Roeland De Breuker

• PhD in Aeroelasticity
• Professor (Associate) at Delft University of Technology

The design and optimisation of aircraft wings are critical tasks in aerospace engineering, requiring a balance between structural integrity, aerostructural performance, and manufacturability. This multifaceted challenge involves the interplay of various disciplines, each with distinct parameters and constraints. Traditional design approaches often...

This paper proposes an incremental nonlinear control method for an aeroelastic system’s gust load alleviation and active flutter suppression. These two control objectives can be achieved without modifying the control architecture or the control parameters. The proposed method has guaranteed stability in the Lyapunov sense and also has robustness ag...

The ram air inlets flaps are used in some aircraft to modulate the amount of ram air cooling the Environmental Control System. The current flap design features two metallic plates connected with a hinge. The present work studies an alternative design that replaces the metallic plates with a single composite laminate with morphing capabilities. An o...

This study presents an aeroelastic wind-tunnel experiment to identify the influence of the wing stiffness and hinge release threshold on the gust load alleviation performance of a folding wingtip design. Five models with different stiffness and tailoring properties are tested, and the wing root bending moment at different conditions is compared to...

Wing structures subjected to large deflections are prone to nonlinear load-deflection behavior. Geometric nonlinearities can arise due to the accompanying large rotations and in-plane deflections that manifest in the form of stiffening effects in the nonlinear static response. To account for these nonlinearities, reduced-order modeling techniques i...

In this paper, an innovative design methodology is proposed to simultaneously optimize the size, layout, and number of stiffeners of a stiffened panel using a gradient-based optimizer. In the proposed method, CAD-based parameterization is used to parameterize the layout of the stiffeners. The location and orientation of each stiffener are controlle...

Morphing structures have acquired much attention in the aerospace community because they enable an aircraft to actively adapt its shape during flight, leading to fewer emissions and fuel consumption. Researchers have designed, manufactured, and tested a morphing wing named SmartX-Alpha, which can actively alleviate loads while achieving the optimal...

This article describes the challenges of integrating smart sensing, actuation, and control concepts into an over-sensed and over-actuated technology integrator. This technology integrator has more control inputs than the expected responses or outputs (over-actuated), and its every state is measured using more than one sensor system (over-sensed). T...

This work presents a new aeroelastic optimisation framework for the preliminary design of variable stiffness composite wing structures. The framework is constructed by sequentially and iteratively solving two sub-problems: aeroelastic tailoring and lay-up retrieval, using gradient-based algorithms with full-analytical sensitivities provided. During...

This article presents the application of aeroelastic tailoring in the design of wings for a flying demonstrator, as well as the validation of the design methodology with flight test results. The investigations were performed in the FLEXOP project (Flutter Free Flight Envelope Expansion for Economical Performance Improvement), funded under the Horiz...

An innovative design methodology is proposed for the simultaneous layout and sizing optimization of stiffened panels. A computer-aided design (CAD) modelling tool is used to generate the panel geometry and parameterize the stiffeners layout. The same geometric parameterization is used in the gradient-based optimization. Therefore no additional cons...

Structural mechanics is commonly modeled by (systems of) partial differential equations (PDEs). Except for very simple cases where analytical solutions exist, the use of numerical methods is required to find approximate solutions. However, for many problems of practical interest, the computational cost of classical numerical solvers running on clas...

This paper exposes that although some sensor-based nonlinear fault-tolerant control frameworks including incremental nonlinear dynamic inversion control can passively resist a wide range of actuator faults and structural damage without requiring an accurate model of the dynamic system, their stability heavily relies on a sufficient condition, which...

An aeroelastic wind tunnel experiment to identify the influence of the wing stiffness and hinge release threshold on the gust load alleviation performance of a folding wingtip design is presented in this study. Five models with different stiffness and tailoring properties are tested and the wing root bending moment at different conditions is compar...

View Video Presentation: https://doi.org/10.2514/6.2022-1551.vid This study investigated the design and development of an autonomous aeroservoelastic wing concept with distributed flaps. This wing demonstrator was developed in the scope of the SmartX project, aiming to demonstrate in-flight performance optimization and multi-objective control with...

View Video Presentation: https://doi.org/10.2514/6.2022-0173.vid This paper presents an overview of the design and validation of a novel passive camber morphing system for rotorcraft. The passive system works for a variable speed rotor where a potential increase in pilot control authority and power reduction is possible. In the proposed concept, th...

View Video Presentation: https://doi.org/10.2514/6.2022-0779.vid On the 15t hof December 1965 the motion picture “Flight of the Phoenix” was released in the United States of America theatres. In the closing movie credits the following text is shown:It should be remembered. . . that Paul Mantz, a fine man and a brilliant flyer gave his life in the m...

