Searched for: subject%3A%22Aerodynamics%22
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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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Mertens, C. (author), Costa Fernandez, J.L. (author), Sodja, J. (author), Sciacchitano, A. (author), van Oudheusden, B.W. (author)
The aeroelastic response of a highly flexible wing to periodic gust excitation is determined experimentally. The integrated optical measurement approach that is applied provides combined measurements of the structural response of the wing and the unsteady flow field around it. The aeroelastic loads acting on the wing are derived from these...
conference paper 2022
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Fehrs, Michael (author), Ritter, Markus (author), Helm, Sebastian (author), Mertens, C. (author)
The Pazy Wing test case is a benchmark for the investigation of aeroelastic effects at very large deflections. Tip deformations in the order of 50% span were measured in wind tunnel tests, which renders this model highly attractive for the validation of numerical aeroelastic methods and tools for geometrically nonlinear, large deflection...
conference paper 2022
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Su, Zikang (author), Wang, X. (author), Wang, Honglun (author)
This article contrives a neural-adaptive constrained controller of the cable towed air-ground recovery system subject to terrain obstacles, unmeasurable cable tensions, trailing vortex, wind gust, and actuator saturation. In air-ground recovery system modeling, the towed vehicle's nominal 6 DOF affine nonlinear dynamics and the cable system's...
journal article 2022
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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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Mehta, Piyush M. (author), Paul, Smriti N. (author), Crisp, Nicholas H. (author), Sheridan, Philip L. (author), Siemes, C. (author), March, G. (author), Bruinsma, Sean (author)
Satellite drag modeling remains the largest source of uncertainty affecting space operations in low Earth orbit. The uncertainty stems from inaccurate models for mass density and drag coefficient. Drag coefficient modeling also impacts scientific knowledge on the physics and dynamics of the upper atmosphere through the estimation of high...
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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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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Mourão Bento, H.F. (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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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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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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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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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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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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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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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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Lv, Maolong (author), Li, Yongming (author), Pan, W. (author), Baldi, S. (author)
This article proposes a fuzzy adaptive design solving the finite-time constrained tracking for hypersonic flight vehicles (HFVs). Actuator dynamics and asymmetric time-varying constraints are considered when solving this problem. The main features of the proposed design lie in 1) introducing a novel piecewise but differentiable switching...
journal article 2022
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Dong, J. (author), Viré, A.C. (author), Li, Zhangrui (author)
In our previous study, the vortex ring state (VRS) prediction criteria were introduced from helicopter's realm and applied to floating offshore wind turbines (FOWTs). The existence of the VRS on FOWTs was also successfully predicted. However, the prediction criteria we used have not been verified by comparing them with similar studies because...
journal article 2022
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Zhang, Boyang (author), Sun, Xiuxia (author), Liu, Shuguang (author), Lv, Maolong (author), Deng, Xiongfeng (author)
In contrast with most existing results concerning unmanned aerial vehicles (UAVs) wherein two-degree or only attitude/longitudinal dynamics are considered, this article proposes an event-triggered cooperative synchronization fault-tolerant control (FTC) methodology for multiple fixed-wing UAVs whose dynamics are six-degree-of-freedom (DOF)...
journal article 2022
Searched for: subject%3A%22Aerodynamics%22
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