Wide-body Aircraft Research Articles

Operational Noise Abatement Through Control of Climb Profile on Departure

This work introduces a noise abatement procedure for reducing aircraft community noise during departures based on the control of climb profiles via procedural level-offs. The proposed procedure consists of enforcing an altitude restriction along a departure path such that aircraft maintain level flight when overflying strategically selected regions. During this level segment, thrust demand is lower than during climbing flight, which results in lower engine noise. However, this effect must be balanced with the lower aircraft altitude in the level segment, which may reduce the distance between aircraft and observers. Thus, a systematic analysis methodology is needed to design an effective noise abatement procedure based on this technique, which has been developed and is presented in this paper. Modeling results show potential undertrack peak A-weighted noise level reductions of 2–4 decibels for both narrowbody and widebody aircraft in the level-off area depending on the level-off altitude and an associated increase of 1.5–6 decibels in the region where the climb is resumed. An example application of this procedure is demonstrated at Boston Logan Airport, with cumulative changes in noise impacts being assessed for one full day of operations. In this example application, fuel burn penalties are estimated at 37 pounds for a representative narrowbody operation and 142 pounds for a representative widebody operation.

Predicting airport noise impact to 2040: Traffic growth and technology uptake

While the volume of air traffic continues to rise, there are concurrent shifts in aircraft fleets and advancements in technology aimed at enhancing aircraft efficiency, sustainability, and minimizing noise footprints. These simultaneous developments contribute to the complexity of forecasting airport noise associated with future air traffic. This study presents various scenarios of technology adoption for the years 2030 and 2040 at a European airport, namely Dublin Airport, encompassing changes in fleet distribution. Aircraft are classified into different generations to reflect their technological advancements. Projections indicate an anticipated growth in the wide body fleet at Dublin Airport from 2023 to 2040, while the shares of narrow body, regional jet, and turboprop fleets are expected to decline. Each forecast year showcases three distinct technology uptake scenarios, with noise contour lines at Lden = ▪(A) and Lnight = ▪(A) being compared. To assess the impact of these changes on airport noise, the study evaluates alterations in area and population exposure. In general, the findings suggest a trend of increasing population exposure coinciding with the rise in air traffic. Nevertheless, the increase of wide body aircraft at Dublin Airport further increases the noise impact in 2030. Anticipated growth sees new generation 2 aircraft reaching up to ▪ by 2040, leading to a reduction in 2040 noise contour lines compared to 2030—though not returning to the levels observed in 2023.

Experimental investigation on buffet load characteristics of a wide-body aircraft horizontal-tail in take-off configuration

Experimental investigation on buffet load characteristics of a wide-body aircraft horizontal-tail in take-off configuration

Adaptive control method for morphing trailing-edge wing based on deep supervision network and reinforcement learning

The morphing trailing-edge wing can adaptively change its shape according to the different flight conditions, improving cruising efficiency. The control of the morphing trailing edge is a high-dimensional variable and nonlinear problem, facing the difficulty of the high training cost and the difficulty in real-time continuous control. To overcome these difficulties, a novel adaptive control method based on the couple of Deep Supervision Net (DSN) and Deep Reinforcement Learning (DRL) is proposed to solve a control problem of the morphing trailing-edge wing. DSN uses distributed loads to improve aerodynamic prediction accuracy compared to the traditional surrogate models, while DRL conducts real-time control and improves the performance at non-design points compared to the traditional multi-design points optimization. After control, the lift-to-drag ratio at the start point can be increased by 1.36%, and can be increased by 2.61% at the end point tested on a commercial wide-body aircraft model.

Power Setting Estimation of Departing Civil Jet Aircraft Based on Machine Learning

This paper presents an approach for estimating the power setting, indicated as N1, the rotational speed of the low-pressure shaft, of departing civil jet aircraft to be used as input for accurate noise calculations. The method utilizes the machine learning approach random forest regression and is trained using flight data recorder data divided into three departure sections. Each section uses a unique set of three to four model features based on easily accessible data, such as position and airport meteorological data. Unlike previous methods, neither fixed configuration altitudes, aerodynamic coefficients, or engine coefficients, nor takeoff mass or wind information are required as inputs. To assess the performance of the method, noise calculations for departures of five aircraft types, including narrow- and wide-body jet aircraft, were performed. Comparing overall and aircraft-specific noise levels, calculated from estimated N1 versus recorded N1 values from flight data recorder data, revealed small differences of less than 1 dB. Overall, the present machine-learning-based approach provides reliable estimates of power settings for departing civil jet aircraft, offering improved accuracy and avoiding the need for numerous assumptions and hardly accessible data.