View Video Presentation: https://doi.org/10.2514/6.2022-2418.vid The paper proposes a methodology for increased-fidelity aeroelastic testing in a wind tunnel environment to improve the correlation between the aeroelastic response measured in a wind tunnel experiment and the aeroelastic response observed on an aircraft in flight. The focus of the cu...

View Video Presentation: https://doi.org/10.2514/6.2022-2169.vid Netherlands Aerospace Centre (NLR) and Delft University of Technology (TUD) have obtained an unmanned aerial vehicle to serve as a test platform for future aeroservoelastic flight testing. The purpose of this testbed is to collect data about flexible aircraft flight dynamic responses...

Pdf available here: http://pure.tudelft.nl/ws/portalfiles/portal/104464061/Discrete_time_Design_and_Stability_Analysis_for_Nonlinear_Incremental_Fault_tolerant_Flight_Co.pdf

View Video Presentation: https://doi.org/10.2514/6.2022-1840.vid Morphing is a promising bio-inspired technology, with the potential to make aircraft more economical and sustainable through adaptation of the wing shape for best efficiency at any flight condition. This paper proposes an online black-box performance optimization strategy for a seamle...

The sensor-based Incremental Nonlinear Dynamic Inversion (INDI) control has shown promising robustness in the aerospace research field. This control framework only requires a partial knowledge of plant (control effectiveness) because of its usage of angular accelerations and actuator output measurements. However, there are still un-negligible uncer...

Inspired by nature, smart morphing technologies enable the aircraft of tomorrow to sense their environment and adapt the shape of their wings in flight to minimize fuel consumption and emissions. A primary challenge on the road to this feature is how to use the knowledge gathered from sensory data to establish an optimal shape adaptively and contin...

This paper presents an approach for optimizing practical commercial-scale aircraft wings using sandwich composites in a preliminary design stage. The approach uses lamination parameters as design variables in a continuous optimization step. Structural constraints for classic composite laminate design such as material failure and buckling, and for s...

This paper presents an experimental method to detect in-situ the location of transition on a multi-segmental trailing edge camber morphing wing during synchronous and asynchronous morphing. The wing consists of six independently morphing segments with two of the segments instrumented with eight embedded piezoelectric sensors distributed uniformly a...

This paper discusses the development and whirl tower testing of an active translation induced camber morphing system for rotorcraft. The system deploys the morphing flap based on the amplitude and type of the input signal. As a case study, a demonstrator is developed and tested primarily under the centrifugal force generated by a whirl tower setup....

This paper proposes a nonlinear control architecture for flexible aircraft simultaneous trajectory tracking and load alleviation. By exploiting the control redundancy, the gust and maneuver loads are alleviated without degrading the rigid-body command tracking performance. The proposed control architecture contains four cascaded loops: position con...

The aim of the paper is to experimentally validate a numerical design methodology for optimizing composite wings subject to gust and fatigue loading requirements and to assess the effect of fatigue on the aeroelastic performance of the wing. Traditionally, to account for fatigue in composite design, a knockdown factor on the maximum stress allowabl...

This paper deals with the simultaneous gust and maneuver load alleviation problem of a seamless active morphing wing. The incremental nonlinear dynamic inversion with quadratic programming control allocation and virtual shape functions (denoted as INDI-QP-V) is proposed to fulfill this goal. The designed control allocator provides an optimal soluti...

Application of the aeroelastic analysis and design framework developed at Delft University of Technology to a design of two aeroelastically tailored composite wings for a flying demonstrator is presented. The objective of the design process is to minimize structural mass of the wing while maintaining a target cruise shape. For this purpose, the jig...

In the structural design of aircraft wings, aeroelastic tailoring is used to control the aeroelastic deformation to improve the aerostructural performance by making use of directional stiffness. Recently, tow-steered composites, where the fibre angles continuously vary within each ply, have been proven to have the potential to further expand the ad...

Advancements in aircraft controller design, paired with increasingly flexible aircraft concepts, create the need for the development of novel (smart) adaptive sensing methods suitable for aeroelastic state estimation. A potentially universal and noninvasive approach is visual tracking. However, many tracking methods require manual selection of init...

This paper presents an analysis of the interaction and trade-off between active aeroelastic control and passive structural tailoring on a free-flying fully flexible aircraft model. Both technologies are included in the preliminary design of a typical transport aircraft configuration with a conventional control surface layout containing trailing edg...

In this paper, we present a data-driven method to model the unsteady non-linear response of aircraft control surfaces. This method relies on aerodynamic reduced-order models (ROM) derived from computational fluid dynamics with Reynolds averaged Navier-Stokes (CFD-RANS) analysis in the transonic domain. The ROM consists of a combination of look-up t...

The presentation covered work performed by TU Delft and DLR on a hybrid aeroelastic tailoring process, in the framework of the European 7FP Smart Fixed Wing Aircraft (SFWA) project. Aim of the work package 'Adaptive Wing' in SFWA was to create design processes and solutions for aircraft wings giving optimal response with respect to loads, comfort a...

