Aircraft Performance Analysis Research Articles

An aircraft assembly process formalism and verification method based on semantic modeling and MBSE

The aircraft assembly system is highly complex involving different stakeholders from multiple domains. The design of such a system requires comprehensive consideration of various industrial scenarios aiming to optimize key performance indicators. Traditional design methods heavily rely on domain expert knowledge using documents to define assembly solutions which are later verified through simulations. However, these document-centric approaches cannot provide graphical notations for engineers to efficiently understand the entire assembly process. Moreover, it is difficult to analyze the performance of the designed assembly processes using simulations since the simulation models have to be developed based on the documents manually rather than be generated automatically from the design models. In this paper, a semantic-driven approach is proposed to support aircraft assembly process formalism and performance analysis. First, meta-models of aircraft assembly processes are developed based on SysML and discrete-event simulation models using a semantic modeling language named KARMA. Then an application ontology is defined for generating semantic models from KARMA architecture models to capture domain knowledge, system requirements and simulation model information of the aircraft assembly process. A model transformer is developed to transform the KARMA models to discrete-event simulation models based on the application ontology. Then the generated simulation models are executed to obtain the simulation results for verifying the designed assembly process. Finally, the obtained simulation results are used to support decision-making of selecting the optimal aircraft assembly process. A case study is conducted to verify the proposed method.

Impact of Figures of Merit Selection on Hybrid–Electric Regional Aircraft Design and Performance Analysis

The adoption of hybrid–electric propulsion, allowing us to partially replace fuel with batteries and to reduce aircraft in-flight emissions, represents one of the main investigated solutions to mitigate the aviation climate impact. Despite its environmental potential being appealing for a practical application, two main drawbacks limit the actual implementation of this technology: first, the low gravimetric energy density of the batteries restricts hybrid–electric aircraft payload and range capabilities; second, the production of electricity is currently not entirely based on renewable energy sources, hence a non-direct emissions budget may limit the benefit in terms of overall decarbonization. When designing hybrid–electric aircraft, even projecting its actual entry into service in the next decades, it is necessary to take these limitations into account depending on both the more reliable technological forecasts on the development of electric components and on the estimates of electricity production. A proper analysis of the figure of merits related to the operation of such an aircraft, therefore, becomes crucial in assessing the impact related to its introduction into service. In this context, trade-offs between different performance metrics may be needed to efficiently exploit the environmental benefits of such an advanced concept, while limiting the possible drawbacks coming from its utilisation. This paper provides a performance analysis of hybrid–electric aircraft through an assessment of the relevant figures of merit characterizing its operations. In particular, direct and non-direct emissions, climate impact, ground pollution, operating costs, fuel consumption, weight, and a combination of these figures of merit allow us to define a proper development perimeter in which a possible (future) hybrid–electric aircraft can express its maximum potential towards all the aspects of its utilisation. The trade-off analyses provided in this paper allow us to identify more effective paths for the actual development of hybrid–electric aircraft, highlighting the impact of the selected design variables on the performance metrics, and bringing to light also the possible related limitations.

Multidisciplinary Design Optimization of Transonic Wings with Boundary-Layer Suction

A quasi-three-dimensional aerodynamic solver is developed for the aerodynamic analysis of wings in a transonic regime that is able to capture the effect of BLS in hybrid laminar flow control (HLFC) application or transition to turbulent flow for natural laminar flow (NLF). The tool provides accurate results, but without the high computational cost of high-fidelity tools. The solver combines the use of an Euler flow solver characterized by an integral boundary-layer method and linear stability analysis using a approximation for transition prediction. In particular, a conical transformation is adopted, including the determination of the shock-wave position. The solver is implemented in a multidisciplinary design optimization (MDO) framework, including wing weight estimation and aircraft performance analysis. The framework consists of different modules: aerodynamics, structure, suction system analysis, and performance evaluation. Using a genetic algorithm and considering HLFC technology, wing MDO has been performed to find the optimum wing planform and airfoil shape. A backward-swept wing (BSW) aircraft, developed inside the Cluster of Excellence–Sustainable and Energy Efficient Aviation (A) is studied. Novel technologies such as active flow control, limited maximum load factors due to load alleviation, and novel materials allow a fuel weight reduction of 6%.