Optimized Fabrication Process and PD Characteristics of MVDC Multilayer Insulation Cable Systems for Next Generation Wide-Body All-Electric Aircraft

For wide-body all-electric aircraft (AEA), a high-power-delivery, low-system-mass electric power system (EPS) necessitates advanced cable technologies. Increasing voltage levels enhances power density yet poses challenges in aircraft cable design, including managing arc-related risks, partial discharges (PDs), and thermal management. Developing multilayer multifunctional electrical insulation (MMEI) systems for aircraft applications is a feasible option to tackle these challenges and reduce the size and mass of cable systems. This approach involves selecting layers of different materials to address specific challenges. Our prior research concentrated on the modeling and simulation-based design of MMEI systems for MVDC power cables. Experimental tests are essential for determining the behavior of PDs under varying pressure conditions. Also, the dielectric strength and time to failure of the designs need to be assessed. In this work, the fabrication process of a down-selected MMEI flat configuration is discussed and analyzed. This paper analyzes the fabrication process of power cables employing MMEI configurations and evaluates the PD characteristics of down-selected ARC-SC-T-MMEI cable samples. This study presents a detailed analysis of the characteristics of PD under atmospheric and low-pressure conditions, which will provide essential insights into the design of MVDC cables for future AEA applications.

Study on the Influence of a Powered Nacelle on the Wake Vortex Characteristics of Wide-Body Aircraft

The aircraft wake vortex is an important factor affecting flight safety; as an important part of the aircraft, the powered nacelle will inevitably have an important impact on the aircraft wake vortex, so it is of great practical significance to research it. The present study focused on the numerical simulation of the wake flow of large aircraft (as the front aircraft) and the comparative analysis of the influence of engine jets on the wake flow. In order to meet the accuracy requirements and control the consumption of computing resources, LES and RANS methods were compared, and the RANS method was finally selected for subsequent calculation. The dynamic effect of jet flow was simulated by simplifying the boundary conditions of the inlet fan and outlet bypass as the mass flow boundary condition. The simulation results showed that the engine nacelle will have a significant impact on the morphology of the aircraft wake flow (position and strength of the main vortex in the wake flow system), which is caused by the vortices formed under the shear flow and separated flow of the nacelle. However, the nacelle will not significantly change the total strength of the wake vortex (half-plane circulation). The engine jet intensity causes additional turbulent mixing, which will accelerate the fusion of the nacelle vortex and ultimately change the intensity ratio of the inner wing vortex and the wingtip vortex, affecting the trajectory of the wake of the mean vortex. The study provides a corresponding reference for the following research on a wake vortex by a powered nacelle.

A method determining critical operating parameters for landing aircraft based on runway pavement skid resistance

ABSTRACT Poor skid resistance of airport pavement is the critical cause of runway excursion accidents. While the current determination methods of skid resistance are limited to the independent operating parameters and the discontinuously monitoring the skid resistance, the empirically calculating critical operating parameters. In this study, an aircraft tire-fluid-airport pavement skid resistance model was developed using numerical simulation technology. The wide-body aircraft B777 was taken as an example, the available skid number (SN) was used to continuously track the skid resistance of pavement under various landing conditions. The combined effects of groove type, water film thickness and landing weight on the pavement skid resistance performance were evaluated when the pavement reached the maintenance threshold state. Results show that the skid resistance of the ungrooved pavement was subpar according to FAA. The skid resistance was positively connected with the grooved size and landing weight but negatively correlated with the water film thickness. Under certain operating conditions, the FAA maintenance threshold groove still meets the requirements for aircraft landing safety throughout the whole range of landing speeds. A real-time determination method of pavement skid resistance was proposed. It can guide pavement maintenance management departments to avoid runway excursion accidents.

