Commuter aircraft aerodynamic design: wind-tunnel tests and CFD analysis

The paper presents wind-tunnel tests and CFD numerical aerodynamic analysis of Tecnam P2012 Traveller aircraft. An extensive wind tunnel tests campaign of several different modular aircraft configurations analyzed has been performed on a scaled model in order to experimentally estimate both longitudinal and lateral-directional stability, control derivatives, and to improve the aircraft aerodynamic performances. Simultaneously numerical investigations through a CFD software has been performed, both at wind-tunnel tests Reynolds number (Re=0.6millions) and at free flight Reynolds number of the full scale aircraft (Re=4 or 9 millions). Finally results are compared showing a good agreement in the lift and pitching moment coefficient both with and without control surfaces or flap deflections, and an underestimation of drag coefficient in the CFD numerical analysis. Horizontal tail positions are also tested in wind-tunnel and compared to CFD analysis highlighting how an accurate design leads to improvement both in stability and control. Results will be very useful in the final design of the aircraft and to perform dynamic simulations

Advanced turboprop multidisciplinary design and optimization within agile project

The present paper deals with the design, analysis and optimization of a 90 passengers turboprop aircraft with a design range of 1200 nautical miles and a cruise Mach number equal to 0.56. The prescribed aircraft is one of the use cases of the AGILE European project, aiming to provide a 3rd generation of multidisciplinary design and optimization chain, following the collaborative and remote aircraft design paradigm, through an heterogenous team of experts. The multidisciplinary aircraft design analysis is set-up involving tools provided by AGILE partners distributed worldwide and run locally from partners side. A complete design of experiment, focused on wing planform variables, is performed to build response surfaces suitable for optimization purposes. The goal of the optimization is the direct operating cost, subject to wing design variables and top-level aircraft requirements

Structural validation of a realistic wing structure: the RIBES test article

Several experimental test cases are available in literature to study and validate fluid structure interaction methods. They, however, focus the attention mainly on replicating typical cruising aerodynamic conditions forcing the adoption of fully steel made models able to operate with the high loads generated in high speed facilities. This translates in a complete loss of similitude with typical realistic aeronautical wing structures configurations. To reverse this trend, and to better study the aerolastic mechanism from a structural point of view, an aeroelastic measurement campaign was carried within the EU RIBES project. A half wing model for wind tunnel tests was designed and manufactured replicating a typical metallic wing box structure, producing a database of loads, pressure, stress and deformation measurements. In this paper the design, manufacturing and validation activities performed within the RIBES project are described, with a focus on the structural behavior of the test article. All experimental data and numerical models are made freely available to the scientific community

Focusing on autism spectrum disorder in xia–gibbs syndrome: Description of a female with high functioning autism and literature review

Background: Xia–Gibbs syndrome (XGS) is a rare disorder caused by de novo mutations in the AT-Hook DNA binding motif Containing 1 (AHDC1) gene, which is characterised by a wide spectrum of clinical manifestations, including global developmental delay, intellectual disability, structural abnormalities of the brain, global hypotonia, feeding problems, sleep difficulties and apnoea, facial dysmorphisms, and short stature. Methods: Here, we report on a girl patient who shows a peculiar cognitive and behavioural profile including high-functioning autism spectrum disorder (ASD) without intellectual disability and provide information on her developmental trajectory with the aim of expanding knowledge of the XGS clinical spectrum. On the basis of the current clinical case and the literature review, we also attempt to deepen understanding of behavioural and psychiatric manifestations associated with XGS. Results: In addition to the patient we described, a considerable rate of individuals with XGS display autistic symptoms or have been diagnosed with an autistic spectrum disorder. Moreover, the analysis of the few psychopathological profiles of patients with XGS described in the literature shows a frequent presence of aggressive and self-injurious behaviours that could be either an expression of autistic functioning or an additional symptom of the ASD evolution. A careful investigation of the abovementioned symptoms is therefore required, since they could represent a “red flag” for ASD

Methodological enhancements in MDO process investigated in the AGILE European project

This paper presents methodological investigations performed in research activities in the field of MDO in overall aircraft design in the ongoing EU funded research project AGILE. AGILE is developing the next generation of aircraft Multidisciplinary Design and Optimization processes, which target significant reductions in aircraft development costs and time to market, leading to cheaper and greener aircraft solutions. The paper introduces the AGILE project structure and describes the achievements of the 1st year (Design Campaign 1) leading to a reference distributed MDO system. A focus is then made on the different novel optimization techniques studied during the 2nd year, all willing to ease the optimization of complex work flows, characterized by high degree of discipline interdependencies, high number of design variables in the context of multi-level and multi-partner collaborative engineering projects. Then the implementation of these methods in the enhanced MDO framework is discussed

