N is the neighbor waypoint position, random is a random value between (-1...1), and step is the step of the grid for the selected dimension. ...
Fuel burn releases polluting particles to the atmosphere. Aeronautical operations have been estimated as being responsible for 2% of the total amount of carbon dioxide liberated to the atmosphere each year. Fuel is also one of the major expenses for airlines. Reducing the amount of fuel required to power flights brings benefits to both the environmental and economic aspects of the aeronautical industry. This paper aims to develop a new optimization algorithm that computes fuel-efficient aircraft reference trajectories inspired by the artificial bee’s colony and based on a numerical performance model. The flight trajectory is optimized in terms of speeds, altitudes, and geographical positions, while respecting the required time of arrival constraint. The optimal trajectory is composed of waypoints placed in each of the available dimensions (coordinates, altitudes, and speeds). Winds and temperatures are taken into account. These trajectories will be improved by taking all of the dimensions into consideration simultaneously, instead of improving them one after the other. Results have shown that, when flying under the free-flight concept and fulfilling the required time of arrival constraint, the algorithm saved around 5% of the fuel burn with respect to as-flown flights.
... Aircraft and engine improvements/new engine technology (Macintosh and Wallace, 2009) The improvement of engine depends on the upgrading of technology, so as to reduce emissions Communication navigation and surveillance (Williams, 2007) Technological upgrading of communication and navigation helps optimize air traffic efficiency Energy utilization technology (Huang et al., 2019) Energy efficient utilization technology reduces energy consumption Renewable fuel conversion technology (de Jong et al., 2015) The transformation of renewable fuels depends on technological upgrading Sliding mode (Stettler et al., 2011) Technical improvement of taxi mode to reduce energy consumption in aviation industry Technical feasibility (Dodd et al., 2018) Obstacles to technological upgrading Technical uncertainty (Dodd et al., 2018) Obstacles to technological upgrading The fuselage technology (Hileman et al., 2013) Fuselage improvement technology to achieve efficient operation and reduce energy consumption The intensity of the fuel (Zhou et al., 2016) Technological upgrading can improve energy intensity and achieve emission reduction Fleet renewal rate (Lee et al., 2009) Technology upgrade leads to fuselage update (Lo et al., 2020) The implementation of emission reduction policies can stimulate the demand and production of the aviation industry, and can also reduce the growth of air travel by increasing ticket prices. Carbon price mechanism/carbon pricing (Hasan et al., 2021) Policy discontinuity (Chao et al., 2019) CORSIA's policy (Dodd et al., 2018) Environment Environmental impact (Koudis et al., 2017) The flight environment will affect the flight efficiency of aircraft Terrain and climate (Li et al., 2019) The runway characteristics (Koudis et al., 2017) Weather condition (Turgut et al., 2014) Meteorological services (Williams, 2007) Parameter Altitude/cruising altitude/optimum cruising altitude (Wilkerson et al., 2010) Aircraft climb height adjustment can effectively reduce fuel consumption Thrust (Stettler et al., 2011) The aircraft will affect emissions in the process of overcoming resistance Flight speed (Turgut et al., 2014) The economic speed is the most fuel-efficient Table B.6 Summary of influencing factors. ...
... Aircraft and engine improvements/new engine technology (Macintosh and Wallace, 2009) The improvement of engine depends on the upgrading of technology, so as to reduce emissions Communication navigation and surveillance (Williams, 2007) Technological upgrading of communication and navigation helps optimize air traffic efficiency Energy utilization technology (Huang et al., 2019) Energy efficient utilization technology reduces energy consumption Renewable fuel conversion technology (de Jong et al., 2015) The transformation of renewable fuels depends on technological upgrading Sliding mode (Stettler et al., 2011) Technical improvement of taxi mode to reduce energy consumption in aviation industry Technical feasibility (Dodd et al., 2018) Obstacles to technological upgrading Technical uncertainty (Dodd et al., 2018) Obstacles to technological upgrading The fuselage technology (Hileman et al., 2013) Fuselage improvement technology to achieve efficient operation and reduce energy consumption The intensity of the fuel (Zhou et al., 2016) Technological upgrading can improve energy intensity and achieve emission reduction Fleet renewal rate (Lee et al., 2009) Technology upgrade leads to fuselage update (Lo et al., 2020) The implementation of emission reduction policies can stimulate the demand and production of the aviation industry, and can also reduce the growth of air travel by increasing ticket prices. Carbon price mechanism/carbon pricing (Hasan et al., 2021) Policy discontinuity (Chao et al., 2019) CORSIA's policy (Dodd et al., 2018) Environment Environmental impact (Koudis et al., 2017) The flight environment will affect the flight efficiency of aircraft Terrain and climate (Li et al., 2019) The runway characteristics (Koudis et al., 2017) Weather condition (Turgut et al., 2014) Meteorological services (Williams, 2007) Parameter Altitude/cruising altitude/optimum cruising altitude (Wilkerson et al., 2010) Aircraft climb height adjustment can effectively reduce fuel consumption Thrust (Stettler et al., 2011) The aircraft will affect emissions in the process of overcoming resistance Flight speed (Turgut et al., 2014) The economic speed is the most fuel-efficient Table B.6 Summary of influencing factors. ...
The international aviation industry is one of the fastest growing industries, resulting in an increase of greenhouse gas emissions. Controlling aviation carbon emissions is needed to further prevent future climate change as the demand for aviation continues to expand. Effective ways should be taken to control aviation carbon emissions, namely identifying the set of driving factors behind the carbon emissions, as well as, exploring low-carbon technologies in aviation. However, few studies have systematically identified the driving factors and given a timeline list of aviation low-carbon technologies. Therefore, from the life cycle perspective (including the aircraft designing, operating, and recovery), this paper applies text mining and literature metrology to identify the driving factors systematically. Moreover, an evaluation model is established to present the prioritization of factors, and the Delphi method is applied to create a timeline list of the low-carbon technologies in the aviation industry. The results show that demand, technological improvement, and alternative fuels are the most important factors affecting carbon emissions in the aviation industry, with their contribution percentages of 16 %, 14 %, and 12 %, respectively. In the short term, aviation relies more on policies to reduce emissions (supported by 79 % of experts). In the long term, technological progress enables the production of increasingly mature alternative fuels as well as reduces production costs. Among the set of experts, 74 % support strategies relating to renewable fuel and low carbon technologies as the main factors for the aviation industry to reduce carbon emissions.
... In addition, previous studies have been carried out with the objective of analyzing the aircraft's fuel consumption during the different flight phases by means of energy balance methods [5,6] (pp. [11][12][13][14][15], or statistical models [7][8][9][10][11][12][13]. Other recent studies such as [14][15][16] propose some frameworks in which aircraft performance models (which are based on some of the abovementioned softwares), fleet data sets and route data sets are integrated into unique tools where statistical techniques such as regression analysis are applied in order to estimate fuel consumption and emissions during the different flight phases and at a global scale. In addition, aircraft emission inventories have been developed throughout the years based on historical fuel burn data [17][18][19] or on other methodologies [20] and enhanced by a more accurate estimation of the pollutant emission indices [21]. ...
... In addition, previous studies have been carried out with the objective of analyzing the aircraft's fuel consumption during the different flight phases by means of energy balance methods [5,6] (pp. [11][12][13][14][15], or statistical models [7][8][9][10][11][12][13]. Other recent studies such as [14][15][16] propose some frameworks in which aircraft performance models (which are based on some of the abovementioned softwares), fleet data sets and route data sets are integrated into unique tools where statistical techniques such as regression analysis are applied in order to estimate fuel consumption and emissions during the different flight phases and at a global scale. ...
In this paper we propose a mathematical model for the fuel consumption analysis during aircraft cruise. A closed-form formula that expresses the aircraft’s weight variation over time, and hence, the fuel flow rate, is obtained as a result. Furthermore, a closed-form expression of the aircraft’s main performance parameters is also obtained. We compare the values of such parameters computed by using the Piano-X software and computed by using our mathematical model. Simulation results confirm that our mathematical model provides results very close to reality. Finally, the closed-form formula of the fuel flow rate provided by our model is used to improve the calculation of the carbon dioxide emissions for four example routes, which, unlike here, are usually obtained under the assumption of a constant value of the fuel flow rate.
... In order to provide a solution for this, numerical design optimizations, as suggested by Henderson et al [3] can be undertaken to explore different parameters which can ultimately lead to lesser fuel consumption. Turgut et al [4] also note the redundant fuel utilization that arises due to unnecessary mass considerations. One option is to minimize the overall weight of the aircraft. ...