This paper proposes a nonlinear control architecture for flexible aircraft simultaneous trajectory tracking and load alleviation. By exploiting the control redundancy, the gust and maneuver loads are alleviated without degrading the rigid-body command tracking performance. The proposed control architecture contains four cascaded control loops: posi...

Advancements in aircraft controllers and the tendency towards increasingly lighter and more flexible aircraft designs create the need for adaptive and intelligent control systems. While lighter aircraft structures have the potential to show better structural and aerodynamic efficiency, they are also more susceptible to dynamic loads. A key aspect t...

In this study, the design and development of an autonomous morphing wing concept were investigated. The morphing wing was developed in the scope of the Smart-X project, aiming to demonstrate in-flight performance optimisation. This study proposed a novel distributed morphing concept, with six Translation Induced Camber (TRIC) morphing trailing edge...

This paper proposes a nonlinear control architecture for flexible aircraft simultaneous trajectory tracking and load alleviation. By exploiting the control redundancy, the gust and maneuver loads are alleviated without degrading the rigid-body command tracking performance. The proposed control architecture contains four cascaded control loops: posi...

Video of the dynamic deflection of a spoiler on a flexible wing simulated with the high-fidelity FSI framework used to validate the models developed in the article: Lancelot, P. , & De Breuker, R. (2021). Unsteady Non-linear Control Surface Modelling for Aeroservoelastic Applications. Journal of Aeroelasticity and Structural Dynamics, 8(1), 23-44....

This paper deals with the simultaneous gust and maneuver load alleviation problem of a seamless active morphing wing. The incremental nonlinear dynamic inversion with quadratic programming control allocation and virtual shape functions (denoted as INDI-QP-V) is proposed to fulfill this goal. The designed control allocator provides an optimal soluti...

Rotor morphing has been investigated in the past for improvement of rotor performance, either for reduction of rotor power demand or for vibratory load alleviation. The present study investigates the application of camber morphing for improvement of rotor performance in hover and vertical flight conditions, with a particular focus on the combinatio...

In this study, the design and development of an autonomous morphing wing concept were investigated. This morphing wing was developed in the scope of, the Smart-X project, aiming to demonstrate in-flight performance optimisation. This study proposed a novel distributed morphing concept, with six Translation Induced Camber (TRIC) morphing trailing ed...

In aircraft design, proper tailoring of composite anisotropic characteristics allows to achieve weight saving while maintaining good aeroelastic performance. To further improve the design, dynamic loads and manufacturing constraints should be integrated in the design process. The objective of this paper is to evaluate how the introduction of contin...

Ground testing campaign conducted on the FLEXOP demonstrator aircraft is presentedin this paper. The conducted tests are grouped in structural, flight system and integrationtests. Along with the description of the test setup and test execution, the main findingsand conclusions are also given. The structural tests comprise the static, ground vibrati...

The idea of the EU funded FLEXOP project is to raise efficiency of a currently existing wing by derivative solution with higher aspect ratio at no excess structural weight. In order to enable such a resulting highly flexible wing the project goal is to develop methods for active suppression of flutter and passive load alleviation. The developed met...

The article proposes a method developed for model order reduction in a Finite Element (FE) framework that is capable of computing higher order stiffness tensors. In the method, a truncated third order asymptotic expansion is used for transformation of an FE model to a reduced system. The basis matrix in the formulation of the reduced-order model (R...

The presentation sums up the objectives, requirements and achivements within Work Package 1 of the Horizon 2020 Project FLEXOP. It is part of the dedicated FLEXOP-Project Session during the 9th EASN Conference, held September 2019 in Athens, Greece

Objective Flight Phase Adaptive Aero-Servo-Elastic Aircraft Design Methods (FliPASED) opens a complete new dimension for the integrated aircraft design. Coupling between aeroelasticity, gust response, flight control methods, instrumentation and certification aspects is not exploited in current aircraft design. A common set of models, coupled with j...

An analytical model to predict the fatigue life of a composite laminate is formulated. The model calculates stresses in each ply using classical lamination theory, degrades the residual strength using the linear wear-out law and predicts failure based on Tsai Wu failure theory. The cycles to failure are predicted using the updated cycle-by-cycle pr...

The introduction of Urban Air Mobility (UAM) vehicles will initiate many new and unique challenges to the current operational airspace environment. Many of these challenges are researched today, and solutions are investigated. The main goal of this ongoing research is to develop a safe and sustainable UAM system looking at the design of vehicles an...

In this paper, a methodology is presented to size an aircraft wing-box accounting for steady and dynamic loads combined with active control. Several aerodynamic corrections are used and benchmarked to ensure a consistent level of fidelity during the load analysis. Reduced order models (ROM) of the aircraft movables, gust loads and maneuvers loads a...

