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Lima Pereira, L.T. (author), Ragni, D. (author), Avallone, F. (author), Scarano, F. (author)The impact of aerodynamic loading on a serrated trailing edge is studied experimentally. Aerodynamic and acoustic measurements are conducted on a sawtooth-shaped trailing edge, retrofitted to a flat plate featuring a trailing-edge flap, and placed at incidence to the free-stream flow. The turbulent flow across the trailing edge is inspected...journal article 2022
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Fritz, E.K. (author), Ferreira, Carlos (author), Boorsma, Koen (author)<br/><br/>This article proposes an efficient correction model that enables the extension of the blade element momentum method (BEM) for swept blades. Standard BEM algorithms, assuming a straight blade in the rotor plane, cannot account for the changes in the induction system introduced by blade sweep. The proposed extension corrects the axial...journal article 2022
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Baldi, S. (author), Roy, Spandan (author), Yang, Kang (author), Liu, Di (author)Effective design of autopilots for fixed-wing unmanned aerial vehicles (UAVs) is still a great challenge, due to unmodeled effects and uncertainties that these vehicles exhibit during flight. Unmodeled effects and uncertainties comprise longitudinal/lateral cross-couplings, as well as poor knowledge of equilibrium points (trimming points) of...journal article 2022
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Candeloro, Paolo (author), Ragni, D. (author), Pagliaroli, Tiziano (author)In the last decade, the drone market has grown rapidly for both civil and military purposes. Due to their versatility, the demand for drones is constantly increasing, with several industrial players joining the venture to transfer urban mobility to the air. This has exacerbated the problem of noise pollution, mainly due to the relatively lower...journal article 2022
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Bento, Hugo F.M. (author), Ragni, D. (author), Avallone, F. (author), Simons, D.G. (author), Snellen, M. (author)Sound absorbing porous materials are used to line a wind tunnel wall, in order to reduce reflections. However, the lining can have a detrimental effect on the acoustic measurements due to an increase in the noise radiated from the walls. In addition, the aerodynamic fidelity of the tunnel can be affected. In the present study, the influence...journal article 2022
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Viré, A.C. (author), Lebesque, G.H.M. (author), Folkersma, M.A.M. (author), Schmehl, R. (author)Leading-edge inflatable (LEI) kites use a pressurized tubular frame to structurally support a single skin membrane canopy. The presence of the tubes on the pressure side of the wing leads to characteristic flow phenomena for this type of kite. In this paper, we present steady-state Reynolds-Averaged Navier-Stokes (RANS) simulations for a LEI...journal article 2022
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Romani, G. (author), Grande, E. (author), Avallone, F. (author), Ragni, D. (author), Casalino, D. (author)This paper presents a computational study of flow incidence effects on the aeroacoustics of a propeller operating at low blade-tip Mach numbers. The numerical flow solution is obtained by using the Lattice-Boltzmann/Very Large Eddy Simulation method, while far-field noise is computed through the Ffowcs-Williams & Hawkings' acoustic...journal article 2022
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van Sluis, M. (author), Nasrollahi, S. (author), Gangoli Rao, A. (author), Eitelberg, G. (author)The AeroCity is a new form of transportation concept that has been developed to provide high-speed ground transportation at a much lower cost than the existing high-speed railway. Utilizing the Wing-in-Ground (WIG) effect, the AeroCity vehicle does not require complex infrastructures like other contemporary concepts, such as the Hyperloop or...journal article 2022
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Aghajani, S. (author), Accardo, A. (author), Tichem, M. (author)One of the essential requirements to create nanoparticle (NP)-based applications and functions is the ability to control their deposition in specific locations. Many methods have been proposed, with wet direct writing (DW) techniques such as inkjet printing being the most employed. These methods generally depend on off-line and solvent-based...journal article 2022
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Zuo, Renwei (author), Li, Yinghui (author), Lv, Maolong (author), Liu, Zongcheng (author), Zhang, Fan (author)This article proposes an output-feedback fixed-time trajectory tracking control methodology for hypersonic flight vehicles subject to asymmetric output constraints. In contrast to the state of the art, the most distinguishing feature of our control design lies in avoiding using conventional recursive design methods (e.g., backstepping...journal article 2022
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Sun, B. (author), Mkhoyan, T. (author), van Kampen, E. (author), De Breuker, R. (author), Wang, Xuerui (author)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...journal article 2022
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Wang, X. (author), Roy, Spandan (author), Fari, S. (author), Baldi, S. (author)The high maneuverability of fixed-wing unmanned aerial vehicles (UAVs) exposes these systems to several dynamical and parametric uncertainties, severely affecting the fidelity of modeling and causing limited guidance autonomy. This article shows enhanced autonomy via adaptation mechanisms embedded in the guidance law: a vector-field method is...journal article 2022
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Dong, J. (author), Viré, A.C. (author)The rotor of floating offshore wind turbines with platform motions may undergo different working states during its operation, e.g. from windmill working state to vortex ring and propeller working state. In this paper, an aerodynamic model based on a free wake vortex method is used to simulate the rotor undergoing surge motion. The associated...journal article 2022
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Gonzalez Silva, J. (author), Ferrari, Riccardo M.G. (author), van Wingerden, J.W. (author)Wind turbine (WT) controllers are often geared towards maximum power extraction, while suitable operating constraints should be guaranteed such that WT components are protected from failures. Control strategies can be also devised to reduce the generated power, for instance to track a power reference provided by the grid operator. They are...conference paper 2022
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Li, Peng (author), Liu, Di (author), Xia, Xin (author), Baldi, S. (author)The operation of Unmanned Aerial Vehicles (UAVs) is often subject to state-dependent alterations and unstructured uncertainty factors, such as unmodelled dynamics, environmental weather disturbances, aerodynamics gradients, or changes in inertia and mass due to payloads. While a large number of autopilot solutions have been proposed to operate...conference paper 2022
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van Nesselrooij, M. (author), van Campenhout, O.W.G. (author), van Oudheusden, B.W. (author), Schrijer, F.F.J. (author), Veldhuis, L.L.M. (author)Accurately measuring small changes in aerodynamic drag over a flat surface stands at the core of the development of technologies capable of reducing turbulent friction drag. A wind tunnel drag measurement system was developed which improves significantly on the state of the art. Experimental tests demonstrated that an uncertainty of less than...journal article 2022
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Gonzalez Silva, J. (author), van der Hoek, D.C. (author), Mulders, S.P. (author), Ferrari, Riccardo M.G. (author), van Wingerden, J.W. (author)Wind turbines are prone to structural degradation, particularly in offshore locations. Based on the structural health condition of the tower, power de-rating strategies can be used to reduce structural loads at the cost of power losses. This paper introduces a novel closed-loop switching control architecture to constrain the thrust in individual...conference paper 2022
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Dsouza, Brian (author)Wind turbine power output has grown massively over the past few decades, and this has been achieved in part by increasing the size of rotors. But the size of rotors is now limited by structural constraints as well as space constraints in wind farms. It is therefore important to use other innovative methods to increase wind turbine capacity...master thesis 2021
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Uritsky, Vadim (author)Due to the increasing interest in modelling floating offshore wind turbines, simulation tools need to be adapted from fixed-base applications to surge applications. In this study, an open-source inviscid 3D panel method named Vortexje was adapted for surge motion and its ability to capture the physics of severe surge motion (when the rotor...master thesis 2021
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Ruland, Oscar (author)Recent trends in aviation highlight the ever-increasing need for fuel economy and sustainability. Active morphing technology can offer significant benefits over conventional wing designs. 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...master thesis 2021