... The Bayesian algorithm can quickly find the airfoil shape with the best aerodynamic performance for the NACA four-digit airfoils. The camber of the airfoil is the most basic factor that affects the lift because the change in the size and position of the camber could have a great influence on the aerodynamic characteristics of an airfoil [41]. Airfoils can meet different flight conditions such as take-off, cruise, and landing by changing its camber. ...
This paper proposes a novel aerodynamic optimization framework for airfoils, which utilizes OpenFOAM, an open-source computational fluid dynamics software, and a Bayesian network to achieve efficient optimization of airfoil aerodynamic performance. Aerodynamic analysis of the NACA 4-digit airfoil was performed by adopting the Spalart-Allmaras turbulence model to solve the Reynolds-averaged Navier—Stokes equations. With the use of this framework, the optimal lift-to-drag ratio can be found by using a small number of objective evaluations. The optimal angle of attack and aerodynamic shape can be obtained under different thicknesses. Finally, after various aerodynamic objectives are arranged and combined, the Pareto fronts were obtained by the multi-objective Bayesian algorithm. Compared with the original NACA four-digit airfoil, the lift-to-drag ratio of the airfoil after single-objective optimization is greatly improved as the thickness increases, and the airfoil after multi-objective optimization achieves different Pareto sets according to different sailing phases.
... Design of airframe and engine can increase the flight efficiency, while it decreases with bad air traffic management and high fuel price. Also, the fuel efficiency is affected by the emission rates, air traffic, speed, engine weight, and flight altitude (Turgut et al. 2014;Aygun and Turan 2021;Caglayan and Caliskan 2019). ...
In this paper, environmental impact analysis is applied to the various auxiliary power units (APUs) used for commercial aircraft in air transportation sector. The exhaust emissions of different auxiliary power units used in commercial aircraft are investigated. The emission index (EI), global warming potential (GWP) rate, global warming potential index (GWPI), environmental impact (EnI) rate, environmental impact index (EnII), environmental damage cost (EDC) rate, and environmental damage cost index (EDCI) of the exhaust emissions of APUs are computed. The GTCP36-300 model APU has the lowest total emission rate (TER) with 1.333 kg/h, the GTC85-129 model APU has the maximum total environmental index (TEI) by 24.719 g/kg-fuel, the GTCP36-300 model APU has the best total global warming potential value with 2709.176 kg/h CO2_eqv, the TSCP700 model APU has the worst global warming potential index rate as 52.481 kg/kWh CO2_eqv, the best total environmental damage cost rate is calculated to be 3.717 €/h for GTC85-72 model APU, the TSCP700 model APU has the highest environmental damage cost index with 0.130 €/kWh, the maximum total environmental impact is computed to be 5656.378 mPts/h for GTCP660 model APU, and the best total environmental impact index is determined for the GTC85-72 model APU.
... The cruise is the longest part of the flight. Ardema andAsuncion (2009), Fan et al. (2020), Jensen et al. (2015), and Turgut et al. (2014) present cruise-flight optimization studies to reduce the fuel consumption of commercial aircraft. Ardema and Asuncion (2009) compared the results of a singular optimal control problem and the Brequet range equation (for constant altitude and velocity). ...
This paper presents a comparison of fuel-optimal and shortest paths of an unmanned combat aerial vehicle (UCAV) with obstacle avoidance. A nonlinear constrained optimization algorithm is applied to obtain the optimal paths. An initial value problem (IVP) and an inverse-dynamics approach are used separately to determine optimal paths for various scenarios and in order to reduce computation time. While inputs of the optimization algorithm are discrete control variables in the IVP method, discrete state variables are used as inputs in the inverse-dynamics method. The minimized path segments of the geometrical model provide an initial estimation of the heading angle for the aircraft flight mechanics model. The number of variables used by the optimization algorithm has a direct effect upon the optimal accuracy; however, the computation time is inversely proportional to the number of the variables. Simulation results demonstrate that the proposed IVP method effectively converges to optimal solutions.
... Kesgin et al. [26] estimated the aircraft pollutant emissions of 40 Turkish airports during the landing and take-off (LTO) cycle. Turgut et al. [27] established the fuel flow rate empirical equations during the cruise phase to research the aircrafts fuel consumption in the changing situation. Bo et al. [28] estimated the aviation emissions of all civil airports in mainland China and analyzed the atmospheric environmental impact of pollutants on the airport. ...
Under the background of economic globalization, the air transport industry developed rapidly. It turns out that the city-to-city network has not been able to adapt well to the development of the society, and the hub-and-spoke network came into being. The hub-and-spoke network demonstrates the advantages of reducing the operating costs of airlines to keep a competitive advantage, and by maintaining the interests of airlines in the rapidly developing context. However, during the operation of aircrafts, they consume fuel and spew a great deal of harmful pollutants into the air, which has an adverse impact on the living environment. This paper explores the impact and external costs associated with hub-and-spoke network in air transport from an environmental perspective. With some mathematical models, we construct a hub-and-spoke network and take a quantitative study on the environmental impact of air transport. For calculating pollutant emissions, meteorological conditions were considered to revise the pollutant emission factors of the Engine Emissions Data Base (EEDB) published by International Civil Aviation Organization (ICAO). The environmental external costs measurement model is employed to calculate the externality of toxic gas and greenhouse gas (GHG). In order to make the study more convincing, two alternative networks are computed: hub-and-spoke network and city-to-city network. It is found that the hub-and-spoke network is associated with poorer environmental impact and environmental external costs because of the different network characteristics and the scale of the fleets. Therefore, under the general trend of green aviation, the environmental impact and environmental external costs associated with hub-and-spoke network in air transport provides a certain reference for airlines’ strategic decision-making.
... Later studies based on that work proved that commercial flights over the continental United States and inter-continental commercial flights do not take place at their optimal altitudes and speeds [17][18][19]. Another study indicated that domestic flights within Turkish airspace loaded unnecessary weight, which led to an increase of fuel flow and thus added to the fuel consumption [20]. These studies served to highlight the need to develop trajectory optimization algorithms to reduce fuel consumption. ...
Aircrafts require a large amount of fuel in order to generate enough power to perform a flight. That consumption causes the emission of polluting particles such as carbon dioxide, which is implicated in global warming. This paper proposes an algorithm which can provide the 3D reference trajectory that minimizes the flight costs and the fuel consumption. The proposed algorithm was conceived using the Floyd–Warshall methodology as a reference. Weather was taken into account by using forecasts provided by Weather Canada. The search space was modeled as a directional weighted graph. Fuel burn was computed using the Base of Aircraft DAta (BADA) model developed by Eurocontrol. The trajectories delivered by the developed algorithm were compared to long-haul flight plans computed by a European airliner and to as-flown trajectories obtained from Flightradar24®. The results reveal that up to 2000 kg of fuel can be reduced per flight, and flight time can be also reduced by up to 11 min.
... Flight operations might also reduce fuel consumption. According to different studies, in the continental United States airspace [4,5] and in the Turkish airspace [6] aircraft do not fly at their optimal speeds and altitudes. It is thus of interest to provide the aircraft with a more economical reference trajectory. ...
The increasing of flights around the world has led to various problems for the aeronautical industry such as saturated air space and higher levels of fossil fuel consumption. The way in which en-route flights are handled should be improved in order to increase airways’ capacity. A solution is to make aircraft to arrive at specific waypoints at a time constraint called Required Time of Arrival (RTA). Fossil fuel brings as a consequence the release of polluting particles to the atmosphere such as carbon dioxide and nitrogen oxides. It is thus desirable to compute the most economical trajectory in terms of fuel burn while fulfilling the RTA constraint. This article proposes a horizontal reference trajectory optimization algorithm based on the Particle Swarm Optimization technique in order to reduce fuel burn while fulfilling the RTA constraint. Results showed that for a flight without RTA constraint, up to 4% of fuel can be saved comparing against the trajectory of reference. The algorithm was normally able to meet the RTA constrain. However, aggressive RTA constraints might reduce the optimization levels of fuel compared with flights without RTA constraint.
... Analysis of many influence factors of fuel oil consumption. Scholars (Turgut et al.,2014;Brueckner and Abreu, 2017) determined that aircraft mass and speed during the flight process at cruising altitude were the main influence factors of fuel oil consumption; however, the modeling calculation of fuel oil consumption was not involved. Nikoleris et al. (2011) and Singh and Sharma (2015) classified and evaluated estimation methods for aircraft oil consumption from macroscopic aspects based on the estimation of total fuel oil consumption. ...