A simulation model for the electrical rotary-wing aircraft (eVTOL) performance estimation for the urban air mobility purposes

The present paper presents a simulation model description developed for the aircraft performance estimation of the most popular electric vertical takeoff and landing aircraft (eVTOL) aerodynamic configurations with the electric (hybrid) power plant for the urban air mobility purposes. It focuses on the quadcopter-type eVTOL aircraft aerodynamic configurations using the unshrouded-propellers or ducted fans driven by electric motors. The aircraft performance analysis for aerodynamic configurations of the quadcopter and tilt rotor-quadcopters with the tilt rotors and wing with the all-electric (EP) or hybrid power plant (HP) is given. To compare aircraft performance, the estimation results for a conventional single-rotor helicopter with EP or HP are given. Based on the numerical solution equation of the aircraft existence, feasible structural components mass distributions for various types of eVTOL configurations were obtained. eVTOL aircraft performance, including the estimation of apparent and drag power for the airspeed range, from hovering to the maximum airspeed, as well as for the transition modes (tilt rotor aircraft and quadcopters) were estimated. The eVTOL aircraft flight range and duration with EP and HP at the straight and level flight mode were calculated. Specific mass characteristics of EP and HP components (batteries, generators, electric motors, etc.) to ensure acceptable eVTOL aircraft performance were identified. A comparative evaluation of considered eVTOL configurations for the purpose of their efficiency was performed. Aerodynamic calculations were carried out based on the known analytical techniques of the lifting propeller momentum theory with the data correction capability according to test results. The simulation model, obtained in this paper, can be considered in the phase of the preliminary choice as the first approach of structural parameters and aerodynamic configurations of prospective electric (hybrid) eVTOLs designed for the use as an urban air taxi.

Trend in tropopause warming and its influence aircraft performance

PurposeTemperature anomalies in the upper troposphere have become a reality as a result of global warming, which has a noticeable impact on aircraft performance. The purpose of this study is to investigate the total air temperature (TAT) anomaly observed during the cruise level and its impact on engine parameter variations.Design/methodology/approachEmpirical methodology is used in this study, and it is based on measurements and observations of anomalous phenomena on the tropopause. The primary data were taken from the Boeing 747-8F's enhanced flight data recorder, which refers to the quantitative method, while the qualitative method is based on a literature review and interviews. The GEnx Integrated Vehicle Health Management system was used for the study's evaluation of engine performance to support the complete range of operational priorities throughout the entire engine lifecycle.FindingsThe study's findings indicate that TAT and SAT anomalies, which occur between 270- and 320-feet flight level, have a substantial impact on aircraft performance at cruise altitude and, as a result, on engine parameters, specifically an increase in fuel consumption and engine exhaust gas temperature values. The TAT and Ram Rise anomalies were the focus of the atmospheric deviations, which were assessed as major departures from the International Civil Aviation Organizations–defined International Standard Atmosphere, which is obvious on a positive tendency and so goes against the norms.Research limitations/implicationsNecessary fixed flight parameters gathered from the aircraft's enhanced airborne flight recorder (EAFR) via Aeronautical Radio Incorporated (ARINC) 664 Part 7 at a certain velocity and altitude interfacing with the diagnostic program direct parameter display (DPD), allow for analysis of aircraft performance in a real-time frame. Thus, processed data transmits to the ground maintenance infrastructure for future evaluation and for proper maintenance solutions.Originality/valueA real-time analysis of aircraft performance is possible using the diagnostic program DPD in conjunction with necessary fixed flight parameters obtained from the aircraft's EAFR via ARINC 664 Part 7 at a specific speed and altitude. Thus, processed data is transmitted to the ground infrastructure for maintenance to be evaluated in the future and to find the best maintenance fixes.

Analiza performansi i kinematike kretanja bespilotnih vazduhoplova

The use of drones today has become an integral part of modern life to the extent that the level of drone utilization determines the quality of life. The expansion of drone applications has grown exponentially. This growth is primarily due to their low acquisition and maintenance costs, as well as their versatility. First of all, their expansion is contributed by the low costs of both acquisition and maintenance, as well as the possibility of various applications. The paper aims to present drones and their advantages compared to traditional aircraft as a means of transportation. The paper includes an analysis of unmanned aircraft performance, an examination of the kinematics of unmanned aircraft movement, a discussion of the most common structure used in unmanned aircraft (the quadcopter), and a comprehensive assessment of the risks associated with unmanned aircraft and their potential integration into civil air traffic. The quadcopter structure, as the dominant solution for the production of unmanned aircraft, is discussed in detail. At the very end, an overall analysis of the risks posed by unmanned aircraft and, as such, whether they can be integrated into civil air traffic is given.