Tyre heat of multi-wheel bogie undercarriage at touchdown

AbstractAlmost all studies on tyre heat during aircraft touchdown are based on the assumption that the tyres touch the ground simultaneously, and the aircraft’s load is evenly distributed among each tyre. However, the unique design of multi-wheel bogie undercarriage on wide-body aircraft gives the tyres a specific touchdown sequence. The friction, heat, and thermal wear they face are entirely different. Therefore, this study establishes a model to simulate the dynamics of the multi-wheel bogie undercarriage and relies on Laplace’s equation to calculate the treads’ heat generation and temperature rise. The innovative three-dimensional tread temperature display method can further determine the tyre’s thermal wear. It is found that faster landing increases tyre heat by extending the friction time and distance for all tyres. Softer landing increases the independent rotation time of the early-touched tyres, thus significantly raising the tread temperature due to high frictional power density around the tread centreline areas.

Stochastic Modelling of Aircraft Ground Time at Soekarno-Hatta International Airport

Ground time plays an important role in keeping flight on-time performance and passenger smooth flow. It varies depending on the aircraft type, procedures, passenger number and/or cargo amount, maintenance requirements, and ground handling service quality. This research aims to explore the ground time distribution pattern at Soekarno-Hatta International Airport. The daily flight historical data is divided into several categories based on the airline’s service type for local airlines, the airline’s origin for foreign airlines, the type of flight, and aircraft size. Ground time data of each flight category is then fitted to all possible distribution types by using the Distribution Fitting app in Matlab. The best-fitted distribution definition uses the Kolmogorov-Smirnov test by comparing the p-value of each distribution. 6 distributions fit 20 flight categories. Almost all local airlines’ ground time except full-service carrier international flights and low-cost carrier international flights with wide-body aircraft fit to Burr distribution. Full-service carrier international flight with narrow and wide-body aircraft, international flight with narrow-body aircraft operated by airlines from China and other countries fit Generalized Extreme Value distribution. Low-cost carrier international flights with wide-body aircraft and private flights fit to Inverse Gaussian distribution. International flights with wide-body aircraft operated by airlines from Korea, Japan, and other countries airlines fit for Nakagami distribution. While the cargo flights fit t Location-Scale distribution for wide-body aircraft and Weibull distribution for narrow-body aircraft. Then the stochastic models are developed based on each flight category’s distribution parameters. These models are expected to be able to guide future research in ground time or apron capacity management as they provide the data distribution without more primary data needed.

Study of Partial Discharge Characteristics of Optimally Fabricated MMEI Flat Samples Under DC and Their DC Dielectric Strength for Applications in Envisaged All-Electric Wide-Body Aircraft

Study of Partial Discharge Characteristics of Optimally Fabricated MMEI Flat Samples Under DC and Their DC Dielectric Strength for Applications in Envisaged All-Electric Wide-Body Aircraft

Defect Detection Image Processing for Drone Inspection on Wide-Body Aircraft Surface

The dependence on Unmanned Aerial Vehicles (UAVs) has greatly increased in many sectors around the globe. UAVs are in high demand and their technology is developing quickly, due to their ability to handle a variety of issues in a sophisticated manner. UAVs deployment in the aviation industry is still in the trial phase, thus certain adjustments must be made to make sure the UAVs meet safety standards. Safety is the most important factor in the aviation sector since it involves people’s lives. UAVs are required to make the maintenance of an aircraft more efficient. For instance, UAVs are capable of replacing the labor-intensive inspection procedure with conducive and safe regulation. Additional tools or sensors need to be added to the UAVs system to ensure the objective of applying UAVs is achieved. The camera mounted on the drone is able to enhance the functionality and widen the range of applications of UAVs. This thesis presents the UAV system that is able to assist during an aircraft inspection. The camera mounted on the drone is installed with an image processing program to identify the defect caused by a lightning strike.