Accurate assessment of aircraft fuel consumption is an important means for airlines to reduce flight costs and control fuel emissions. By analyzing the actual flight data of QAR, the functional relationship between the aerodynamic parameters in the fuel consumption model of the departure climb phase is fitted, and the crosswind is added to the fuel consumption assessment model. Based on the analysis of the departure training of Qingdao Airport, the fuel consumption model of the exit climbing stage was calculated using the improved fuel consumption model. The results showed that the calculation accuracy of the wind tunnel experiment was improved by 3.6%, and the theory of the fuel evaluation experiment considering the crosswind was considered. The accuracy of the model calculation and QAR data is 93.3%.
... However, there are also operational improvements that can be implemented on every aircraft regardless of their generation, such as engine washing, assisted taxiing, reducing the Auxiliary Power Unit (APU) use and trajectory optimization [9]. This last option is especially promising as it has been established that aircraft do not fly at the speeds and altitudes that provide the most economical trajectory in terms of fuel burn [10][11][12][13]. By providing efficient trajectories, the amount of fuel needed to fly the required distance is reduced, thereby reducing the pollution released to the atmosphere. ...
Aircraft require significant quantities of fuel in order to generate the power required to sustain a flight. Burning this fuel causes the release of polluting particles to the atmosphere and constitutes a direct cost attributed to fuel consumption. The optimization of various aircraft operations in different flight phases such as cruise and descent, as well as terminal area movements, have been identified as a way to reduce fuel requirements, thus reducing pollution. The goal of this chapter is to briefly explain and apply different metaheuristic optimization algorithms to improve the cruise flight phase cost in terms of fuel burn. Another goal is to present an overview of the most popular commercial aircraft models. The algorithms implemented for different optimization strategies are genetic algorithms, the artificial bee colony, and the ant colony algorithm. The fuel burn aircraft model used here is in the form of a Performance Database. A methodology to create this model using a Level D aircraft research flight simulator is briefly explained. Weather plays an important role in flight optimization, and so this work explains a method for incorporating open source weather. The results obtained for the optimization algorithms show that every optimization algorithm was able to reduce the flight consumption, thereby reducing the pollution emissions and contributing to airlines’ profit margins.
... Analysis of influence factors of fuel consumption. Turgut et al. [8] and Brueckner and Abreu [9] determined that aircraft mass and speed during the cruising phase are the main influence factors of fuel consumption; their studies developed empirical equations for the cruise phase fuel flow on the basis of actual flight data of five aircraft models, but did not provide the modeling calculation of fuel consumption during the departure climbing phase. Bartel and Young [10] established a model of fuel consumption for turbofan jet aircraft; however, the model was not used to study the influences of changes in meteorological environments, such as the atmospheric density, temperature, and pressure at different altitudes, on fuel consumption. ...
Accurate estimation of the fuel consumed during aircraft operation is key for determining the fuel load, reducing the airline operating cost, and mitigating environmental impacts. Aerodynamic parameters in current fuel consumption models are obtained from a static diagram extracted from the outcomes of wind tunnel experiments. Given that these experiments are performed in a lab setting, the parameters cannot be used to estimate additional fuel consumption caused by aircraft performance degradation. In addition, wind tunnel experiment results rarely involve the influence of crosswind on fuel consumption; thus, the results could be inaccurate when compared with field data. This study focuses on the departure climbing phase of aircraft operation and proposes a new fuel consumption model. In this model, the relationships between aerodynamic parameters are extracted by fitting quick access recorder (QAR) actual flight data, and the crosswind effect is also considered. Taking QAR data from two airports in China, the accuracy of the proposed model and its transferability are demonstrated. Applying the proposed model, the fuel saving of a continuous climb operation (CCO) compared with the traditional climb operation is further quantified. Finally, how aircraft mass, climbing angle, and different aircraft models could affect the fuel consumption of the climbing phase of aircraft operation is investigated. The proposed fuel consumption model fills gaps in the existing literature, and the method can be used for developing specific fuel consumption models for more aircraft types at other airports.
... Ryerson and Kim (2014) studied the impact of airline merges on reducing fuel consumption and passenger service level degradation. Turgut et al. (2014) explored the effects of altitude, aircraft speed and aircraft weight on fuel consumption. They noted that 1 ton reduction in aircraft mass, 1000 ft increase in flight altitude, and 1 knot decrease in cruise speed lead to 15e21 kg, 26e28 kg, and 7.7e7.8 ...
The negative appraisals of the impact of airline industry on climate change have forced the industry to become greener. Over the past several decades, CO2 emissions in the airline industry have increased considerably, thereby adversely affecting the environment. Therefore, airlines are seeking different approaches to reduce the environmental degradation. In this paper, we study cruise speed control to achieve this goal by reducing CO2 emissions while studying passenger service level. We use some indicators to measure the passenger service level in the airline industry. These indicators create a conflict between CO2 emissions and passenger service level. We develop a bi-objective mixed-integer non-linear programming model to integrate flight scheduling, aircraft-path assignment, and gate assignment with the aim of reducing CO2 emissions while increasing passenger service level. Based on a real problem, the model can lead to 11% and 31% improvement in CO2 emissions and passenger service level, respectively. The model is NP-hard. Therefore, we develop a new constructive heuristic method, and we also use the multi-objective simulated annealing algorithm and extend this algorithm to enhance its performance. We also use the design of experiment and Taguchi method to optimize the algorithms parameters. Finally, we evaluate the proposed methods based on information retrieved from major U.S. airlines.
... Turgut et al. [38] studied the criteria affecting fuel consumption in the air transport. These criteria include cruise altitude, cruise flight time, aircraft speed and its mass. ...
In the past decade, fuel consumption and CO2 emission have increased in the airline industry. Large CO2 footprint has a damaging effect on the environment. Global concerns over this issue has made the airline industry to be greener. Most efforts of the green airline industry are improving the fuel consumption to reduce the CO2 emission and its environmental damage. Here, we use cruise speed control to control the fuel consumption and CO2 emission. Each aircraft has a different speed level needing a different fuel consumption. Service quality is studied besides the energy consumption. We investigate two objectives including total energy consumption (TEC) and passenger service level (PSL). TEC and PSL are conflicting in nature. We develop a mixed-integer nonlinear programming model to integrate schedule design, aircraft assignment and maintenance routing problems. We make use of the augmented ε-constraint method to solve the problem. To evaluate the model, a real data based on the Emirates airline flights is used. The results are compared using four different scenarios
... Jensen [15][16][17] suggested the possible gains to be made in improving flight reference trajectories, as many aircraft do not fly at their optimal speeds or altitudes. Another study on fuel flow in flights within Turkey also suggested that aircraft trajectories should be improved to reduce fuel consumption [18]. ...
This paper describes an optimization algorithm that provides an economical vertical navigation profile by finding the combinations of climb, cruise, and descent speeds, as well as altitudes, for an aircraft to minimize flight costs. The computational algorithm takes advantage of a space search reduction methodology to reduce the initial number of available speed and altitude combinations. The optimal solution was found by implementing the beam search algorithm. A bounding function that correctly estimates the flight cost by considering step climbs was developed to reduce the number of calculations required by the beam search algorithm. The full-flight fuel burn cost was obtained using a performance database-based method. The algorithm uses a numerical performance model instead of equations of motion to compute fuel burn. The database was developed by using flight experimental data. To validate the algorithm, its results were compared to those of three other algorithms: an exhaustive search, beam search, and search space reduction. The solution providedbythe algorithm was also compared tothe solution provided byaflight management system. Following this comparison, the algorithm systematically found the optimal solutions, which were better in terms of flight cost than those provided by the flight management system.
... In spite of the airlines' interest in reducing flight costs, regulations, traffic, and airline policies do not guarantee that aircraft fly at their optimal speed, altitudes, and trajectories [4][5][6][7]. This leads to unnecessary fuel burn which not only increases flight costs, but it adds to environmental degradation. ...