Initial weight estimation of twin-fuselage configuration in aircraft conceptual design

The Ultra-High Aspect Ratio Wing (UHARW) concept can improve the aircraft’s aerodynamic efficiency and reduce fuel consumption. The Twin-Fuselage (TF) configuration is one of the promising concepts for the UHARW design to reduce the wing bending moments and shear forces. This paper presents the development of a semi-empirical method for the weight estimation of TF aircraft in the initial sizing stage. A physics-based wing weight estimation method is improved for higher fidelity aerodynamic analysis and modified for composite material structures of TF aircraft. This method is used in the design of experiments and the results are applied for regression analysis to establish a semi-empirical method. Eventually, the established semi-empirical weight estimation method is integrated into a TF aircraft conceptual design and performance analysis framework. A mid-range TF aircraft and a long-range TF aircraft are designed and sized to illustrate its application and efficiency in rapidly estimating the TF aircraft weight breakdown.

Метричні системи оцінки ефективності та масштабованості паралельних обчислень

"The current state of development of computer technology allows you to build parallel computer systems that use almost unlimited number of processors. The availability of such systems has aroused interest in studying the performance of parallel computers, which contain a large number of processors, in the implementation of real multidimensional problems. One way to increase the efficiency of parallel architectures is to reduce the time required to perform a time-consuming task, which should be commensurate with the number of processing resources used to solve this problem. The second direction is the development of highly scalable parallel or parallel algorithms. Under the scalability of the parallel algorithm on the parallel architecture we will consider a measure of its ability to efficiently use a growing number of processors. Scalability analysis can be used to select the best combination of algorithm architecture for a problem with different constraints on the size of the problem and the number of processors. It can be used to predict the performance of a parallel algorithm and a parallel architecture for a large number of processors based on known performance on a smaller number of processors. For a fixed size of the problem, it can be used to determine the optimal number of processors, which will be used and the maximum possible acceleration that can be obtained. Scalability analysis can also predict the impact of changes in hardware technology on performance and thus help develop the best parallel architectures to solve different problems The aim of the work is to critically evaluate the state of modern theory of analysis of aircraft performance and scalability and to demonstrate further research on the development of new and more complex analytical tools to analyze the effective use of the benefits of parallel equipment. The main task of the study is to develop new and modify existing theoretical models, methods and formalisms to study the problems of efficiency and scalability of parallel computing. Mathematically, to simplify the analysis, it is assumed that all temporal characteristics are non-negative. This means that acceleration is always limited by the number of processors, p, and efficiency - by one. For example, acceleration can be super-linear, overhead can be negative if memory is hierarchical and access time is increased discretely by increasing the memory used by the program. In this case, the effective computing speed of a large program will be slower on a serial processor than on a parallel computer with similar processors."

Development of Unified High-Fidelity Flight Dynamic Modeling Technique for Unmanned Compound Aircraft

This study presents the unified high-fidelity flight dynamic modeling technique for compound aircraft. The existing flight dynamic modeling technique is absolutely depended on the experimental data measured by wind tunnel. It means that the existing flight dynamic model cannot be used for analyzing a new configuration aircraft. The flight dynamic modeling has to be implemented when a performance analysis has to be performed for new type aircraft. This technique is not effective for analyzing the performance of the new configuration aircraft because the shapes of compound aircraft are very various. The unified high-fidelity flight dynamic modeling technique is developed in this study to overcome the limitation of the existing modeling technique. First, the unified rotor and wing models are developed to calculate the aerodynamic forces generated by rotors and wings. The revolutions per minute (RPM) and pitch change with rotation direction are addressed by rotor models. The unified wing model calculates the induced velocity by using the vortex lattice method (VLM) and the Biot–Savart law. The aerodynamic forces and moments for wings and rotors are computed by strip theory in each model. Second, the performance analysis such as propeller performance and trim for compound aircraft is implemented to check the accuracy between the proposed modeling technique and the helicopter trim, linearization, and simulation (HETLAS) program which is validated. It is judged that this study raises the efficiency of aircraft performance analysis and the airworthiness evaluation.

