Purpose – The present study aimed to demonstrate different computational models, data and stability results obtained in a wide number of projects of various aircrafts such as unmanned aerial vehicles (UAVs), general aviation and big passenger flying airliners in blended wing body (BWB) configurations. Many details of modeling and computing are shown for unconventional configurations, namely, for a BWB aircraft and for tailless UAVs. Design/methodology/approach – Mathematical models for analysis of static and dynamic stability were built and investigated based on equations of motion in the linearized form using the so-called state variable model for a steady-state disturbed, generally asymmetric, flight. Findings – Flight dynamics models and associated computational procedures appeared to be useful, both in a preliminary design phase and during the final assessment of the configuration at flight tests. It was also found that the difference between thresholds for static and dynamic stability conditions was equal to 9 per cent of mean aerodynamic chord (MAC) in the case of BWB and 3 per cent of MAC in the case of tailless UAVs. Practical implications – Many useful information about aircraft dynamics can be easily obtained from computational analyses including time to half/double and periods of oscillation, undamped frequencies, damping ratio and many others. Stability analysis of different unconventional configurations will be easier and faster if an access to such configurations is available. Originality/value – This paper presents a very efficient method of assessment of the designing parameters, especially in an early stage of the design process. In open literature, there are a great number of datasets for classical configurations, but it is hard to find anything for passenger BWB and tailless UAVs. Stability computations are performed based on equations of motion derived in the stability frame of the reference fixed with one-quarter of MAC. It can be considered as an original, not typical but a very practical approach because values of stability and control derivatives do not change even if the centre of gravity is travelling.
Key results from the EU H2020 project CENTRELINE are presented. The research activities undertaken to demonstrate the proof of concept (technology readiness level—TRL 3) for the so-called propulsive fuselage concept (PFC) for fuselage wake-filling propulsion integration are discussed. The technology application case in the wide-body market segment is motivated. The developed performance bookkeeping scheme for fuselage boundary layer ingestion (BLI) propulsion integration is reviewed. The results of the 2D aerodynamic shape optimization for the bare PFC configuration are presented. Key findings from the high-fidelity aero-numerical simulation and aerodynamic validation testing, i.e., the overall aircraft wind tunnel and the BLI fan rig test campaigns, are discussed. The design results for the architectural concept, systems integration and electric machinery pre-design for the fuselage fan turbo-electric power train are summarized. The design and performance implications on the main power plants are analyzed. Conceptual design solutions for the mechanical and aero-structural integration of the BLI propulsive device are introduced. Key heuristics deduced for PFC conceptual aircraft design are presented. Assessments of fuel burn, NOx emissions, and noise are presented for the PFC aircraft and benchmarked against advanced conventional technology for an entry-into-service in 2035. The PFC design mission fuel benefit based on 2D optimized PFC aero-shaping is 4.7%.
Purpose -This study seeks to present the initial requirements for medium altitude long endurance (MALE) UAV design of an increased reliability. Design/methodology/approach -Shows and describes the successive design phases of PW-103 MALE UAV. Findings -The analysis of the performances of the PW-103 UAV, powered by either a main or an auxiliary engine, demonstrated that auxiliary power unit improved flight safety significantly. Originality/value -Successive MALE UAV configurations developed in the design process were aerodynamically more efficient than their predecessors.
PurposeTo provide an effective numerical method for analysis and design of aerodynamic characteristics of unmanned aerial vehicles basing on commercial package VSAERO.Design/methodology/approachCalculation was made by VSAERO package, which is based on a classical panel method enhanced on boundary layer method. Paper explains how to use efficiently VSAERO package, which utilizes advanced CAD techniques, in modern designing of unmanned aircraft.FindingsDuring aerodynamic analysis of unmanned aircraft the computing cycle is repeated many times until the required accuracy is obtained and when the best performance of an aircraft is achieved. Design process depends on the number of iterations. If the preliminary configuration (the so‐called starting design point) is well selected and the aerodynamic analysis is completed in a relatively short time, then the overall design time will be shortened.Research limitations/implicationsThe panel method is very useful tool in spite of different limitations. For example, the Reynolds number has to be sufficiently high, angles of attack and sideslip have to be small enough. Computational process is relatively fast and the accuracy depends on the geometry representation. The boundary layer included into the computational model improves the accuracy of aerodynamic calculations. This methodology is limited to subsonic and low transonic speeds.Practical implicationsA very useful source of computational information and patterns to follow, especially for engineering students and engineers dealing with aerodynamic of unmanned aviation. Surface panel geometry can be transferred from UNIGRAPHICS via IGES files or can be generated from scratch using SPING or PEP software.Originality/valueThis paper offers a practical help for designers planning to develop a new unmanned platform. VSAERO package appeared to be a very useful tool for aerodynamic calculation in the full cycle design activity. This software utilizes the panel method enhanced on a boundary layer model for determination of the fundamental aerodynamic characteristic of an arbitrary aircraft. Presented paper shows a very efficient way how to compute the aerodynamics necessary for design of a new MALE class UAV.