A methodology of aircraft reference trajectory optimization inspired by the ant colony optimization is used in this paper to find the most efficient trajectory in terms of fuel burn and flight cost during the cruise phase. Weather conditions are taken into account in computing the most economical trajectory. The algorithm is designed in two consecutive stages. First, the reference trajectory is optimized in three dimensions. Then, the most economical combination of Mach numbers that fulfills the required time of arrival constraint over that three-dimensional trajectory is found, creating a four-dimensional reference trajectory. Different simulation tests consisted of trajectories following a fixed altitude geodesic trajectory, as well as of real as-flown flights. Simulations revealed that the ant colony algorithm was able to find the most efficient trajectory and the flight cost was 6.82% more economical than the geodesic reference trajectory. Moreover, tests showed that the ant colony algorithm was able to find a four-dimensional trajectory close to the real flight plan trajectory, providing an optimization average of 0.91%. Studies showed that making a three-dimensional trajectory fulfilling the required time of arrival constraint led to an important loss of 2.4% of optimization due to the Mach number changes.
... This rapid expansion of air traffic and the concern for environmental consciousness has greatly encouraged academia and the aerospace industry to improve the overall efficiency of airline operations [3][4][5][6] . According to several studies, most of aircraft do not fly at their optimal trajectory in terms of altitude and speed [7][8][9] . In this context, optimizing the vertical flight profile could be a promising solution to both improve the management of the air traffic and the reduction of environmental emissions [10][11][12][13] . ...
... Other discussions have been conducted regarding the savings that flying at low cruise speeds may bring, as well as at how lower cruise speeds would affect other aircraft flying near the low-speed cruise aircraft 18,19 . Turgut et al. 20 developed equations to obtain the fuel flow for different aircrafts and found out that flight trajectories for national flight within Turkey can be improved. ...
With the objective of reducing the flight cost and the amount of polluting emissions released in the atmosphere, a new optimization algorithm considering the climb, cruise and descent phases is presented for the reference vertical flight trajectory. The selection of the reference vertical navigation speeds and altitudes was solved as a discrete combinatory problem by means of a graph-tree passing through nodes using the beam search optimization technique. To achieve a compromise between the execution time and the algorithm’s ability to find the global optimal solution, a heuristic methodology introducing a parameter called “optimism coefficient was used in order to estimate the trajectory’s flight cost at every node. The optimal trajectory cost obtained with the developed algorithm was compared with the cost of the optimal trajectory provided by a commercial flight management system(FMS). The global optimal solution was validated against an exhaustive search algorithm(ESA), other than the proposed algorithm. The developed algorithm takes into account weather effects, step climbs during cruise and air traffic management constraints such as constant altitude segments, constant cruise Mach, and a pre-defined reference lateral navigation route. The aircraft fuel burn was computed using a numerical performance model which was created and validated using flight test experimental data.
... BADA has been also used to model en-route aircraft performance in the context of projects that assessed the impact of operational mitigations on aircraft-related fuel burn and emissions (Lovegren and Hansman, 2011;Malwitz et al., 2007;Williams et al., 2002). Finally, BADA has been widely used to compute aircraft fuel burn when actual flight data records are available or a flight profile has been specified otherwise Pham et al., 2010;Sheng et al., 2015;Turgut et al., 2014;Williams and Noland, 2005). ...
In this paper, typical flight paths, fuel burn and carbon dioxide (CO2) emissions are computed using a rich data set and two estimation approaches: (i) a clustering and landmark registration technique and (ii) a method based on the EUROCONTROL’s Base of Aircraft Data (BADA) performance model. Clustering is employed to extract flight characteristics and organize altitude profiles accordingly. Our flight path and CO2 emissions analysis focuses on the Climb-Cruise-Descent (CCD) cycle, since different operational conditions during the Landing and Take-off cycle may result in significant deviations in terms of fuel burn and CO2 emissions and different modeling assumptions and approaches should be adopted. The key features of the CCD cycle are the flight distance, the aircraft type and the flight direction. Path segmentation and landmark registration are employed for path representation and smoothening of discontinuities. The paths estimated by the above method are compared to those obtained by the point mass BADA model. Noticeable deviations in the resulting estimates of the operational characteristics are found. Higher deviations in prediction errors are found in the climb and descent duration and the rate of climb and descent. The typical altitude profiles obtained by the two methods are used to determine fuel burn and CO2 emissions. The difference in the resulting estimates are less stark; on a fleet-wide level the fuel burn of the relevant typical profiles differ by 7%. Emission maps of the U.S. airspace enabling the identification of critical emission spots including routes, airports, seasons and aircraft type are constructed.
... The TBO concept is important, as it will allow more aircraft to fly at their optimal speed and altitudes. According to (Jensen et al., 2014, Jensen et al., 2013, Jensen et al., 2015, Turgut et al., 2014, many aircraft do not fly at their optimal speed and altitudes. This could be due to a lack of planning by airlines or to ATM restrictions. ...
Cruise is normally the longest and most expensive phase in a long-haul flight. Taking advantage of winds to reduce flight time using a constant mach number is of real interest to the aeronautical industry. Reducing flight time will reduce time related costs, help passengers to catch their connections, and reduce fuel consumption. Saving fuel also leads to fewer polluting emissions released to the atmosphere. The “free-flight” concept is adopted here, with the search space area modeled as a graph in which the weather information at each vertex is obtained from predictions from Environment Canada. The Floyd-Warshall optimization algorithm was implemented to allow the flight reference trajectory optimization to have automatic decision making capacities to deliver the shortest path trajectory between departure and destination airports. Simulations showed that flight time savings as high as 19 minutes could be obtained, representing (roughly estimated) a savings of 1.2 tons of fuel.
... The TBO concept is important, as it will allow more aircraft to fly at their optimal speed and altitudes. According to (Jensen et al., 2014, Jensen et al., 2013, Jensen et al., 2015, Turgut et al., 2014, many aircraft do not fly at their optimal speed and altitudes. This could be due to a lack of planning by airlines or to ATM restrictions. ...
Cruise is normally the longest and most expensive phase in a long-haul flight. Taking advantage of winds to reduce flight time using a constant mach number is of real interest to the aeronautical industry. Reducing flight time will reduce time related costs, help passengers to catch their connections, and reduce fuel consumption. Saving fuel also leads to fewer polluting emissions released to the atmosphere. The " free-flight " concept is adopted here, with the search space area modeled as a graph in which the weather information at each vertex is obtained from predictions from Environment Canada. The Floyd-Warshall optimization algorithm was implemented to allow the flight reference trajectory optimization to have automatic decision making capacities to deliver the shortest path trajectory between departure and destination airports. Simulations showed that flight time savings as high as 19 minutes could be obtained, representing (roughly estimated) a savings of 1.2 tons of fuel.
... Different studies concluded that aircraft do not fly at their optimal speeds and altitudes (Jensen et al., 2013, Jensen et al., 2014. Another study which analyzed the fuel flow for different flights in Turkey arrived to the conclusion that trajectories can be improved (Turgut et al., 2014). ...
Fuel required to power flights releases polluting particles such as carbon dioxide (CO 2) and Nitrogen Oxides (NOx). Reducing the fuel consumption to power a given flight brings as a consequence a reduction of the pollution released to the atmosphere and a reduction in flight costs. Trajectory optimization has been seen as an alternative to reduce fuel consumption by guiding aircraft to zones where they can have a better performance in terms of fuel consumption. In this paper, the Dijkstra's algorithm was implemented to identify the waypoints where to perform the change of altitudes to reduce the fuel consumption taking into account the aircraft performance and weather conditions. The aircraft performance was obtained from a numerical database obtained from experimental flight test data and the weather information was obtained from the forecast provided by Weather Canada. The deterministic Dijkstra's algorithm was selected because the methodology developed in this paper is aimed to be loaded in a Flight Management System. The search space was modeled as a graph in 2 dimensions: altitude and distance. Simulations results comparing different trajectories have shown savings of over 4.33 % in a flight such as Vancouver to Madrid.
... Different studies concluded that aircraft do not fly at their optimal speeds and altitudes (Jensen et al., 2013, Jensen et al., 2014). Another study which analyzed the fuel flow for different flights in Turkey arrived to the conclusion that trajectories can be improved (Turgut et al., 2014). Trajectories are normally computed on ground and delivered to the aircraft crew in a document called " flight plan " . ...