Wings of modern aircraft have to be designed to give optimal response with respect to loads, comfort and performance. An essential part of the wing development is thus a design process which can take all these aspects into consideration. In the “Adaptive Wing” work package of the CleanSky “Smart Fixed Wing Aircraft” project, a multi-fidelity wing d...

This article presents an experimental evaluation of a morphing leading edge demonstrator by investigating its morphed shape, the level of induced strains in the airfoil skin, the actuation force, and the morphing mechanism’s capability to lock and transfer the applied loads. In addition, a finite element model of the demonstrator is assembled compr...

This paper designs an incremental nonlinear dynamic inversion control law for free-flying flexible aircraft, which can regulate rigid-body motions, alleviate gust loads, reduce the wing root bending moment, and suppress elastic modes. By fully exploring the sensor measurements, the model dependency of the proposed control law can be reduced while m...

This paper discusses the effects of the aerodynamic model on the design of a composite wing via aeroelastic tailoring. The classic framework for analysis and optimization of composite wings developed at Delft University of Technology adopts panel method aerodynamics to calculate static and dynamic loads. The current work expands the aerodynamic mod...

Including a gust analysis in an optimization framework is computationally expensive as the critical load cases are not known a priori and hence a large number of points within the flight envelope have to be analyzed. Model order reduction techniques can provide significant improvement in computational efficiency of an aeroelastic analysis. In this...

This paper presents an aeroelastic tailoring procedure used to design wing structures to meet strength, buckling, and flutter requirements simultaneously. The optimization process is divided into a continuous optimization step using lamination parameters, and a discrete optimization step, which produces detailed blended stacking sequences satisfyin...

The proposed approach in this paper aims to bring the accuracy of CFD to quick linear aeroelastic simulations for structural sizing. This is achieved by deriving reduced order models (ROM) of the aircraft movables, gust loads and manoeuvres loads from rigid CFD analysis and to use these as substitutes for the loads in the aeroelastic simulation. Th...

This paper presents the application of aeroelastic tailoring in the wing design of a flying demonstrator. The work is part of the Flutter Free Flight Envelope eXpansion (FLEXOP) project, funded under the Horizon 2020 framework. The project involves the design, manufacturing and flight-testing of a UAV toward two principle goals: i) to demonstrate t...

High aspect ratio strut braced aircraft can signif- icantly reduce the induced drag. The inherent anisotropic behaviour of the composite material along with their weight saving potential can im- prove the performance of the aircraft during the flight. Thus, a composite strut braced aircraft is one of the promising candidates to achieve the targets...

This video footage shows the flutter behavior of the scale model in the low-speed low-turbulence wind tunnel (LLT) of Delft University of Technology during the test campaign from 8 to 10 July 2013. The video starts from a camera perspective from inside one of the flutter constraints that restrict the possible motion of the wing tips and then contin...

This video is an assembly of high resolution photos showing the manufacturing of the wind tunnel model at Makani Power, CA, USA, and the subsequent setup of the experiment in the low-speed low-turbulence wind tunnel (LLT) of Delft University of Technology for the test campaign from 8 to 10 July 2013. The video is supplementary material for the jou...

This paper presents an extension of the simulation code ASWING to aeroelastic analysis of an airborne wind turbine. The device considered in this study consists of a tethered rigid wing with onboard-mounted wind turbines designed for wind energy harvesting in crosswind flight operation. The electrically conducting tether is deployed from a ground s...

Morphing wings have a large potential to improve the overall aircraft performances, in a way like natural flyers do. By adapting or optimising dynamically the shape to various flight conditions, there are yet many unexplored opportunities beyond current proof-of-concept demonstrations. This review discusses the most prominent examples of morphing c...

In conventional aeroelastic analysis and optimisation methods for wing design, different geometries are used for the different steps in the process. Generally, a parametrised model is used to describe the shape of the geometry for the optimisation process. Subsequently, this model is converted into a structural and aerodynamic model for analysis pu...

This paper presents an extension of the simulation code ASWING to aeroelastic analysis of an airborne wind turbine. The device considered in this study consists of a tethered rigid wing with onboard-mounted wind turbines designed for wind energy harvesting in crosswind flight operation. The electrically conducting tether is deployed from a ground s...

Low-fidelity fluid–structure interaction model of flexible propeller blades is assessed by means of comparison with high-fidelity aeroelastic results. The low-fidelity model is based on a coupled extended blade-element momentum model and non-linear beam theory which were both implemented in Matlab. High-fidelity fluid–structure interaction analysis...

An analytical model to predict the fatigue life of a composite laminate is discussed. It is based on the method developed by Kassapoglou to predict fatigue failure. The analytical model calculates stresses in each ply using classical lamination theory, degrades the residual strength using the linear degradation law and predicts failure based on Tsa...