Aeroelastic Assessments and Functional Hazard Analysis of a Regional Aircraft Equipped with Morphing Winglets

Abstract

The application of morphing wing devices can bring several benefits in terms of aircraft performance, as the current literature shows. Within the scope of Clean Sky 2 AirGreen 2 European project, the authors provided a safety-driven design of an adaptive winglet, through the examination of potential hazards resulting from operational faults, such as actuation chain jamming or links structural fails. The main goal of this study was to verify whether the morphing winglet systems could comply with the standard civil flight safety regulations and airworthiness requirements (EASA CS25). Systems functions were firstly performed from a quality point of view at both aircraft and subsystem levels to detect potential design, crew and maintenance faults, as well as risks due to the external environment. The severity of the hazard effects was thus identified and then sorted in specific classes, representative of the maximum acceptable probability of occurrence for a single event, in association with safety design objectives. Fault trees were finally developed to assess the compliance of the system structures to the quantitative safety requirements deriving from the Fault and Hazard Analyses (FHAs). The same failure scenarios studied through FHAs have been simulated in flutter analyses performed to verify the aeroelastic effects due to the loss of the actuators or structural links at aircraft level. Obtained results were used to suggest a design solution to be implemented in the next loop of design of the morphing winglet.

Multidisciplinary Optimization for Weight Saving in a Variable Tapered Span-Morphing Wing Using Composite Materials—Application to the UAS-S4

“…These earlier works investigated the multidisciplinary numerical optimization of MVSTW, which integrated automated numerical analyses of aerodynamics, Finite Element Method, and structure optimizations [31]. Aerodynamic analyses have established that increasing the wing area via the span-morphing technique improved its aerodynamic performance, reduced fuel consumption, and increased flight envelope range [32][33][34]. Another advantage was the ability to dominate roll control using the asymmetric wingspan mechanism rather than conventional control surfaces [35].…”

Aerodynamic Design Optimization of a Morphing Leading Edge and Trailing Edge Airfoil–Application on the UAS-S45

“…To meet environmental guidelines, including those of the International Civil Aviation Organization's (ICAO's) Committee on Aviation Environmental Protection (CAEP), innovative technologies such as "morphing" are fascinating as they provide advantages over conventional wing configurations [10]. Additionally, "morphing" is more practically applied in Unmanned Aerial Vehicles (UAVs) because of their reduced scale and lower complexity in terms of wing design structure and energy consumption expressed in terms of actuation power [6,11,12], in addition to the advantages that morphing designs are lighter and less noisy than their conventional designs. Some morphing opportunities with potential benefits for increasing aerodynamic performance of the UAS-S45 are shown in Figure 1.…”

Investigation of Reynolds Number Effects on Aerodynamic Characteristics of a Transport Aircraft

“…In this paper, an in-house developed CFD tool that has been validate experimental data is used to correct the wing deformation effect [31] and a tailed flow structure over the transport aircraft model. Closely combining w wind tunnel test results, the Reynolds number scaling effects on aerodyna istics of transport aircraft and their mechanism are analyzed in this pape model configuration and the corresponding experimental and numerical se duced in Section 2.…”