Fuel required to power flights releases polluting particles such as carbon dioxide (CO 2) and Nitrogen Oxides (NOx). Reducing the fuel consumption to power a given flight brings as a consequence a reduction of the pollution released to the atmosphere and a reduction in flight costs. Trajectory optimization has been seen as an alternative to reduce fuel consumption by guiding aircraft to zones where they can have a better performance in terms of fuel consumption. In this paper, the Dijkstra's algorithm was implemented to identify the waypoints where to perform the change of altitudes to reduce the fuel consumption taking into account the aircraft performance and weather conditions. The aircraft performance was obtained from a numerical database obtained from experimental flight test data and the weather information was obtained from the forecast provided by Weather Canada. The deterministic Dijkstra's algorithm was selected because the methodology developed in this paper is aimed to be loaded in a Flight Management System. The search space was modeled as a graph in 2 dimensions: altitude and distance. Simulations results comparing different trajectories have shown savings of over 4.33 % in a flight such as Vancouver to Madrid.
... Due to air traffic restrictions, or airlines polcies, aircraft normally do not fly at their optimal speeds, altitudes, as was observed by the studies performed in (Jensen et al., 2014, Jensen et al., 2013, Jensen et al., 2015, Turgut et al., 2014. Fight reference trajectory optimization represents an opportunity to reduce the polluting emissions released to the atmosphere and the flight cost. ...
Due to polluting emissions released to the atmosphere and the costs associated with fuel consumption, it is of interest to reduce the quantity of fuel required to power a flight. Trajectory optimization represents an important opportunity to reduce fuel consumption as many flights do not fly at their optimal speeds and altitudes. In this paper, an algorithm able to optimize the 3D flight reference trajectory of a commercial aircraft was optimized taking into account weather and current airspace constraints such as constant speed, constant altitude segments, and step-climbs. Weather forecasts were obtained from weather Canada website and the aircraft fuel consumption was computed from a numerical performance database. The reference aircraft flight plans were obtained from the website Flightaware. A graph was created around the flight of reference to obtain a more economical trajectory. Results showed that up to 8% of fuel burned can be reduced in a long haul flight.
Air traffic plays a crucial role in the global economy and connectivity, directly strengthening international trade, job creation, and global connectivity. The number of flights is predicted to increase from 2024 to 2050. However, these increases in traffic numbers will also lead to a rise in fuel consumption and CO2 emission values. Therefore, optimizing the cruise altitude can significantly increase the specific range and lower CO2 emissions. Various factors, including cruise altitude, airspeed, mass, weather conditions, and air traffic management, alter the CO2 emissions of a flight. The air traffic system assigns a flight level for each aircraft based on the current air traffic situation. Aircraft can use three flight regimes for cruise operations: constant altitude and lift coefficient, constant airspeed and lift coefficient, and constant airspeed and altitude. The study aims to calculate the CO2 emission for all flight regimes using a linear regression equation. The flight regime with constant altitude and lift coefficient produces approximately 1.6% more CO2 emissions than the constant airspeed and lift coefficient. In addition, the constant altitude and airspeed flight regime also leads to approximately 4.4% more CO2 emissions than the constant airspeed and lift coefficient. Besides, the Ordinary Least Squares linear regression equation has an R2 = 0.958 for calculating total CO2 emission using the initial weight of the aircraft, initial air density, initial airspeed, initial lift coefficient at the beginning of the cruise phase, distance, aircraft type and flight regime information.
Planned maintenance is required by licensed maintenance organizations to detect and prevent performance degradation in aircraft engines. In the literature, engine performance is evaluated with parameters that show engine performance. Fuel flow parameter is one of the important parameters that shows engine performance. In the models developed earlier, no engine performance evaluation was made with the fuel flow parameter at all stages from the take-off to the landing of the aircraft. In this study, fuel flow parameter is estimated with over 99.9% accuracy by using artificial neural network in MATLAB® software. In order to detect the engine performance deterioration of the aircraft, the fuel flow values obtained from the artificial neural network and confidence intervals with 99% confidence level were established. Each value taken from the fuel flow sensor is evaluated by the model in all flight phases. In the model, engine performance is considered normal if the fuel flow value is within the confidence interval, and abnormal (anomaly) if it is outside the confidence interval. An accuracy of over 99.9% was achieved and results of this study showed that fuel flow rate of the engine of interest was within the confidence interval (no performance deterioration).
This paper aims to perform accurate prediction of fuel flow (FF) by employing various models: deep learning (DL), random forest (RF), generalized linear model (GLM), and the Eurocontrol Base of Aircraft Data (BADA) model, and to examine the link between FF and different aircraft performance parameters. The flight data set used in this study is obtained from real turbofan engine narrow-body aircraft performing short-distance domestic subsonic flights, containing a total of 2,674 cruise flights between 31 city pairs. Several statistical error analyses are conducted to compare the performance of the models. Root mean square error, mean absolute error, and mean squared error values for DL are calculated to be 0.01, 0.008, and 0.0001, respectively. On the coefficient of determination ( [Formula: see text]) test for validation, the DL model has the highest value of 0.94. Results of the analysis in this paper show that the DL model offers the best ability to predict FF in all statistical tests, which makes it the best-suited model to estimate FF. These findings can provide the means to make more efficient trajectory planning and forecasts in air traffic management, and more accurately predict fuel consumption of aircraft, thereby decreasing emission levels of carbon gases and of various pollutants and airline operating expenses from fuel costs.
The disrupted flight recovery problem is well-studied in the literature owing to its significant impact on airlines and passengers. In this work, we consider the disrupted flight recovery problem with two new realistic aspects, i.e., a new implementation for changing flight duration as a recovery option and considering the aircraft assignment constraints. Firstly, we develop a new mixed-integer quadratic programming model encapsulating a functional relationship between the reduced flight duration and the changes in fuel consumption using a piecewise function. Secondly, we propose an improved column generation approach to solve some scenarios based on actual flight data obtained from an airline. Lastly, the experimental results show that the improved column generation algorithm can obtain the optimal solution for all scenarios. Compared with not considering changing the flight duration, considering changing the flight duration can save about 24% of recovery costs on average. In addition, we analyze the effect of enforcing aircraft assignment constraints and different fuel prices on recovery costs. Based on the experimental results, we discuss how to support practitioners in choosing the appropriate combination of recovery options.
The global aviation fleet numbers rise as a result of increase in flight numbers and hours. Aviation transportation industry causes the environmental degradation and global warming effect. In this regard, greener and sustainable aviation issues have been more interested in researchers, engine manufacturers, and society in recent years. This study presents a model about sustainable aviation for finding the environmental effects and sustainable level of aero-engine systems. These metrics consist of the general aviation metrics, energy-based metrics, exergy-based aviation metrics, environmental-based metrics, and sustainability-based metrics. These aviation metrics are applied to a real turbofan engine to assess the engine's sustainability level and its main components.
Purpose
The purpose of this paper is to create and analyze the effectiveness of a new runway system, which is totally created for the future free route operations.
Design/methodology/approach
This paper researches and analyses the new generated runway concept with the fast time simulation method. Fuel consumption and environmental effect of the new runway system are calculated based on simulation results.
Findings
According to different traffic density analyses the Omnidirectional Runway with Infinite Heading (ORIH) reduced fuel consumption and CO 2 emissions up to 46.97%. Also the total emissions of the ORIH concept, for the hydro carbon (HC), carbon monoxide (CO) and nitrogen oxides (NOx) pollutants were lower than the total emissions with the conventional runway up to 83.13, 74.36 and 51.49%, respectively.
Practical implications
Free route airspaces bring many advantages to air traffic management and airline operations. Direct routes become available from airport to airport thanks to free route airspace concept. However, conventional single runway structure does not allow aircraft operations for every direction. The landing and take-off operations of a conventional airport with a single runway must be executed with only two heading direction. This limitation brings a bottleneck direct approach and departure route usage as convenient with free route airspace concept. This paper suggests and analyzes the omnidirectional runway with infinite heading (ORIH) as a solution for free route airspace.
Originality/value
This paper suggests a new and futuristic runway design and operation for the free route operations. This paper has its originality from the suggested and newly created runway system.
Fuel consumption prediction for transport aircrafts is critical for optimally managing fuel, saving energy costs, minimizing fuel emissions, optimizing aircraft trajectories and for efficient air traffic management. This paper shares experiences associated with developing machine learning based fuel flow and drag polar models for twin-engine business jet aircrafts. A set of neural network topologies, along with different activation functions, is analyzed with respect to the fuel flow prediction accuracies. Further, machine learning models are leveraged towards arriving at high fidelity drag polar model. Potential applications of the developed models include fine tuning the traditional fuel prediction models and assessing impact of factors such aircraft aging, engine performance degradation, on fuel consumption.