Design and aerodynamic analysis of a regional turboprop innovative configuration

This paper deals with the fundamental results of the first loop of design and aerodynamic analysis of a new regional turboprop concept. The aircraft has a low wing and two innovative architecture of turboprop engine installed at the horizontal tail tips. It can seat up to 130 passengers with a design range of about 3000km. It is designed to fly at Mach number of about 0.62 at a cruise altitude of 9000m with an efficiency about 18. The required maximum lift coefficients in clean, take-off and landing conditions are 1.6, 2.4 and 3.0 respectively. Wing sections have been specifically designed to comply with the very challenging requirements in terms of minimum drag (natural laminar flow), maximum clean lift coefficients and compressibility effects. The high lift devices have been designed too. A single fowler flap layout has been considered. To augment the aircraft maximum lift capabilities in landing condition, preserving the wing laminar flow, the effects of a simple droop nose have been investigated. To improve climb performance a specific winglet design has been assessed, results show that a reduction of about 10% of the induced drag during both climb and cruise phase could be achieved. All the criticalities emerged during the first loop will feed a second design loop to well asses this innovative concept

Factors associated with SARS-CoV-2 infection risk among healthcare workers of an italian university hospital

We report the results of a study on the cumulative incidence of SARS-CoV-2 infections in about 6000 workers of the University Hospital of Modena, Northern Italy, in the period March 2020–January 2021, and the relations with some individual and occupational factors. Overall, in healthcare workers (HCW) the cumulative incidence of COVID-19 during the period was 13.8%. Results confirm the role of overweight and obesity as significant risk factors for SARS-CoV-2 infection. Chronic respiratory diseases, including asthma, also proved to be significantly associated with the infection rate. Considering occupational factors, the COVID-19 risk was about threefold (OR: 2.7; 95% CI 1.7–4.5) greater in nurses and nurse aides than in non-HCW, and about double (OR: 1.9; 95% CI 1.2–3.2) in physicians. Interestingly, an association was also observed between infection risk and nightshifts at work (OR: 1.8; 95% CI 1.4–2.3), significantly related to the total number of shifts in the whole eleven-month period. Even if the vaccination campaign has now greatly modified the scenario of SARS-CoV-2 infections among HCW, the results of this study can be useful for further development of health and policy strategies to mitigate the occupational risk related to the new variants of coronavirus, and therefore the evolution of the pandemic

Multidisciplinary Design and Optimization of Regional Jet Retrofitting Activity

A retrofit analysis on a 90 passengers regional jet aircraft is performed through a multidisciplinary collaborative aircraft design and optimization highlighting the impact on costs and performance. Two different activities are accounted for selecting the best aircraft retrofit solution: a re-engining operation that allows to substitute a conventional power-plant platform with advanced geared turbofan and an on-board-systems architecture modernization, considering different levels of electrification. Besides the variables that are directly dependent from these activities, also scenario variables are considered during the optimization such as the fuel price, the fleet size and the years of utilization of the upgraded systems. The optimization is led by impacts of the retrofitting process on emissions, capital costs and saving costs, computed at industrial level. Overall aircraft design competences (aerodynamics, masses, performance, noise, and emissions) have been computed increasing the level of fidelity and reliability. The whole process is implemented in the framework of the AGILE 4.0 research project in a collaborative remote multidisciplinary approach. Results show that the engine retrofitting can be a profitable solution for both manufacturers and airliners. Conversely, the on-board-system electrification seems to be not convenient in a retrofitting process due to the high capital costs. Depending on the operative scenario, involved stakeholders can properly orient their decision on a retrofitting strategy

Innovative tools for aircraft preliminary design – development, applications and education

The Design of Aircraft and Flight Technologies Research Group (DAF) at University of Naples is involved in research activities addressing the development and application of new and innovative tools and frameworks for aircraft preliminary design. To build such new tools for aircraft design we believe that the following activities should be carried out: (a) derive new semi-empirical formulations (even through the construction of surrogate methods) which can be more accurate in the prediction of aircraft characteristics (especially for non-conventional configurations); (b) integrate medium to high fidelity tools into the analyses; (c) design with a multidisciplinary approach (i.e. including systems and direct operating costs); (d) include innovative propulsive systems; (e) deal with innovative configurations; (f) include new and efficient optimization algorithms; (g) use advanced software engineering to enhance tool capabilities, speed and usability (for example user-friendly graphic interface or inter-operability with other software). Recent research activities of the DAF group have been focused on the development and application of a new framework. Examples and applications in relevant European research projects can be presented. The development of these tools play also a relevant role in educational activities at the University of Naples as far aircraft design is concerned