This paper presents analyzed questions of the safety of the information transferred by the radio connection link of the Polish UAV project “Aircraft for monitoring” SAMONIT. This safety is especially important for the design and use of unmanned aerial vehicles (UAV). This paper also presents the structure of the SAMONIT communication system, security threats to the radio connection system, and possible measures to ensure secure information. Santrauka Straipsnyje nagrinejami Lenkijos bepiločiu orlaiviu projekto SAMONIT (monitoringo lektuvas) radijo ryšiu perduodamos informacijos saugumo klausimai. Ypač svarbi yra radijo ryšiu perduodamos informacijos apsauga kuriant bepiločius orlaivius (BO) ir kitas nuotolinio valdymo transporto priemones. Straipsnyje pateikiama SAMONIT ryšiu sistemos struktūra, galimos gresmes informacijos perdavimui, saugumui bei integralumui; taip pat radijo ryšio sistemos apsaugos būdai bei priemones.
Purpose Bird strike and hail impact resistances are considered in relation to the fulfilment of airworthiness/crashworthiness regulations as specified by appropriate aviation authorities. Before aircraft are allowed to go into service, these regulations must be fulfilled. This includes the adaption of the wing leading edge (LE) structure to smart diagnostics and an easy repair. This paper aims to focus on the wing LE, although all forward-facing aircraft components are exposed to the impact of foreign object during the flight. The best practices based on credible simulations which may be appropriate means of establishing compliance with European Aviation safety Agency and Federal Aviation Administration regulations regarding bird strikes, together with the problem of collisions with hailstones, are overviewed in aspect of accuracy and computing cost. Design/methodology/approach The best means of evaluating worldwide certification standards so as to be more efficient for all stakeholders by reducing risk and costs (time and money consuming) of certification process are recommended. The very expensive physical tests may be replaced by adequate and credible computer simulations. The adequate credible simulation must be verified and validated. The statistical approaches for modelling the uncertainty are presented in aspect of computing cost. Findings The simulation models have simplifications and assumptions that generate an uncertainty. The uncertainty must be identified in benchmarking tests. Instead of using “in house” physical tests, there are scientific papers available in open literature thanks to the new trend in worldwide publication of the research results. These large databases can be efficiently transform into useful benchmark thanks to data mining and knowledge discovery methods and big data analyses. The physical test data are obtained from tests on the ground-based demonstrator by using high-speed cameras and a structural health monitoring system, and therefore, they should be applied at an early stage of the design process. Originality/value The sources of uncertainty in simulation models are expressed, and the way to their assessment is presented based on statistical approaches. A brief review of the current research shows that it widely uses efficient numerical analysis and computer simulations and is based on finite element methods, mesh structure as well as mesh free particle models. These methods and models are useful to analyse airworthiness requirements for damage tolerance regarding bird-strike and hail impact and haves been subjected to critical review in this paper. Many original papers were considered in this analysis, and some of them have been critically reviewed and commented upon.
PurposeTo provide an overview of design activity undertaken within the CAPECON Project supported by European Commission and devoted to development of HALE UAV being proposed for long endurance flights.Design/methodology/approachSelected research methods devoted mainly to the improvement of dynamic stability of unmanned aerial vehicles have been described and their application into design optimisation are shown. The main goal of this research was to improve an economic effectiveness, safety and a modular arrangement of on‐board systems, especially with respect to sensors being easy replaceable for different missions.FindingsThe research and design process included an aerodynamic optimisation of swept wing, stability analysis, weight balance, some on‐board redundant systems, reliability and maintability analysis, safety improvement, cost and performance optimisation. A number of design iterations were performed to achieve the required aircraft performances and characteristics. This iteration number was relatively moderate (four cycles only) due to employing a modern software and the essential role of theoretical analysis performed parallel to the design and redesign process.Research limitations/implicationsAnalysis and design methodology is limited to surveillance, high altitude long endurance platforms, where the design objectives are high reliability, safety and low cost of production and operation.Practical implicationsA very useful source of design information and patterns to follow, especially for engineering students and engineers dealing with unmanned aviation.Originality/valueThis paper offers practical help for designers being involved with an unmanned platform to be well optimised for high altitude long endurance mission, giving a lot of practical information about many aspects of longitudinal and lateral stability of Blended Wing Body configuration, on‐board sensors and systems integrated with loading structure.
Purpose The purpose of this study is to investigate the influence of the technical and operational specifications of the Small Aircraft Transport System (SAT/SATS) to the achieved safety level. Design/methodology/approach Safety estimation was made with the use of mathematical model of safety of light aircraft in commercial operations developed on the basis of Federal Aviation Administration (FAA) data. The analysis was conducted for two different SATS business models based on Direct AiR Transport (DART) concept. It allowed for the investigation of the impact of technical specifications of the aircraft included into the SATS fleet as well as the selected elements of the applied business model on SATS safety level. Findings It was found that the proposed changes to DART system resulted in a significant improvement of safety. Mean Time Between Incidents and Accident (MTBIA) increased by 200 per cent. Additionally, the introduced alterations impacted the weights of particular domains and pilot’s error became less critical than the technical reliability. Practical implications It was shown that the application of new requirements influences both the safety level and the cost of operation, which was demonstrated within the ESPOSA and DART projects. Additionally, it was indicated that further effort to improve the light aircraft safety is absolutely necessary. Originality/value Originality consists in combining in one mathematical model both the aircraft configuration and the rules for business operation. Optimization of selected parameters of the system leads to a significant reduction in the accident number and to keeping the cost increment at a reasonable level. It was also found that the resulted improvement sometimes cannot be sufficient to consider a small aircraft operation fully safe, mainly owing to the numerous restrictions because of its small weight and loading capacity.
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