Purpose
The purpose of this paper is to create a new fuel flow rate model for the descent phase of the flight using particle swarm optimization (PSO).
Design/methodology/approach
A new fuel flow rate model was developed for the descent phase of the B737-800 aircraft, which is frequently used in commercial air transport using PSO method. For the analysis, the actual flight data records (FDRs) data containing the fuel flow rate, speed, altitude, engine speed, time and many more data were used. In this regard, an empirical formula has been created that gives real fuel flow rate values as a function of altitude and true airspeed. In addition, in the fuel flow rate predictions made for the descent phase of the specified aircraft, a different model has been created that can be used without any optimization process when FDR data are not available for a specific aircraft take-off weight condition.
Findings
The error analysis applied to the models showed that both models predict real fuel flow rate values with high precision.
Practical implications
Because of the high accuracy of the PSO model, it is thought to be useful in air traffic management, decision support systems, models used for trajectory prediction, aircraft performance models, strategies used to reduce fuel consumption and emissions because of fuel consumption.
Originality/value
This study is the first fuel flow rate model for descent flight using PSO algorithm. The use of real FDR data in the analysis shows the originality of this study.
A first attempt is made to use recently developed, non-conventional Artificial Neural Network (ANN) models with Multilayer Perceptron (MLP), Radial Basis Function (RBF) and Adaptive Neuro-Fuzzy Interference System (ANFIS) architectures to predict the fuel flow rate of a commercial aircraft using real data obtained from Flight Data Records (FDRs) of the cruise, climb and descent phases. The training of the architectures with a single hidden layer is performed by utilising the Delta-Bar-Delta (DBD), Conjugate Gradient (CG) and Quickprop (QP) algorithms. The optimum network topologies are sought by varying the number of processing elements in the hidden layer of the networks using a trial-and-error method. An evaluation of the approximate fuel intake values against the ideal fuel intake data from the FDRs indicates a good fit for all three ANN models. Thus, more accurate fuel intake estimations can be obtained by applying the RBF-ANN model during the climb and descent flight stages, whereas the MLP-ANN model is more effective for the cruise phase. The best accuracy obtained in terms of the linear correlation coefficient is 0.99988, 0.91946 and 0.95252 for the climb, cruise and descent phase, respectively.
Aircraft performance parameters play a critical role in maintaining economic and environmental sustainability in aviation. Furthermore, the ability to calculate aircraft performance parameters accurately for the cruise range contributes to aviation in areas such as the preliminary design of aircraft and air traffic management. This study is focused on cruise range performance, as this is critical to both the evaluation and understanding of the economic and environmental impacts of commercial aircraft. Quick Access Recorders (QAR) data were used for more accurate analysis of the cruise range. The QAR data used in this study included 6,574 short-distance domestic flights by narrow-body turbofan commercial aircraft between 31 different city pairs. To obtain a more accurate cruise range equation, parameters affecting the cruise range performance were determined and studied. First, the drag polar model was improved to take the cambered profile, compressibility effects and cruise airspeeds of commercial aircraft into consideration using the real flight data. Second, Thrust-Specific Fuel Consumption (TSFC) models were compared and the most suitable one for the cruise phase was selected. After these steps, cruise range values were calculated using the Breguet range equation with these improved parameters. When the results of this enhanced range model were compared with the real flight data, the mean absolute percentage error (MAPE) was found to be 2.5% for all the Aircraft and Engine Type Groups (AETGs) considered in the data. This figure corresponds to a 7.9% smaller error than provided by previous range models based on simple parabolic drag polar and TSFC models. According to these results, the application of a simple parabolic drag polar and TSFC is not appropriate for cruise range calculations.
The one of ways to moderate aviation emissions resulting from aircraft engines is to comprehend formation mechanism of environmental impacts. In this article, exergo-environmental aspects of the Boeing 747 propulsion system (PW4000 turbofan) used in long range air transport is dealt with life cycle assesment method for eight different flight phases. Environmental impact regarding the turbofan engine and its components was calculated using Eco-indicator points per unit second (Pts/s). Results show that environmental impact related to exergy destruction for the combustor changes from 8.16 mPts/s (at cruise phase) to 24.35 mPts/s at (take-off phase), whereas its environmental impact related to component production and maintenance phases is found as 0.374 mPts/s. On the other hand, exergo-environmental factor of the whole PW4000 engine is calculated as the lowest with 15.83 % and 17.22 % at take off and climb-out phases, respectively. Moreover, a new environmental indicator, namely, specific thrust environmental effect index (mPts/kN.s) is defined in this study. In this context, environmental effect index of fan and core specific thrust is estimated the lowest with 0.065 mPts/kN.s and 0.107 mPts/kN.s at cruise phase, respectively. Especially, take-off and climb out phases seem to be the two where the PW4000 behaviour affects environmental effect to the greatest degree. The reason for this could be attributed that these two phases have relatively higher thrust settings. However, considering cumulative environmental impact, cruise phase has the highest environmental impact from exhaust air of the fan and core as 54.2 Pts and 74.41 Pts, respectively. Consequently, it is expected that the method used in present study could help comparing aircraft flight phases in terms of exergo based-environmental impact.
Accurate estimation of aircraft fuel consumption is critical for airlines in terms of safety and profitability. In current practice, estimation of fuel consumption for a flight trip is usually done by engineering approaches, which mainly consider physical factors, e.g., planned weather and planned cruise level. However, the actual performance of a flight usually deviates from such estimation. Therefore, we propose a novel self-organizing constructive neural network (CNN) that features a cascade architecture and analytically determines connection weights to estimate the trip fuel of a flight. The proposed method generates non-redundant and linearly independent hidden units by an orthogonal linear transformation of operational parameters to achieve the best least-squares solution. Our findings provide insights for the aviation industry in controlling airlines’ excess fuel consumption.
Background
The centrifugal vane pump driven by three-phase AC motor is the key for modern equipments. So its health status affects the system operating performance and safety directly. Modeling and simulation is effective way for system analysis.
Methods
Based on the phased-mission feature in behavior and the redundancy design in structure, the mathematical model of tank-to-engine fuel feed system (T-EFFS) is obtained. Both damage modes arising frequently in the given type system are tracked, one is fuel feed pump seal damage due to fatigue, and the other is vane damage due to corrosion. Then multiple degradation T-EFFS model is established to simulate system outlet fuel pressure under different damage modes. And morphological spectrum decrement index is used to describe the system damage status.
Results
The results show that T-EFFS model can describe the phased-mission behavior of the system, and meet the requirement of the fuel flow rate for entire mission profile. Then fuel pressure dropping of T-EFFS with cumulative effect of vane damage and crack growth under different behavior modes are simulated along its life span.
Conclusion
The work is expected to provide model and data support for the subsequent investigate. It can be used to fit the system health background curve, predict the system performance degradation trend at some given life points, further evaluate the corresponding remaining useful life.
Highlights
• Average weights are inconsistent with standard passenger weights.
• Deviations from standard passenger weights significantly affect aircraft performance.
• Overestimation of payload weight increases airline fuel cost.
• Increases in aircraft payload reduces fuel capacity in turn reducing range.
• Increasing prevalence of overweight and obese passengers has an effect on safety requirements e.g. weight and balance, take-off and landing distance.
In this study, the effects of the flight-path angle (FPA) ranging between 1.0 and 4.5 deg during a continuous descent approach, on certain fuel-related parameters such as fuel flow, fuel burn per 1000 ft of altitude, and specific range, are investigated. The dataset, obtained from Turkish Airlines, includes 4384 eligible flight data records of narrow-bodied commercial aircraft performing 9351 domestic flights between 30 city pairs, across Turkey. The results indicate that the fuel flow is a strong linear function of FPA up to 2.5–3.0 deg for all of the aircraft types, whereas the effect diminishes above 3.0 deg. There is a monotonic decrease of the fuel burn per 1000 ft of altitude with an increase in the FPA, with the trend being stronger than that for fuel flow. Even though the fuel consumption of the descent flight significantly decreases with steeper FPAs, the effect of the FPA on the total fuel consumption of the flight seems not as straightforward as it does when considering only the descent phase. A case study based on this model indicates a U-shaped pattern for total fuel burn with an increase in the FPA, in which the highest fuel saving relative to 1.0 deg of the FPA is calculated to be 14.0% (191 kg) at 2.5 deg of the FPA.
