Airbus A320 Research Articles

Numerical Simulation of the Novel Coronavirus Spread in Commercial Aircraft Cabin

Passengers carrying the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a commercial aircraft cabin may infect other passengers and the cabin crew. In this study, a cabin model of the seven-row Airbus A320 aircraft is constructed and meshed for simulating the SARS-CoV-2 spread in the cabin with a virus carrier using the Computational Fluid Dynamics (CFD) modeling tool. The passengers’ infection risk is also quantified with the susceptible exposure index (SEI) method. The results show that the virus spreads to the ceiling of the cabin within 50 s of the virus carrier’s normal breathing. Coughing makes the virus spread to the front three rows with a higher mass fraction. While the high mass fraction areas always stay on the same side of the aisle as the virus carrier, the adjacent passengers and the passengers in the back two rows are affected more than the others when the virus carrier breathes normally. Spread patterns under the carrier’s two breath conditions, normal breath and cough, were numerically simulated.

Future of Electrical Aircraft Energy Power Systems: An Architecture Review

This article presents an in-depth analysis of all electric-aircraft (AEA) architectures. This work aims to provide a global vision of the current AEA state of the art, to estimate the main technological gaps and drivers, and to identify the most promising architecture configuration for future electrical aircraft in the context of a twin-propeller 20-MW aircraft. The comparison between architectures is done based on three different figures of merit: reliability, efficiency, and specific power density. The methodology presented and the trade studies are applied to a narrowbody aircraft of 20 MW, equivalent to an Airbus A320, and following current efforts of government agencies to achieve cleaner air mobility within the next two decades.

Practical Use of Composite Materials Used in Military Aircraft.

The article presents a comparative characterization of the structural materials (composites and metals) used in modern aviation structures, focusing on the airframe structure of the most modern aircraft (Airbus A-380, Boeing B-787, and JSF F-35). Selected design and operational problems were analysed, with particular emphasis on composites and light metals (aluminium). For this purpose, the Shore’s method was used for the analysis of the obtained strength results and the programming environment (ANSYS, SolidWorks) required to simulate the GLARE 3 2/1-04 composite. The focus was on highlighting the differences in the construction and modelling of these materials resulting from their various structures (isotropy and anisotropy), e.g., by analyzing the mechanics of metal destruction and comparing it with the composite material. In terms of solving the problems of finite element analysis FEM, tests have been carried out on two samples made of an aluminium alloy and a fiberglass composite. The focus was on highlighting the differences in the construction and modelling of these materials resulting from their various structures (isotropy and anisotropy), e.g., by analyzing the mechanics of metal destruction and comparing it with the composite material. On the basis of the obtained results, the preferred variant was selected, in terms of displacements, stresses, and deformations. In the final part of the work, based on the conducted literature analysis and the conducted research (analysis, simulations, and tests), significant observations and final conclusions, reflected in practical applications, were formulated.

Flight Delay Causes at Selected Visegrad Group International Airports

The aim of this article is to analyse the flight delay causes at base airports (Prague, Brno, Ostrava, Budapest, Bratislava, Katowice, and Warsaw), with a special focus on a selected airline company operating in the central European region. To process the data, methods of multivariable statistics, namely tests of independence in contingency tables, the Kruskal-Wallis testing, cluster analysis, and correspondence analysis were used. Apparently, both charter and scheduled flights have the same percentage of delayed flights, delays occur most frequently in June, and Boeing 737-800 reported delays more frequently than Airbus A320. The research has shown that the highest number of delayed flights occurs in Budapest, the lowest number in Katowice. During the night, short delays occur most often, long delays most frequently arise in the evening. The most common cause for longer delays is technical maintenance or an aircraft defect and previously delayed flights. The flight dispatch by supplier companies is the source accounting only for rather short delays. Overall, the delayed flights frequency increases with the size of the city and the airport.

Acoustic emission source location in complex aircraft structures using three closely spaced sensors

The use of three piezoelectric sensors in a small array has previously been investigated to assess its ability to locate Acoustic Emission (AE) sources in simple aluminium and composite structures. It has been theorised that this approach could be used within wireless systems to monitor AE in aircraft, as the close spacing of the sensors removes the need for power-intensive time synchronisation between nodes and reduces excessive cabling. There are, however, two major limitations to this, primarily that the localisation techniques used are only viable within simple structures and additionally that the high computational requirements of the continuous wavelet transform which the technique utilises is infeasible for a low power system. This paper presents modifications to this approach, including the novel second differential method for single sensor modal analysis, which enables the technique to locate AE events within complex structures. A mapping technique is also presented, which accounts for complexity and varying wave velocity in composite structures. Testing is presented which uses artificial sources on a range of structures, from simple plates to an Airbus A350 aircraft wing, with a high level of accuracy and repeatability shown.

