Multi-fidelity weight analyses for high aspect ratio strut-braced wings preliminary design

Abstract

In the wake of ”flygskam” movement that emerged in Sweden a couple of years ago many voices recently raised denounce the environmental footprint of aviation. Even if the real impact of the sector could appear rather limited the critics reveal the necessity to propose cleaner aircraft to both meet public expectations and environmental goals. Because the classical wing-tube configuration seems to have reached its limits, disruptive designs must be considered. Among the perspectives to reduce emissions, high-aspect ratio wings represent a promising path to be explored within the European CleanSky2 project U-HARWARD. Indeed, substantial diminution of induced drag are expected from those new configurations resulting in fewer fuel consumption. To achieve high-aspect ratio without compromising the structural weight strut can be introduced. They allow for an alleviation of the bending moment at the wing root and therefore lighter structures. However, the consideration of those new wing configuration at early design stages is not straightforward and new methods have to be introduced. In this paper, we present three different fidelity approaches to tackle with (ultra) high-aspect ratio strut-braced wings sizing and weight estimation in preliminary design context. Already existing analytical formulations for the wings are extended, intermediate fidelity aero-structural coupling has been developed and high-fidelity structural representation are considered. Depending on the maturity of the concept these methods could be used to explore the design space, to refine the optimum or to analyse the final concept. Validation with respect to reference configurations is provided. Then the methods are applied to the analysis of strut-braced wings.

Wind tunnel flutter tests of a strut-braced high aspect ratio wing

“…Reference aircraft is an Onera concept [1,2]. Typical mission and fuselage use an Airbus A321 as a baseline.…”

Study on the Actuation Aspects for a Morphing Aileron Using an Energy–Based Design Approach

“…Global efficiency can be improved by maximizing the aerodynamic efficiency or minimizing the structural weight. A high-aspect-ratio wing (HARW) or ultra-highaspect-ratio wing (UHARW) can increase aerodynamic efficiency [9,10], but need to select non-conventional structural configurations, such as a strut-truss-braced wing [11] that also allows to reduce the structural weight. Indeed, the strut-braced-wing (SBW) configuration allows to reduce the bending moment to be carried out by the inner-wing structure and then limits the weight penalty, while combining the aerodynamic benefits of HARW [12].…”