Flight Dynamic Characteristics of Wide-Body Aircraft with Wind Gust and Turbulence

In this research, a wide-body aircraft was analyzed with critical monitoring of its states, a function of several control inputs (wind gust, turbulence, and microburst). The aerodynamic and stability coefficients of a Boeing 747-200 were obtained from previously published works and 6- DOF equations were formulated. Simulations were conducted for various control inputs to determine the aircraft’s free response, as well as the forced response. In order to understand the nature of the atmosphere, three different models were incorporated, including (i) the Dryden Model, (ii) wind gust, and (iii) microburst. The aircraft was found to be stable in the longitudinal and lateral flight modes, with trim conditions agreeing with published data. For a vertical wind gust of −10 ft/s, the AoA and pitch rate were observed to oscillate sinusoidally and became stable with new trim conditions. These states were found to regain trim conditions once the gust was removed. In the case of 3D gust, it was found that the longitudinal modes achieved a new trim condition through Phugoid oscillations, whereas the lateral modes underwent short-period oscillations. For the case of turbulence, random fluctuations were observed for trim conditions with no unstable behavior. When considering the microburst case, it was found that the aircraft initially gained altitude in the region of the headwind; this was followed by a sharp descent under the influence of a vertical velocity component.

A comparative analysis of potential aerosol exposure in a wide-body aircraft cabin using tracer gas and fluorescent particles

We compare two aerosol surrogate tracers in aircraft cabins for breathing and coughing sources: tracer gas collected in the ACER Boeing 767 mock-up and fluorescent particles collected in an actual Boeing 767 aircraft by the US Transportation Command (TRANSCOM). Each source was located individually in window and middle seats. Exposure generally decreased with source distance. A window seat breathing source resulted in good agreement between datasets for exposure (as percent of release) for the TRANSCOM hangar-AFT testing mode, which corresponds to the 11-row cabin ACER laboratory space. Average tracer gas exposure for a middle seat breathing source was higher in the ACER study than the fluorescent particle tracer exposure in the TRANSCOM study. Using a coughing source in a window seat, the exposure for the TRANSCOM data was higher within the first two rows from the source before decreasing to and tracking with the ACER levels, until increasing after about 5 m away. A similar trend was recorded for a middle seat coughing source with higher overall exposure for the TRANSCOM data. Sources of exposure variation between the studies include particle deposition. This work helps optimize aerosol dispersion research in aircraft cabins and provides some validation to the existing studies.

The Critical Threshold of The Relationship Between Take-Off Load And Powertrain Load of the Aircraft

The critical threshold of the relationship between take-off load and powertrain load of the aircraft has long intrigued researchers and posed significant challenges. Delving into this subject, extensive research has been conducted to comprehend the intricate dynamics between these two variables. This thesis aims to contribute to this ongoing investigation by analyzing and drawing conclusions based on observed load variations and their impact on power system functionality. The study encompasses a comprehensive examination of various aircraft types, ranging from ultralight aircraft to wide-bodied aircraft and Unmanned Aerial Vehicles (UAVs). Each aircraft category presents unique characteristics and demands distinct engine requirements, further complicating understanding the take-off load to powertrain load relationship. By meticulously studying the changes in loads during the crucial take-off phase, this research aims to uncover valuable insights into the essentiality of an efficient power system. The findings of this study have the potential to enhance aircraft design and operations, ultimately leading to safer and more optimized flight experiences.

Performance optimization design of wide-body aircraft pressure refueling system

In order to reduce the wide body aircraft refueling process time-cost and improve the airport operation efficiency, pressure refueling system design strategy was innovated. The shutoff valves’ operation sequence in refueling process was optimized. The diameter of the orifices on the pressure refueling system fuel line was designed. Pressure refueling performance was simulated and analyzed at different scenarios. The results show that it can improve the pressure refueling system performance at different scenarios by optimizing the pressure refueling process strategy design including optimizing the fuel line orifice design and optimizing the wing tank inner side shut-off valve operation sequence.

Wide-body aircraft fuel jettison system design and analysis

In order to design the highly integrated fuel jettison system, the hydrodynamic performance design flow chart for the highly integrated fuel system has been proposed, and the 1-D fuel line network performance model has been developed. An innovative fuel jettison system for wide-body aircraft has been designed. The system performance has been simulated and analyzed. The results show that the proposed flow chart can be used for the highly integrated fuel system design, and the fuel jettison performance requirements can be met. The system parameters including the wing tank main pump characteristic, the flow area of the orifice set in the fuel line connecting the feeding line and the refueling line, and the flight height have significant effects on the fuel jettison performance. Besides, the aircraft total fuel jettison performance is also affected by the central tank override pump characteristic, the engine fuel consumption, and the flow resistance of fuel line network.