Departure climb angles differ with respect to factors such as obstacles within the departure track, meteorological conditions, and cost index input, most of which have a dynamic nature to some extent. In this sense, it is relevant to perform parametric analyses to capture the outcomes of various climb angles. Therefore, in this Paper, the effects of the departure climb angle, mainly on fuel consumption and nitrogen oxides emissions, are quantified for an increment level as low as 0.25 deg of the departure climb angle. Using actual flight data of a large number of flights, the impacts of climb angle variations are statistically analyzed. The fuel burn and nitrogen oxides emissions tend to increase by 9–19 kg and 0.3–0.7 kg per degree of climb angle for the departure climb phase between takeoff and a further 5 n mile horizontal distance. Furthermore, this trend is a function of aircraft mass, which leads to a ∼2% (fuel burn) and a ∼5% (nitrogen oxides) increase for each 2 ton increase in aircraft mass. The current Paper also investigates the effects of the average climb angle in a broader sense, associated with cruise flights. Applying a steeper average climb angle during climb to 30,000 ft, the marginal reductions in fuel burn and nitrogen oxides are found to be 157 and 3.4 kg, whereas they are 65 and 3 kg for the combined climb and cruise phases, respectively.
This paper examines the potential fuel efficiency benefits of cruise altitude and speed optimization using historical fight path records. Results are presented for a subset of domestic US flights in 2012 as well as for long haul flights tracked by the European IAGOS atmospheric research program between 2010 and 2013. For a given lateral flight route, there exists an optimal combination of altitude and speed. Analysis of 217, 000 flights in domestic US airspace has shown average potential savings of up to 1.96% for altitude optimization or 1.93% for speed optimization. International flights may be subject to different airline and/or air traffic management procedures and constraints. Examination of 3, 478 long-haul flights, representing three airlines and a single aircraft type over a four-year period, indicates average potential savings of up to 0.87% for altitude optimization or 1.81% for speed optimization. This is equivalent to a mean fuel savings of 905 pounds and 1981 pounds per flight, respectively. Due to the limited sample set for long haul flight records, conclusions from this stage of the international study are limited to the specific airlines and aircraft types included in the IAGOS measurement program.
A design methodology based on the principles of system analysis was used to design a noise abatement approach procedure for Louisville International Airport. In a flight demonstration test, the procedure was shown to reduce the A-weighted peak noise level at seven locations along the flight path by 3.9 to 6.5 dBA, and to reduce the fuel consumed during approach by 400 to 500 lb (181 to 227 kg). The noise reduction is significant given that a 3-dB difference represents a 50% reduction in acoustic energy and is noticeable to the human ear, and the 7% reduction in the size of the 50 day night average noise level (DNL) contour that would result if all aircraft were to perform the procedure. The fuel saving is also significant, given the financial benefit to airlines and the accompanying reduction in gaseous and particulate emissions. Although the analysis of aircraft performance data showed how pilot delay, in combination with auto-throttle and flight management system logic, can result in deviations from the desired trajectory, the results confirm that near-term implementation of this advanced noise abatement procedure is possible. The results also provide ample motivation for proposed pilot cueing solutions and low-noise guidance features in flight management systems.
Accurate modeling of airplane fuel consumption is necessary for air transportation policy-makers to properly adjudicate trades between competing environmental and economic demands. Existing public models used for computing terminal-area airplane fuel consumption have been shown to have substantial errors, potentially leading to erroneous policy and investment decisions. The method of modeling fuel consumption proposed in this paper was developed using data from a major airplane manufacturer. When compared with airline performance/operational data, this proposed method has been shown to accurately predict fuel consumption in the terminal area. The proposed method uses airplane performance data from publicly available environmental models supported by the Federal Aviation Administration and others. The proposed method has sufficient generality to protect the proprietary interests of the manufacturer, while still having adequate fidelity to analyze low-speed airplane operations in the terminal area. This improved methodology will enable more informed decisions by policy-makers seeking to account for the effects of fuel consumption and airplane emissions on plans for future airspace and airport designs.
While quantification of the effects of NO X and water vapor is still at an early stage there is evidence that contrail formation could make a significant contribution to global warming. This paper builds on previous research that analyzed a policy of restricting air transport cruise altitudes to eliminate contrail formation. Our previous work (Williams et al., 2002) examined altitude restrictions in European air space and concluded that this could be a beneficial policy for reducing climate change impacts from aviation. Since most of the flights in European air space are short haul flights, this paper evaluates the trade-offs between altitude restrictions, fuel burn and journey times for longer haul flights of up to 6000nm. Our focus is on the North Atlantic and US airspace and we examine potential contrail fraction to determine optimal cruise altitudes for reducing contrail formation. Changes in fuel burn and travel times associated with flight levels of 18,000ft and 31,000ft for different aircraft types are analyzed. We find that, in most cases, CO 2 emission increases would be unlikely to entirely counteract the benefit of possible reductions in contrail formation. For some aircraft types, the percentage increase in emitted CO 2 was found to be strongly dependent on journey length. In general, journey times appear not to be a major issue except for some aircraft types. Our results suggest that reducing aircraft cruise altitudes could be a beneficial policy for mitigating climate change impacts from the aviation sector. This is clearly dependent on aircraft type and the distances traveled, but more importantly on ambient atmospheric conditions which can vary significantly between regions and due to daily variation. This suggests that real time flight planning to minimize contrail formation should be investigated as a possible climate mitigation policy.
This paper introduces concepts for the reduction of the cruise altitude of jet-powered transport aircraft. The design analysis is reduced to consideration of six parameters: profile drag, induced drag, structural weight, thrust-specific fuel consumption, gross wing area and relative wing thickness. The analysis is carried out with the concept of specific air range. The key findings are: a reduction in profile drag contributes to the improvement the air range, but it does not affect the optimal cruise altitude; improved specific fuel consumption, reduced vortex drag and reduced structural weight point toward a higher cruise altitude. The search of optimal design points often leads to aircraft with higher cruise altitudes. The conclusion is that conventional configurations tend naturally toward higher altitudes. Various constraints on reduced altitude lead to sub-optimal solutions. An alternative is identified in the trade between air range and altitude. It is concluded that this solution can be viable. A 2000 ft (610 m) reduction in altitude is achievable without additional fuel consumption. A 4000 ft (1220 m) reduction in altitude can be achieved for a 1.5% reduction in air range.
(cont.) fuel burn results below 3000 ft. For emissions, the emissions indices were the most influential uncertainties for the variance in model outputs. By employing the model, this thesis examined three policy options for mitigating aviation emissions. More stringent engine certification standards, continuous descent approach procedures, and derated take-off procedures were analyzed. Uncertainties of the model were carefully accounted for in the fuel burn and emissions scenarios of the policy options. The considered policy options achieved roughly 10-30% reductions in NOx emissions. However, HC and CO emissions rather increased due to higher emissions production rate for the CDA and derated take-off. In addition, the NOx emissions reductions in some cases were not statistically significant given the uncertainty in the modeling tool.
This paper considers the environmental effects of air traffic management speed constraints during the departure phase of flight. We present a CO2 versus noise trade-off study that compares aircraft departure procedures subject to speed constraints with a free speed scenario. A departure route at Gothenburg Landvetter Airport in Sweden is used as a case study and the analysis is based on airline flight recorded data extracted from the Airbus A321 aircraft. Results suggest that CO2 emissions could be reduced by 180 kg per flight if all departure speed constraints were removed at a cost of increased noise exposure below 70 dB(A).
While quantification of the effects of NOx and water vapor is still at an early stage there is evidence that contrail formation could make a significant contribution to global warming. This paper builds on previous research that analyzed a policy of restricting air transport cruise altitudes to eliminate contrail formation. Our previous work [Transport. Res. D 7(6) (2002) 451], examined altitude restrictions in European airspace and concluded that this could be a beneficial policy for reducing climate change impacts from aviation. Since most of the flights in European airspace are short-haul flights, this paper evaluates the trade-offs between altitude restrictions, fuel burn and journey times for longer haul flights of up to 6000 nm. Our focus is on the North Atlantic and US airspace and we examine potential contrail fraction to determine optimal cruise altitudes for reducing contrail formation. Changes in fuel burn and travel times associated with flight levels of 18,000 and 31,000 ft for different aircraft types are analyzed. We find that, in most cases, CO2 emission increases would be unlikely to entirely counteract the benefit of possible reductions in contrail formation. For some aircraft types, the percentage increase in emitted CO2 was found to be strongly dependent on journey length. In general, journey times appear not to be a major issue except for some aircraft types. Our results suggest that reducing aircraft cruise altitudes could be a beneficial policy for mitigating climate change impacts from the aviation sector. This is clearly dependent on aircraft type and the distances traveled, but more importantly on ambient atmospheric conditions which can vary significantly between regions and due to daily variation. This suggests that real time flight planning to minimize contrail formation should be investigated as a possible climate mitigation policy.