Development of Flight Multifunctional Indicator Based on A320 and B737 NG Flight Indicator

The objectives of this research are: to know the concept of modeling and simulation the cockpit display based on disadvantages and differences between A320 and B737NG; to offer the development and new technology to design the development (new) flight instruments of the display based on Airbus A320 and Boeing B737 NG flight instrument technology. Methodologies that have been used in this research are literature review, interview/discussion/questionnaire, and descriptive analysis. Questionnaire towards the users/pilots who flies airplane A320 or B737 NG. For the questionnaire, the Likert-scale method is utilized to collect data and information. This research result’s in finding that: 1. the technology of flight instrument system between A320 and B737 NG visually displays similarity with several differences such as ergonomic side, ECAM technology, and VSD technology. 2. Based on works of literature review and response from the users/pilots, the author finds and proposes several technologies or requirements to apply in the new type model of PFD and Multi-function Display, they are including: PFD and MFD merged into one display only with some additional menu buttons; ECAM + engine warning display, ECAM + systems display, and digital instruction to solve the problem merged into one display only with some additional buttons; display design is using the fully digital display, computerized system, LCD technology, VSD, and EHSI technology, and layout display is using configuration “basic T”; standby flight instrument merged into one display only with some additional menu buttons

Travelling Waves Approach in a Parabolic Coupled System for Modelling the Behaviour of Substances in a Fuel Tank

The aim of this work was to provide a formulation of a non-linear diffusion model with forced convection in the form of a reaction–absorption system. The model was studied with analytical and numerical approaches in the frame of the parabolic operators theory. In addition, the solutions are applied to a gas interaction phenomenon with the intention of producing an inerted ullage in an Airbus A320 aircraft centre fuel tank. We made use of the travelling wave (TW) solutions approach to study the existence of solutions, stability and the precise evolution of profiles. The application exercise sought to answer a key question for aerospace sciences which can be formulated as the time required to ensure an aircraft fuel tank is safe (inerted) to prevent explosion due to the presence of oxygen in the tank ullage.

Evaluation of the aircraft fuel economy using advanced statistics and machine learning

Fuel represents a significant proportion of an airline’s operating costs. Statistical analyses and physical models have been used to monitor and estimate fuel consumption up to now, but these can have considerable inaccuracies. This means that, currently, there are no suitable detection methods for the evaluation of aircraft retrofits, of which some only suggest a fuel efficiency potential in the tenths of a percent range. This article examines suitable assessments of the fuel economy of aircraft and especially aircraft with and without retrofitting. For this purpose, the effects of technical influences such as measurement errors and external uncertainties such as turbulence on the evaluation of the fuel economy are examined in more detail. The focus of the article is on a discussion of possible optimization potentials of conventional statistical evaluation methods, especially regarding possible misinterpretations and spurious correlations. This discussion is exemplarily based on a case study of simulated flight data of an Airbus A320 (with and without improved wing tips (sharklets) as an exemplary retrofit). For this purpose, a suitable simulation environment is presented in which relevant environmental parameters such as wind and turbulence can be set, and measurement errors in the recorded data can be manipulated. It is found that measurement errors as well as turbulence can lead to a bias in key figures that are used for the evaluation of fuel flow signals. The effect of turbulence can partly be mitigated by the use of an improved key figure the authors propose. The investigation is also carried out using a data-based evaluation method to simulate the fuel flow using a machine learning model (random forests), whereby the effects of turbulence and measurement errors significantly influence the fuel flow predicted by the model in the same order of magnitude as potential retrofit measures.

Cleaner burning aviation fuels can reduce contrail cloudiness

Contrail cirrus account for the major share of aviation’s climate impact. Yet, the links between jet fuel composition, contrail microphysics and climate impact remain unresolved. Here we present unique observations from two DLR-NASA aircraft campaigns that measured exhaust and contrail characteristics of an Airbus A320 burning either standard jet fuels or low aromatic sustainable aviation fuel blends. Our results show that soot particles can regulate the number of contrail cirrus ice crystals for current emission levels. We provide experimental evidence that burning low aromatic sustainable aviation fuel can result in a 50 to 70% reduction in soot and ice number concentrations and an increase in ice crystal size. Reduced contrail ice numbers cause less energy deposition in the atmosphere and less warming. Meaningful reductions in aviation’s climate impact could therefore be obtained from the widespread adoptation of low aromatic fuels, and from regulations to lower the maximum aromatic fuel content.