Flight performance analysis with data-driven mission parameterization: mapping flight operational data to aircraft performance analysis

This paper develops a hybrid data-driven physics-based model, which maps flight operational data to aircraft performance analysis, in order to estimate aircraft fuel consumption and flight condition information. The hybrid model is an adaptation of the enhanced high-fidelity flight performance analysis, with adjustments made for mission parameters. Through the proposed mission parameterization process, nominal parameters are substituted by the extracted mission and speed profiles. In other words, real flight operations are integrated into the physics-based analysis. The versatility of the hybrid model is demonstrated in three cases (short-, medium-, and long-haul flight sectors), which have very different characteristics. It is also validated against the corresponding fuel consumption data from an airline (with root mean square errors less than 3%) and shows great improvements relative to the pure physics-based model.

Digitalization of aircraft performance nomograms

PurposeThe purpose of this paper is to develop a new tool for aircraft performance analysis and optimization.Design/methodology/approachIn this paper, the methodology of converting nomogram curves into mathematical functions is presented. Aircraft performance nomograms represent graphical interpretation of influence of several variables on performance such as environmental conditions, runway conditions and aircraft mass. The aircraft performance nomograms are converted in mathematical functions that describe several independent variables’ influence on aircraft performance parameters. To achieve greater accuracy in calculation of aircraft performance parameters, it is necessary to determine mathematical functions presented by dependent variable variations with several independent variables. The method of determining mathematical functions is illustrated on Fokker 100 landing gear extended net climb gradient determination graph.FindingsTo evaluate model, it was necessary to determine net climb gradient both graphically and analytically using model and compare the results. After solving both analytically and graphically, it was concluded that results are a match. During model evaluation, it was observed that model has a lot of advantages such as it has great precision of calculation, requires less time to calculate results and has minimum error possibility.Practical implicationsFinal result of digitalization of aircraft performance nomograms is software production. The usage of this software can reduce flight planning and aircraft exploitation costs in several different manners. Airliners can produce such a software for those types of aircraft where there is no software provided from aircraft manufacturer.Originality/valueDigitalization of aircraft performance nomogram has never been analyzed before, although there is a possibility of this particular methodology implementation in a practical manner in aviation industry.

Advanced aircraft performance analysis

PurposeThe preliminary aircraft design process comprises multiple disciplines. During performance analysis, parameters of the design mission have to be optimized. Mission performance optimization is often challenging, especially for complex mission profiles (e.g. for unmanned aerial vehicles [UAVs]) or hybrid-electric propulsion. Therefore, the purpose of this study is to find a methodology that supports aircraft performance analysis and that is applicable to complex profiles and to novel designs.Design/methodology/approachAs its core element, the developed method uses a computationally efficient C++ software “Aircraft Performance Program” (APP), which performs a segment-based mission computation. APP performs a time integration of the equations of motion of a point mass in the vertical plane. APP is called via a command line interface from a flexible scripting language (Python). On top of APP’s internal radius of action optimization, state-of-the-art optimization packages (SciPy) are used.FindingsThe application of the method to a conventional climb schedule shows that the definition of the top of climb has a significant influence on the resulting optimum. Application of the method to a complex UAV mission optimization, which included maximizing the radius of action, was successful. Low computation time enables to perform large parametric studies. This greatly improves the interpretation of the results.Research limitations/implicationsThe scope of the paper is limited to the methodology that allows for advanced performance analysis at the conceptual and preliminary design stages with an emphasis on novel propulsion concepts. The methodology is developed using existing, validated methods, and therefore, this paper does not contain comprehensive validation. Other disciplines, such as cost analysis, life-cycle assessment or market analysis, are not considered.Practical implicationsWith the proposed method, it is possible to obtain not only the desired optimum mission performance but also off-design performance of the investigated design. A thorough analysis of the mission performance provides insight into the design’s capabilities and shortcomings, ultimately aiding in obtaining a more efficient design.Originality/valueRecent developments in the area of hybrid or hybrid-electric propulsion systems have shown the need for performance computation tools aiding the related design process. The presented method is especially valuable when novel design concepts with complex mission profiles are investigated.