This paper presents a case study of modeled arrival operations which utilize descent trajectories optimized for reduced fuel burn and pollutant emissions. Arrival flights descending along optimized vertical profiles are modeled by transforming the descent trajectories of a set of baseline arrival flights, taken from observed radar track data, into descent trajectories at idle throttle. The trajectories of the baseline and modeled arrival flights are described in depth, along with the transformation that connects them. Two implementation scenarios (unconstrained and constrained) of optimized descent procedures during daytime operations are analyzed. In the case of unconstrained optimized descent both the potential benefits and conflicts that result from such operations are quantified. In the case of constrained optimized descent, mitigation strategies are applied which remove the potential conflicts, but also reduce the level of potential benefit. The constrained optimized descent scenario demonstrates that by carefully choosing which level-offs are removed, both benefits can be obtained and conflicts avoided simultaneously. The major conclusion that may be drawn from this study is that procedures for optimized descent arrival operations can be implemented with fuel and emissions savings benefits while avoiding conflicts with other traffic.
Allowing aircraft to descend uninterrupted at low engine power, continuous descent operations promise to maximize fuel efficiency while minimizing environmental impact. Tailored arrivals is a concept for enabling continuous descents under constrained airspace conditions by integrating advanced air and ground automation through digital datalink. Operational trials were completed in January 2007 involving transpacific flights into San Francisco during early morning hours. Leveraging newly deployed Federal Aviation Administration automation in the oceanic environment, trajectory-based clearances were transmitted by datalink to Boeing 777 aircraft equipped with future air navigation system avionics. NASA's prototype ground-based automation for high-density arrival management tailored trajectory clearances to accommodate artificially imposed metering constraints. Upon sharing wind and descent-speed-intent data, ground-based and airborne automation were found to predict meter-fix arrival times to within a mean accuracy of 3 s over a 25 min prediction horizon. Corresponding mean altitude and along-track prediction errors of ground-based automation were ft and n mile, respectively, in comparison with surveillance truth. A benefits analysis suggests Boeing 777 fuel savings of between 200 and 3000 lb per flight (depending highly upon baseline traffic conditions) together with a corresponding reduction in CO 2 emissions of between 700 and 10,000 lb per flight.
In this article the maximum range cruise is analyzed. Wind effects are included in the analysis, taking into account the variation of wind speed with altitude (crosswinds are ignored). The optimal control laws that lead to maximum range are analyzed (unconstrained case); constrained regimes (constant-altitude cruise or constant-Mach cruise) are also analyzed. The maximum range in the optimal regimes (unconstrained and constrained) is studied. The formulation is made for a general aircraft performance model (general drag polar and general specific fuel consumption model), and is particularized for simpler models in order to establish the precise range of validity of some published results. The effects of wind on the optimal control laws and on the maximum range are studied. The accuracy of the incompressible approximation is also studied. Results are presented for a model of a typical twin-engine, wide-body, transport aircraft.
Condensation trails (contrails) are aircraft induced cirrus clouds, which may persist and grow to large cirrus cover in ice-supersaturated air, and may cause a warming of the atmosphere. This paper describes the formation, occurrence, properties and climatic effects of contrails. The global cover by lined-shaped contrails and the radiative impact of line-shaped contrails is smaller than that assessed in an international assessment in 1999. Contrails trigger contrail cirrus with far larger coverage than observed for line-shaped contrails, but still unknown radiative properties. Some model simulations indicate an impact of particles and particle precursors emitted from aircraft engines on cirrus clouds properties. However, the magnitude of this effect cannot yet be assessed. Contrail formation can be avoided only by flying in sufficiently warm and dry air. The formation of contrail cirrus can be reduced by avoiding flights in ice-supersaturated regions of the atmosphere, e.g., by raising the flight level into the lower-most stratosphere. To cite this article: U. Schumann, C. R. Physique 6 (2005).
Performance differences between the aircraft types are natural and they inevitably cause problems in the air traffic system, particularly when slower aircraft types are followed by faster types in a climb or cruise queue. This paper presents the excess fuel consumption impact of aircraft performance differences in the air traffic environment. For this purpose, both climb and cruise phases of a flight mission are analyzed. Revision of the airworthiness regulations and air traffic procedures are suggested. The need for a flight level - cruise performance categorization is also recommended.
This paper presents a detailed estimation of fuel consumption and emissions during taxi operations using aircraft position data from actual operations at Dallas/Fort Worth International Airport. Making assumptions of the thrust level during each state, fuel flow and emission index values from International Civil Aviation Organization’s databank are extrapolated. This provides a relative comparison of all the taxi phases and their contribution to the total effect. Analysis reveals that stop-and-go situations, resulting primarily from congestion on airport’s taxiway system, account for approximately 18% of fuel consumed. The states of idling and taxiing at constant speed or braking were found to be the two largest sources of fuel burn and emissions, and the model estimates are sensitive to the thrust level assumptions for these states.Research highlights► Using detailed taxi data from DFW, we estimate fuel consumption and emissions. ► Stop-and-go situations constitute 18% of fuel consumed during taxi. ► Idling and taxiing at constant speed are the two largest sources of fuel burnt.
Aircraft induced cirrus clouds have a major effect on climate. Here we use operational radiosonde data with high vertical resolution to estimate the effect of a small change in flight altitudes on the contrail and cirrus formation. It is shown that a substantial fraction of contrails and contrail induced cirrus can be avoided by relatively small changes in flight level, due to the shallowness of ice-super-saturation layers.
Environmental concerns, as well as the expected depletion of fossil fuel resources, have become the driving forces for research and development towards the introduction of hydrogen energy into air traffic. The present paper is a summary of a study that was carried out within the European sponsored project CRYOPLANE, co-ordinated by Airbus Germany. The objectives of this study are to re-optimise and compare two equivalent medium-range aircraft - one kerosene-fuelled and one LH2-fuelled - for reduced cruise altitude, from an environmental point of view. By lowering the cruise altitude, the contribution to global warming might be reduced at the expense of increased fuel consumption and pollutant emissions. In order to assess the global impact, in terms of global warming, from the emissions discharged on a certain mission, a simple parametric model is employed. The results suggest that introduction of cryoplanes will improve the environmental performance, particularly in terms of global warming. Provided that an increase in fuel consumption in the order of 10% and an increase in TOM of a few percent are accepted, the results suggest that cryoplanes should cruise at an altitude of about 2-3 km below where conventional aircraft cruise today in order to considerably reduce the environmental impact. © 2004 Swedish Defence Research Agency. Published by Elsevier SAS. All rights reserved.
This report describes the development of a three-dimensional database of aircraft fuel burn and emissions (fuel burned, NOx, CO, and hydrocarbons) from scheduled commercial aircraft for each month of 1992. The seasonal variation in aircraft emissions was calculated for selected regions (global, North America, Europe, North Atlantic, and North Pacific). A series of parametric calculations were done to quantify the possible errors introduced from making approximations necessary to calculate the global emission inventory. The effects of wind, temperature, load factor, payload, and fuel tankering on fuel burn were evaluated to identify how they might affect the accuracy of aircraft emission inventories. These emissions inventories are available for use by atmospheric scientists conducting the Atmospheric Effects of Aviation Project (AEAP) modeling studies. Fuel burned and emissions of nitrogen oxides (NOx as N02), carbon monoxide, and hydrocarbons have been calculated on a 1 degree latitude x 1 degree longitude x 1 kilometer altitude grid and delivered to NASA as electronic files.
Green delay programs absorbing ATFM delay by flying at minimum fuel speed
- X Prats
- M Hansen
X. Prats, M. Hansen, Green delay programs absorbing ATFM delay by flying at
minimum fuel speed, in: Ninth USA/Europe Air Traffic Management Research
and Development Seminar, 2011.
User Manual for the Base of Aircraft Data (BADA)
- Eurocontrol
Eurocontrol, User Manual for the Base of Aircraft Data (BADA), Revision 3.6,
EEC Note No. 10/04, Eurocontrol Experimental Center, Brussels, 2004.