Developing prescriptive maintenance strategies in the aviation industry based on a discrete-event simulation framework for post-prognostics decision making

The aviation industry is facing an ever-increasing competition to lower its operating cost. Simultaneously, new factors, such as sustainability and customer experience, become more important to differentiate from competitors. As aircraft maintenance contributes about 20% to the overall cost of airline operations and can significantly influence other objectives of an airline as well, maintenance providers are required to constantly lower their cost share and contribute to a more reliable and sustainable aircraft operation. Subsequently, new condition-monitoring technologies have emerged that are expected to improve maintenance operations by reducing cost and increasing the aircraft’s availability. As many of these technologies are still in their technological infancy, it is necessary to determine the expected benefit for the airline operations with the given technological maturity and to develop suitable maintenance strategies that incorporate the newly gained insights. With this paper, a discrete-event simulation framework is developed that uses established parameters to describe a condition-monitoring technology’s performance and subsequently develops a suitable prescriptive maintenance strategy. Therefore, it enables the adjustment of the optimization goal for the developed strategy to incorporate performance features beyond the frequently used financial indicators. The developed capabilities will be demonstrated for the tire pressure measurement task of an Airbus A320.

Estimating runway veer-off risk using a Bayesian network with flight data

Risk assessments in airline operations are mostly qualitative, despite abundant data from programmes such as flight data monitoring (FDM) and flight operations quality assurance (FOQA). In this paper, features relating to runway excursion causal factors are extracted from flight data from over 310,448 flights from Airbus A320 series aircraft flown on a European network. The data is combined with meteorological data to provide additional features.Bayesian networks are then learnt from the feature set, and two network learning algorithms are compared, Bayesian Search and Greedy Thick Thinning (GTT). Cross-validation of the resulting networks shows both algorithms produce similarly performing networks, and a subjective analysis concludes that the GTT algorithm is marginally preferred.The resulting networks produce relative probabilities, which airlines can use to quantitatively assess runway veer-off risk under different scenarios, such as different meteorological conditions and unstable approaches.This paper's main finding is that by utilising existing data sources, such as FDM and weather databases, airlines can create and use Bayesian networks alongside their existing qualitative risk assessment methods to provide quantitative risk assessment and understand the effect of different conditions on those risks. This is not possible with current methods in use by airlines.The method described can be extended to other operational safety risks, such as runway overrun.

Method for designing multi-input system identification signals using a compact time-frequency representation

A flight test campaign for system identification is a costly and time-consuming task. Models derived from wind tunnel experiments and CFD calculations must be validated and/or updated with flight data to match the real aircraft stability and control characteristics. Classical maneuvers for system identification are mostly one-surface-at-a-time inputs and need to be performed several times at each flight condition. Various methods for defining very rich multi-axis maneuvers, for instance based on multisine/sum of sines signals, already exist. A new design method based on the wavelet transform allowing the definition of multi-axis inputs in the time-frequency domain has been developed. The compact representation chosen allows the user to define fairly complex maneuvers with very few parameters. This method is demonstrated using simulated flight test data from a high-quality Airbus A320 dynamic model. System identification is then performed with this data, and the results show that aerodynamic parameters can still be accurately estimated from these fairly simple multi-axis maneuvers.

The effects of through tool cryogenic machining on the hole quality in GLARE® fibre metal laminates

GLARE® is a composite-metal laminate currently used in the Airbus A380 fuselage due to its excellent impact and fatigue performance. GLARE® undergo extensive drilling for riveting purposes making it prone to thermal effects and increased tool wear. Therefore, using coolants becomes necessary, however, conventional coolants can lead to moisture absorption. An alternative is to use cryogenic coolants due to their positive impact on machining aerospace materials in the past. In this study, through tool cryogenic machining technology is used for machining GLARE® laminates by delivering liquid nitrogen at −196 °C through the spindle allowing the coolant to be in direct and continuous contact with the cutting zone. The aim is to investigate the impact of drilling parameters and cryogenic cooling on surface roughness, hole size, circularity and hardness at hole entry and exit sides. In addition, microstructural evaluation using scanning electron microscopy. The results indicate that the cryogenic cooling improved hole surface finish and gave better hole size at the top, while it had no impact on hole circularity. The hardness was increased at the entry and exit sides of the hole compared to that observed in dry drilling tests while scanning electron microscopy revealed that burr formation was minimised.

On COVID-19-safety ranking of seats in intercontinental commercial aircrafts: A preliminary multiphysics computational perspective.