Experimental study of canard UAV aerodynamics

The present paper presents the aerodynamic characteristics of a canard fixed-wing unmanned aircraft TERES-02. A wind tunnel experiment is conducted using a specially designed model of the aircraft. The model is produced through the methods of rapid prototyping using a FDM 3D printer. Aerodynamic corrections are made and thorough analysis and discussion of the results is carried out. The obtained results can be used to determine the accuracy of numerical methods for analysis of aircraft performance.

Aircraft Performance Analysis in Conceptual Design Phase based on System-of-Systems Simulations

To obtain a competitive design in aircraft conceptual design phase, this paper propose an aircraft performance analysis method based on system-of-systems (SoS) simulations. The analysis process includes design space exploration and mission effectiveness analysis and the stochastic nature in SoS mission is captured based on a Monte Carlo method. Meanwhile as an example, the performance of UAVs which are applied in earthquake search and rescue SoS is analysed based on SoS simulations. The results show that the level of aircraft performance which leads to an optimum SoS effectiveness could be designed below the maximum performance. And it is necessary to apply SoS simulations into aircraft conceptual design phase to help designers optimize aircraft performance.

Conceptual investigation of a propulsive fuselage aircraft layout

Purpose – The purpose of this paper is the multi-disciplinary conceptual investigation of a propulsive fuselage (PF) aircraft layout allowing for new performance synergies through closely coupled propulsion/airframe integration. The discussed aircraft layout facilitates the ingestion of the fuselage boundary layer and the utilization of wake filling, thus eliminating a significant share of fuselage drag. Design/methodology/approach – Based on consistent book-keeping standards for conventionally installed and highly integrated propulsion systems, key aspects of conceptualisation regarding airframe and propulsion system are presented. As a result of this, a PF aircraft configuration is proposed featuring a fuselage fan power plant in conjunction with two under-wing podded power plants. Parametric models for integrated aircraft and propulsion system sizing and performance analysis are discussed that are suitable for the consistent mapping of the characteristics intrinsic to a PF layout. In an initial benchma...

Optimum number of engines for transport aircraft employing electrically powered distributed propulsion

Realizing a significant reduction of enroute emissions with respect to greenhouse gases is one major challenge in aircraft design today. Conventional kerosene propulsion systems are going to reach their efficiency limits in near future and it will be very ambitious to fulfill the requirements for future aircraft transportation using conventional engines. Consequently, new approaches for propulsion system design and integration are required to further improve aircraft efficiency through synergy effects. In this paper, a universally electric, short-haul, medium-capacity aircraft utilizing electric motors and battery for motive power is used as datum. The focus lies on the impact of a distributed propulsion system on the aircraft design and flight performance and will not discuss the advantages and disadvantages of the used reference aircraft configuration. Initial studies were performed identifying that the critical design cases for electric motor sizing are the one-engine-inoperative (OEI) flight segments, i.e., the climb gradients required at take-off and landing as well as field length requirements. By increasing the number of installed engines (i.e., motor–fan combinations) the OEI performance requirements may be satisfied with a reduced amount of installed motor and battery system power. An integrated aircraft performance analysis is conducted to estimate the possible net benefit in terms of increased aircraft range when increasing the number of installed engines. Aerodynamic efficiency degradation is considered as well as weight impacts due to electric motor scaling and necessary system architecture modifications. The analysis shows that a 6 % increase in aircraft design range can be achieved when going from 2 to 4 installed propulsive devices.