Design of High Power Density MVDC Cables for Wide-Body All Electric Aircraft

Aircraft electrification yields the next generation of aircraft such as more electric aircraft (MEA) and all electric aircraft (AEA). These aircraft require high-power-density and low-system-mass electric power systems (EPS). To this end, the voltage of the system must be enhanced to reach medium voltage levels in a few kV ranges. However, using medium voltage (MV) EPS for aircraft exacerbates the challenges of designing aircraft cables such as arc and arc tracking, partial discharges (PD), and thermal management. In this paper, several novel multi-layer based insulation systems for MVDC power cables are proposed to resolve aircraft cables’ challenges while maintaining low weight and size. The proposed cables are thermally and electrically analyzed and compared to cable systems designed based on IEC60502 and AS50881 standards. We use a coupled electrical-thermal-fluid flow dynamic model, for simulations where all possible heat transfer approaches, including conduction, convection, and radiation, to transfer mainly the joule heating generated in the core conductor to ambient with a low pressure of 18.8 kPa which is the air pressure at cruising height of wide-body aircraft (12.2 km) are considered and modeled. To compare the proposed cables to the designs based on IEC 60502 and AS50881, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i> is introduced, which is the product of cables’ overall mass in a unit length and diameter. The results show that besides benefiting multi-layer, multi-function insulation systems to resolve aircraft cables’ challenges, the overall diameter and weight of the designed cables are lower than single-layer insulation system designs based on AS50881 and IEC60502.

Digital twin for Electronic Centralized Aircraft Monitoring by machine learning algorithms

Electronic Centralized Aircraft Monitoring (ECAM) parameters play a vital role in the operation of an aircraft to reduce the workload of the cockpit crew. A wide-body commercial aircraft with a triple-spool turbofan engine is examined within the scope of the study. This study is focused on the estimation of the ECAM primary engine parameters: Engine Pressure Ratio, Exhaust Gas Temperature, Fuel Flow, and Shaft Speeds without any additional measurement for data continuity. The recorded flight data obtained from a commercial aircraft is processed with machine learning methods, and the most suitable estimation method is tried to be determined. Correlation analysis is carried out for each data in the study to show strong predictor candidates. The modeling process is conducted by using MATLAB. Results indicate that the Fine Decision Tree is better at memorizing data, while the Wide Neural Network is better at generalizing data. Computational results show that the developed models are outstandingly precise and accurate to estimate aircraft's ECAM data to ensure flight safety for health and performance monitoring of an engine. Thus, when an unreliable situation occurs while performing the flight in practical conditions, the cockpit crew will be able to overcome this situation by Digital Twin.

Design optimization to minimize wake of wide-body transport aircraft

A cutting-edge sustainable airplane can improve performance and enhance profitability are the most significant future concerns for the aviation industry. This research aims to analyse and assess aircraft performance of mid-size transport aircraft through retrofit designs. An optimal design was employed using a non-linear optimization approach under two cases fuselage alone (case 1) and a combination of fuselage-wing-empennage (case 2). These two retrofit concepts were evaluated and compared with the baseline A310–200 aircraft. To compute the objective function for various cases, non-linear solver was used from MATLAB optimization tool box. Additionally, the parametric studies of aerodynamics, structural and operational performance analysis are carried out by using Advanced Aircraft Analysis (AAA) 5.0 software. Sensitivity analyses are performed to assess the overall effectiveness of the optimal design. The key findings of this paper obtained the following parameters as Maximum take-off Weight, empty weight, fuel weight, parasite drag coefficient, rate of climb, take-off distance and landing distance are improved by 0.36%, 26.02%, 10.12%, 4.48%, 27.24%, 13.13% and 9.2% respectively. At the end, the paper provides a clear statement on the managerial perceptions and future insights for the upcoming challenges towards sustainable design.