The evolution of coronavirus disease (COVID-19) into a pandemic has severely hampered the usage of public transit systems. In a post-COVID-19 world, we may see an increased reliance on autonomous cars and personal rapid transit (PRT) systems, with inherent physical distancing, over buses, trains and aircraft for intracity, intercity, and interstate travel. However, air travel would continue to be the dominant mode of intercontinental transportation for humans. In this study, we perform a comprehensive computational analysis, using ANSYS Fluent, of typical intercontinental aircraft ventilation systems to determine the seat where environmental factors are most conducive to human comfort with regards to air quality, protection from orally or nasally released pollutants such as CO2 and coronavirus, and thermal comfort levels. Air velocity, temperature, and air pollutant concentration emitted from the nose/mouth of fellow travelers are considered for both Boeing and Airbus planes. In each plane, first class, business class, and economy class sections were analyzed. We present conclusions as to which is the optimum seat in each section of each plane and provide the data of the environmental conditions to support our inferences. The findings may be used by the general public to decide which seat to occupy for their next intercontinental flight. Alternatively, the commercial airliners can use such a model to plan the occupancy of the aircraft on long-duration intercontinental flights (viz., Airbus A380 and Boeing B747).Electronic Supplementary MaterialSupplementary material is available for this article at 10.1007/s12273-021-0774-y and is accessible for authorized users.

Analysis of Aircraft Routing Strategies for North Atlantic Flights by Using AirTraf 2.0

Climate-optimized routing is an operational measure to effectively reduce the climate impact of aviation with a slight increase in aircraft operating costs. This study examined variations in the flight characteristics among five aircraft routing strategies and discusses several characteristics of those routing strategies concerning typical weather conditions over the North Atlantic. The daily variability in the North Atlantic weather patterns was analyzed by using the European Center Hamburg general circulation model (ECHAM) and the Modular Earth Submodel System (MESSy) Atmospheric Chemistry (EMAC) model in the specified dynamics mode from December 2008 to August 2018. All days of the ten complete winters and summers in the simulations were classified into five weather types for winter and into three types for summer. The obtained frequency for each of the weather types was in good agreement with the literature data; and then representative days for each weather type were selected. Moreover, a total of 103 North Atlantic flights of an Airbus A330 aircraft were simulated with five aircraft routing strategies for each representative day by using the EMAC model with the air traffic simulation submodel AirTraf. For every weather type, climate-optimized routing shows the lowest climate impact, at which a trade-off exists between the operating costs and the climate impact. Cost-optimized routing lies between the time- and fuel-optimized routings and achieves the lowest operating costs by taking the best compromise between flight time and fuel use. The aircraft routing for contrail avoidance shows the second lowest climate impact; however, this routing causes extra operating costs. Our methodology could be extended to statistical analysis based on long-term simulations to clarify the relationship between the aircraft routing characteristics and weather conditions.

Leading Edge Shape Optimization of Whitcomb IL Airfoil in Transonic Flow Using a Multi-Objective Genetic Algorithm (MOGA)

Leading edge shape optimization of transonic airfoils requires creating an airfoil surface that reduces the drag divergence due to transonic shocks by either delaying them or reducing their strength at a given transonic cruise speed while maintaining the lift. Aircrafts like Boeing 757, Airbus A300, Boeing 777 and McDonnell Douglas AV-8B Harrier II use Whitcomb IL supercritical airfoil for efficient aerodynamic performance in transonic conditions. This study employs a multi-objective genetic algorithm for shape optimization of leading edge of the Whitcomb IL airfoil to achieve three objectives, namely dilation of shock, reduction in leading edge radius and increment of lift at a given transonic Mach number and at the given AoA. The commercially available software ICEM CFD and Fluent are employed for calculation of the flow field using the RANS (Reynolds-averaged Navier-Stokes equations) in conjunction with a two equation turbulence model. It is shown that the (MOGA) Multi-objective genetic algorithm can generate superior airfoil compared with Whitcomb IL airfoil by achieving three objectives. The optimized airfoil configuration is validated by wind tunnel testing facility.

A 3D virtual prototype-finite element co-simulation of aircraft hydroplaning on a wet rough runway

ABSTRACT Skid-resistance performance of a runway greatly influences aircraft landing safety. A wet runway significantly increases the incidence rates of aircraft overrun. To study the influence of the skid-resistance performance of a runway on aircraft landing, a co-simulation method is proposed. First, a finite element (FE) model of the local tire-water film-runway simulation is established to obtain the combination coefficient-slip ratio curve of a tire on a wet runway. Second, a global model of an Airbus A320 virtual prototype (VP) is created. Then, on the basis of fuzzy control theory, a two-dimensional (2D) fuzzy controller of the aircraft AB is established. The friction coefficient-slip ratio curve of the tire on the wet runway obtained in the local simulation is introduced into the full-scale hydroplaning simulation model of the aircraft. Finally, the global-local multiscale simulation method is used to analyze the skid-resistance behaviour of the aircraft on three types of runways. It is found that the increase of water film thickness of the pavement and the increase of the grounding speed cause the attenuation of the friction coefficient of a runway, finally causing the reduction of the deceleration rate of the aircraft and the increase of the braking distance.

