Aircraft Engineering and Aerospace Technology

Goetzendorf-Grabowski, Tomasz

2018 Aircraft Engineering and Aerospace Technology

doi: 10.1108/AEAT-02-2018-0086

Galinski, Cezary; Krysztofiak, Grzegorz; Miller, Marek; Ruchala, Pawel; Kalski, Marek; Lis, Mateusz; Dziubinski, Adam; Bogdanski, Krzysztof; Stefanek, Lukasz; Hajduk, Jaroslaw

2018 Aircraft Engineering and Aerospace Technology: An International Journal

doi: 10.1108/AEAT-11-2016-0195

PurposeThe purpose of this paper is to present the methodology and approach adapted to conduct a wind tunnel experiment on the inverted joined-wing airplane flying model together with the results obtained.Design/methodology/approachGeneral assumptions underlying the dual-use model design are presented in this paper. The model was supposed to be used for both wind tunnel tests and flight tests that significantly drive its size and internal structure. Wind tunnel tests results compared with the outcome of computational fluid dynamics (CFD) were used to assess airplane flying qualities before the maiden flight was performed.FindingsExtensive data about the aerodynamic characteristics of the airplane were collected. Clean configurations in symmetric and asymmetric cases and also configurations with various control surface deflections were tested.Practical implicationsThe data obtained experimentally made it possible to predict the performance and stability properties of the unconventional airplane and to draw conclusions on improvements in further designs of this configuration.Originality/valueThe airplane described in this paper differs from frequently analyzed joined-wing configurations, as it boasts a front lifting surface attached at the top of the fuselage, whereas the aft one is attached at the bottom. The testing technique involving the application of a dual-use model is also innovative.

Goraj, Zdobyslaw Jan; Kustron, Kamila

2018 Aircraft Engineering and Aerospace Technology: An International Journal

doi: 10.1108/AEAT-02-2017-0053

PurposeBird 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/approachThe 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.FindingsThe 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/valueThe 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.

Jungo, Aidan; Zhang, Mengmeng; Vos, Jan B.; Rizzi, Arthur

2018 Aircraft Engineering and Aerospace Technology: An International Journal

doi: 10.1108/AEAT-11-2016-0204

PurposeThe purpose of this paper is to present the status of the on-going development of the new computerized environment for aircraft synthesis and integrated optimization methods (CEASIOM) and to compare results of different aerodynamic tools. The concurrent design of aircraft is an extremely interdisciplinary activity incorporating simultaneous consideration of complex, tightly coupled systems, functions and requirements. The design task is to achieve an optimal integration of all components into an efficient, robust and reliable aircraft with high performance that can be manufactured with low technical and financial risks, and has an affordable life-cycle cost.Design/methodology/approachCEASIOM (www.ceasiom.com) is a framework that integrates discipline-specific tools like computer-aided design, mesh generation, computational fluid dynamics (CFD), stability and control analysis and structural analysis, all for the purpose of aircraft conceptual design.FindingsA new CEASIOM version is under development within EU Project AGILE (www.agile-project.eu), by adopting the CPACS XML data-format for representation of all design data pertaining to the aircraft under development.Research limitations/implicationsResults obtained from different methods have been compared and analyzed. Some differences have been observed; however, they are mainly due to the different physical modelizations that are used by each of these methods.Originality/valueThis paper summarizes the current status of the development of the new CEASIOM software, in particular for the following modules: CPACS file visualizer and editor CPACSupdater (Matlab) Automatic unstructured (Euler) & hybrid (RANS) mesh generation by sumo Multi-fidelity CFD solvers: Digital Datcom (Empirical), Tornado (VLM), Edge-Euler & SU2-Euler, Edge-RANS & SU2-RANS Data fusion tool: aerodynamic coefficients fusion from variable fidelity CFD tools above to compile complete aero-table for flight analysis and simulation.

Immer, Marc; Juretzko, Philipp Georg

2018 Aircraft Engineering and Aerospace Technology: An International Journal

doi: 10.1108/AEAT-11-2016-0205

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.