Rotor Interaction Noise in Counter-Rotating Propfan Propulsion Systems

Due to their inherent noise challenge and potential for significant reductions in fuel burn, counter-rotating propfans (CRPs) are currently being investigated as potential alternatives to high-bypass turbofan engines. This paper introduces an integrated noise and performance assessment methodology for advanced propfan powered aircraft configurations. The approach is based on first principles and combines a coupled aircraft and propulsion system mission and performance analysis tool with 3D unsteady, full-wheel CRP computational fluid dynamics computations and aeroacoustic simulations. Special emphasis is put on computing CRP noise due to interaction tones. The method is capable of dealing with parametric studies and exploring noise reduction technologies. An aircraft performance, weight and balance, and mission analysis was first conducted on a candidate CRP powered aircraft configuration. Guided by data available in the literature, a detailed aerodynamic design of a pusher CRP was carried out. Full-wheel unsteady 3D Reynolds-averaged Navier-Stokes (RANS) simulations were then used to determine the time varying blade surface pressures and unsteady flow features necessary to define the acoustic source terms. A frequency domain approach based on Goldstein’s formulation of the acoustic analogy for moving media and Hanson’s single rotor noise method was extended to counter-rotating configurations. The far field noise predictions were compared to measured data of a similar CRP configuration and demonstrated good agreement between the computed and measured interaction tones. The underlying noise mechanisms have previously been described in literature but, to the authors’ knowledge, this is the first time that the individual contributions of front-rotor wake interaction, aft-rotor upstream influence, hub-endwall secondary flows, and front-rotor tip-vortices to interaction tone noise are dissected and quantified. Based on this investigation, the CRP was redesigned for reduced noise incorporating a clipped rear-rotor and increased rotor-rotor spacing to reduce upstream influence, tip-vortex, and wake interaction effects. Maintaining the thrust and propulsive efficiency at takeoff conditions, the noise was calculated for both designs. At the interaction tone frequencies, the redesigned CRP demonstrated an average reduction of 7.25 dB in mean sound pressure level computed over the forward and aft polar angle arcs. On the engine/aircraft system level, the redesigned CRP demonstrated a reduction of 9.2 dB in effective perceived noise (EPNdB) and 8.6 EPNdB at the Federal Aviation Regulations (FAR) 36 flyover and sideline observer locations, respectively. The results suggest that advanced open rotor designs can possibly meet Stage 4 noise requirements.

Thrust and Drag Models for Performance Calculations for High-Speed Aircraft

On the introductory level, aircraft performance analysis usually assumes that the thrust and the drag polar parameters are independent of Mach number. To perform analyses of high-speed aircraft, however, Mach number effects have to be included. This study describes models of thrust and drag that include Mach number effects and the application of these models to analyses of cruise speed, ceiling, and range, as well as to performance predictions that use energy methods.

Potential Impacts of Very Light Jets in the National Airspace System

Very light jets constitute a class of three to eight passenger turbofan-powered aircraft that will enter service in 2006 and will need to be integrated into the National Airspace System. An aircraft performance analysis showed similarities between the predicted performance and capabilities of very light jets and the performance of existing light jets. Based on this, an analysis of operating patterns of existing light jets was used to predict how very light jets will be operated. Using 396 days of traffic data from the FAA enhanced traffic management system, the operating patterns of existing light jets were analyzed. It was found that 64% of all the flights flown by lightjets had their origin, destination, or both within the top 23 regional airport systems in the continental United States. This concentration of light jet traffic was found in areas of the air transportation system that are currently exhibiting dense traffic and capacity constraints. The structure of the network of routes flown by existing light jets was also studied and a model of network growth was developed. It is anticipated that this concentration will persist with emerging very light jet traffic. This concentration of traffic at key areas in the system will have implications for air traffic control management and airport activity. For regional airport systems, core airports are expected to saturate and, reliever airports will become critical for accommodating traffic demand. The entry of very light jets will increase the traffic load at the terminal airspace: terminal radar approach control. These impacts need to be taken into account to allow a successful integration of these aircraft in the National Airspace System.

Noise impact study of a new 2004 noise abatement procedure at the Louisville airport

A flight demonstration test in September 2004 at Louisville was a continuation of research conducted in 2002 by a team sponsored by the Federal Aviation Administration’s Center of Excellence for Air Traffic Systems. A continuous descent procedure was designed primarily to minimize environmental impacts such as community noise and aircraft emissions, and to maximize savings in fuel and flight time. The test was designed to show the operational suitability of the new area navigation arrival procedure that begins at cruise altitude and which may be used in daily operation on two opposite facing runways. Flyover noise measurements were taken during a two‐week testing period, and a three‐week baseline period. The latest research focused on detailed analysis of aircraft performance, collecting noise data and noise prediction. The noise measurements confirm increased repeatability and predictability of noise levels that resulted from the well‐designed procedure. The Integrated Noise Model was used to compare noise levels of test and baseline flights. And noise predictions using precise flight data confirm that a continuous descent approach reduces noise levels by 4 to 6 decibels which in turn reduces contour area by as much as 30 percent.