КОНЦЕПТУАЛЬНОЕ ПРОЕКТИРОВАНИЕ КОНСТРУКЦИИ КРЫЛА ИЛИ ФЮЗЕЛЯЖА МАГИСТРАЛЬНОГО САМОЛЕТА ИЗ МЕТАЛЛОПОЛИМЕРНЫХ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ

The analysis of existing aircraft structures made of metal-polymer composite materials is carried out, and a list of them with passport characteristics is compiled. The Fokker F-27 Friendship, Boeing-777 and Airbus A380, which use ARALL and GLARE materials, were selected as the aircraft under study. Formulas are determined and the distribution of normal force flows between metal and composite elements in the composition of MPCM based on aluminum sheets (aluminum-fiberglass – SIAL- 1-1, SIAL-3-1 and SIAL-1441 (9/8)) and titanium alloys (samples of titanium-carbon fiber from the patent-Example 1 and Example 3). To determine these parameters, the formulas used for a composite structure made of different materials are used. On the basis of the specification known MPCM the modified formula mixture rule for calculating the strength of new materials with a given set of orientation angles of PCM and the presence of layers of sheet metal, a comparison with standard mechanical characteristics and to show the efficiency of these formulas. Using these formulas, you can determine the strength characteristics for an arbitrary composition of the MPCM package. The features of the choice of design permissible stresses for the design of the airframe of a mainline aircraft made of metal-polymer composite material are highlighted. The concept of designing aircraft airframe elements using MPCM is considered. The results of this work will allow us to determine the rational components of the metal-polymer composite material and the structure of their distribution in the airframe design at the preliminary design stage.

The role of very large passenger aircraft in global air transport – a review and outlook to the year 2050

Aviation history has shown an increase in aircraft size in every generation, culminating in the Airbus A380 with a typical capacity of 450 to 600 seats. However, this trend may have come to a halt, as the COVID-19 pandemic has accelerated the retirement of very large aircraft. Already before the pandemic, airlines had begun to switch to more efficient, but smaller, twin-engine widebody aircraft like Airbus 350 and Boeing 787, and Airbus and Boeing had ceased the production of their largest aircraft types. As a result, in a post-COVID world, airlines will have to rely on aircraft considerably smaller than previously. In our paper, we analyze the operational history of very large passenger aircraft and discuss the economic challenges operating these aircraft. Furthermore, we provide a short-, medium and long-term view on strategies for airlines to cope with a situation where very large passenger aircraft will not be available any longer. We argue, that in the short term, airlines can react to this situation with revenue management techniques, effectively crowding out passengers with the least willingness to pay. In the medium term, airlines are likely to react with changing network strategies. New aircraft that will become available in the near future will allow airlines to operate ultra-long-haul routes and long-haul routes on airport pairs with lower demand. In the long term, we argue that aircraft manufacturers may have to re-consider their product portfolio, given the long-term growth prospects of aviation, capacity constraints at major airports and a preference of larger aircraft by airlines in their pursuit to reduce unit costs. Hence, despite the current arguments against very large passenger aircraft, a renaissance of this aircraft class might emerge in the next decades.

Advanced Acoustic Emission Source Location in Aircraft Structural Testing

Acoustic emission (AE) is an in situ Structural Health Monitoring (SHM) technique, where a structure is monitored for the ultrasonic waves produced due to crack growth. A major challenge with AE when applied to aircraft, and other complex structures, is that wave propagation is significantly affected by stiffeners, holes, thickness changes and other complexity. This reduces the accuracy of traditional source location techniques, that are based on a singular propagating wave speed. The Delta-T method enables higher levels of accuracy by mapping the structure and accounting for these changes. In this work AE monitoring equipment was installed on a section of an aluminium Airbus A320 wing. Location trials showed the Delta-T technique improved the average error from 85mm to 23mm, for artificial Hsu-Nielson sources, compared to the commercial standard technique. Testing under fatigue however demonstrated the challenges encountered when inspecting 3D structures (due to multiple signal paths) with significant levels of background noise. Of two cracks identified in the structure, the first of these was successfully detected and located, whilst the other was missed due to high machine noise and unrepresentative loading.