Fusaro, Roberta; Viola, Nicole

2018 Aircraft Engineering and Aerospace Technology: An International Journal

doi: 10.1108/AEAT-11-2016-0214

PurposeThis paper aims to propose a methodology for a safety and reliability assessment for the conceptual and preliminary design of very complex and disrupting innovative systems like trans-atmospheric vehicles. The proposed methodology differs from existing ones because it does not rely on statistical data at aircraft-level but exploits the statistical population at components-level only. For the sake of clarity, the paper provides some preliminary results of the application of the methodology at system level. The example deals with the safety and reliability assessment of a very complex propulsion system aimed at guaranteeing vertical take-off and landing capabilities of a suborbital vehicle.Design/methodology/approachThe proposed methodology is strongly based on a systems engineering approach. It exploits safety and reliability assessment analyses which have already been developed in both aeronautical and space engineering domains, but it combines them in an innovative way to overcome the lack of statistics at aircraft level. The methodology consists of two different steps: a qualitative top-down process, allowing a functional and physical decomposition of the transportation system and a following quantitative bottom-up approach, which provides the estimation of system-level reliability and safety characteristics starting from the statistical estimation of the components’ characteristics.FindingsThe paper presents a new methodology for the preliminary reliability and safety assessment of innovative transportation systems, such as hypersonic transportation systems. The envisaged methodology will overcome the poorness of statistical data that is usually affecting the conceptual design of breakthrough systems.Research limitations/implicationsThe paper shows the application of the articulated methodology to a limited case study. A complete example of application of the methodology to estimate safety and reliability characteristics at vehicle level will be provided in feature works.Practical implicationsThe methodology has been proposed to be exploited in international research activities in the field of hypersonic transportation systems. Furthermore, a massive application of this approach would allow to create a database for the generation and the update of semi-empirical models focused on high-level estimations of reliability, availability, maintainability and safety (RAMS) characteristics. Moreover, the proposed safety assessment has been conceived to be fully integrated within a typical conceptual design process.Originality/valueThe existing literature about safety and reliability assessment at the early design stages proposes pure statistical approaches which are usually not applicable to highly innovative products, where the statistical population is not existing, for example, in the case of trans-atmospheric vehicles. This paper describes how to overcome this problem, through the exploitation of statistical data at components-level only through the combination of these data to estimate RAMS characteristics at aircraft-level thanks to functional analysis, concept of operations and typical safety assessment tools, like functional hazard analysis, failure mode and effect analysis, reliability block diagram and fault tree analysis.

Deák, Péter

2018 Aircraft Engineering and Aerospace Technology: An International Journal

doi: 10.1108/AEAT-11-2016-0212

PurposeThe purpose of this paper is to make an analytical comparison of two vertical tail models from a structural point of view.Design/methodology/approachThe original vertical tail design of PZL-106BT aircraft was used for Computer aided design (CAD) modeling and for creating the finite element model.FindingsThe nodal displacements, Von-Mises stresses and Buckling factors for two vertical tail models have been found using the finite element method. The idea of a possible Multidisciplinary concept assessment and design (MDCAD) concept was presented.Practical implicationsThe used software analogy introduces an idea of having an automated calculation procedure within the framework of MDCAD.Originality/valueThe aircraft used for calculation had undergone a modification in its vertical tail length, as there was an urgent need to calculate for the plane’s manufacturer, PZL Warszawa – Okecie.

Dziugiel, Bartosz; Goraj, Zdobyslaw Jan

2018 Aircraft Engineering and Aerospace Technology: An International Journal

doi: 10.1108/AEAT-01-2017-0027

PurposeThe 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/approachSafety 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.FindingsIt 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 implicationsIt 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/valueOriginality 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.

Rodzewicz, Miroslaw; Glowacki, Dominik; Szczepanik, Tomasz; Hajduk, Jaroslaw

2018 Aircraft Engineering and Aerospace Technology: An International Journal

doi: 10.1108/AEAT-11-2016-0222

PurposeThe purpose of this paper is to describe the results of investigations of parachute rescue systems (PRS) for light gyrocopters.Design/methodology/approachAlthough the investigations were conducted in both stages simultaneously, i.e. experimental mechanics approach and numerical simulations, the paper is focussed mainly on the experimental part of the work. To ensure the safety of experimental works (i.e. for both experimenters and bystanders), the authors applied unmanned, remotely controlled scale models of autogyro for the PRS testing in the air.FindingsThe critical problem for successful use of the PRS is that the rotation of the rotor blades must be stopped when the main parachute opens, otherwise the influence of the rotor on the improper opening process of the parachute may cause the whole PRS to become useless.Research limitations/implicationsThe existing regulations for the use of unmanned aircraft impose the limitation upon the organisation of in-flight tests of PRS, i.e. the maximum take-off mass of the tested gyrocopter models is limited, and a full-scale test needs the approval of European Aviation Safety Agency (EASA).Practical implicationsThe research contributes to increasing the safety level for gyrocopter users. The authors elaborated the original PRS, which currently is in the process of patenting.Originality/valueOriginality of the work consists of both an innovative PRS, which has never been tested before, and the results of experimental investigations, which cover both ground tests carried on static or moving stands and in-flight testing.

Cejpek, Jakub

2018 Aircraft Engineering and Aerospace Technology: An International Journal

doi: 10.1108/AEAT-11-2016-0216

PurposeThe purpose of this paper is to introduce a software tool under development by the author. Based on industry demands, a software tool is developed to fill the gap between commercial software and limited closed-form analysis in this specific area.Design/methodology/approachPython programming language offers a great potential to develop relatively simple software that includes graphical user interface and can be turned into an executable file – therefore easily spread. Also, thanks to large community, Python offers extended scientific libraries for solving number of engineering problems. Results are compared to the commercially available software (in this case, MSC NASTRAN). Further evaluation is done to compare results to the laboratory tests.FindingsFirst results were obtained from the comparison between KuFEM and NASTRAN. These results are sufficient reassurance for next stages of development. Next results are the comparison of KuFEM results to the laboratory test. As only one type of product has been tested, no final conclusion can be made. However, within these limits, the results are very promising and optimistic.Research limitations/implicationsFuture development will include further evaluation on different products, even more composite-oriented calculations, enhanced graphical environment.Practical implicationsKuFEM, within its limits, is an alternative to other commercial programs. It is meant to compromise between limited closed-form designs and detailed designs in expensive software.Originality/valueKuFEM is a unique software tool. It allows user to work with finite element method in a simple preprogrammed way. It enhances the standard BEAM elements to go deeper in the analysis. Currant evaluation promises potential good results.