The effect of folding wingtips on the worst-case gust loads of a simplified aircraft model

Abstract

In recent years, the development of lighter and more efficient transport aircraft has led to an increased focus on gust load alleviation. A recent strategy is based on the use of folding wingtip devices that increase the aspect ratio and therefore improve the aircraft performance. Moreover, numerical studies have suggested such a folding wingtip solution may incorporate spring devices in order to provide additional gust load alleviation ability in flight. It has been shown that wingtip mass, stiffness connection and hinge orientation are key parameters to avoid flutter and achieve load alleviation during gusts. The objective of this work is to show the effects of aeroelastic hinged wingtip on the problem of worst-case gust prediction and the parameterization and optimization of such a model for this particular problem, that is, worst-case gust load prediction. In this article, a simplified aeroelastic model of full symmetric aircraft with rigid movable wingtips is developed. The effects of hinge position, orientation and spring stiffness are considered in order to evaluate the performance of this technique for gust load alleviation. In addition, the longitudinal flight dynamics of a rigid aircraft with an elastic wing and folding wingtips is studied. Multi-objective optimizations are performed using a genetic algorithm to exploit the optimal combinations of the wingtip parameters that minimize the gust response for the whole flight envelope while keeping flutter speed within the safety margin. Two strategies to increase flutter speed based on the modification of the wingtip parameters are presented.

Development of a digital twin operational platform using Python Flask

“…Flask is a Python-based module that produces a web page-like application that utilizes HTML, CSS, and JavaScript (see, e.g., Grinberg, 2018; Nixon, 2014). An additional benefit for using Flask is that this work was undertaken as part of a multi-institutional research project (see the Acknowledgment section for details; published work from the project includes Wagg et al, 2020; Balatti et al, 2021; Beregi et al, 2021; Chakraborty and Adhikari, 2021; Chatterjee et al, 2021; Jamia et al, 2021; Gray et al, 2022), and this format was a natural choice for multiuser access with users based at multiple different geographical locations.…”

On the Effect of Geometric Nonlinearity on the Dynamics of Flared Folding Wingtips

“…Whilst the wingtips of the 777X can only be operated on the ground, the inclusion of such a mechanism raises the question as to whether folding wingtips can be utilised in-flight for aerodynamic or structural benefits. One such solution is the Flared Folding Wingtip (FFWT) [8][9][10][11][12][13][14][15][16][17][18]. As illustrated in Fig.…”

Experimental Analysis of the Dynamics of Flared Folding Wingtips via a Novel Tethered Flight Test

“…One such device, the Flared Folding Wingtip (FFWT) concept, has received significant research effort [17][18][19][20][24][25][26][27][28][29][30]. As illustrated in Fig.…”

“…The primary use of an FFWT is as a passive gust load alleviation device, with both experimental [18,24] and numerical simulations [17,19,25] highlighting that significant reductions in the peak wing root bending stress can be achieved during gust and manoeuvre loading, when compared to a fixed wingtip configuration. Further work has aimed to quantify the effect of FFWTs on the handling qualities [20] and roll performance [31] of an aircraft and previous flight tests have been conducted using the AlbatrossOne UAV [32], which is shown in Fig 2 and is the test structure considered within this paper.…”