Searched for: author:"Avallone, F."
(1 - 20 of 36)

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Casalino, D. (author), Avallone, F. (author), Gonzalez-Martino, Ignacio (author), Ragni, D. (author)
The effect of sinusoidal serrations applied to the leading-edge of the vanes of a realistic fan stage is investigated using high-fidelity numerical simulations. The CFD solver PowerFLOW based on a hybrid lattice-Boltzmann/very-large-eddy-simulation model is used to compute the unsteady flow and radiated noise of the 22-in source diagnostic...
journal article 2019
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Ragni, D. (author), Avallone, F. (author), van der Velden, W.C.P. (author), Casalino, D. (author)
Abstract: Pressure fluctuations on the suction side of a NACA 0018 with trailing-edge add-ons are obtained from integration of time-resolved stereoscopic and tomographic particle image velocimetry data and compared to the ones computed from Lattice–Boltzmann simulations. The airfoil is retrofitted with solid and slitted serrated trailing...
journal article 2019
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Avallone, F. (author), Casalino, D. (author), Ragni, D. (author)
A computational study of two Diffuser-Augmented Wind Turbines (DAWTs) is carried out to investigate both the hydrodynamic flow field and the far-field noise. The two configurations differ for the tip-clearance ratio, defined as the ratio between the tip clearance and the rotor radius. The DonQi® wind turbine, a three blades ducted rotor, is...
conference paper 2019
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Rubio Carpio, A. (author), Merino Martinez, R. (author), Avallone, F. (author), Ragni, D. (author), Snellen, M. (author), van der Zwaag, S. (author)
The hydrodynamic and acoustic fields for a NACA 0018 with solid and porous trailing edge inserts are investigated. The porous inserts, covering 20% of the chord, are manufactured with metal foams with cell diameters of 450 and 800 μm and permeability values of 6 × 10−10 and 2.7 × 10−9 m2. The experiments are performed at a chord-based Reynolds...
journal article 2019
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Falcão Loureiro Rêgo, L. (author), Avallone, F. (author), Ragni, D. (author), Casalino, D. (author)
A numerical investigation on jet-installation noise is performed using a software based on the Lattice-Boltzmann Method. A flat plate is placed in the irrotational hydrodynamic field of the jet, i.e. outside of the plume, resulting in noise increase due to the scattering of instability waves at the plate trailing edge. The configuration adopted...
conference paper 2019
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Avallone, F. (author), Casalino, D. (author), Ragni, D. (author)
This manuscript describes an aeroacoustic computational study on the impingement of a tractor-propeller slipstream on the leading edge of a pylon. Both the flow and acoustic fields are studied for two pylon leading edges: a solid and a flow-permeable one. The computational set-up replicates experiments performed at Delft University of...
journal article 2018
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Avallone, F. (author), van der Velden, W.C.P. (author), Ragni, D. (author), Casalino, D. (author)
Trailing-edge serrations are add ons retrofitted to wind-turbine blades to mitigate turbulent boundary-layer trailing-edge noise. This manuscript studies the physical mechanisms behind the noise reduction by investigating the far-field noise and the hydrodynamic flow field. A conventional sawtooth and a combed-sawtooth trailing-edge serration...
journal article 2018
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Dighe, V.V. (author), De Oliveira Andrade, G.L. (author), Avallone, F. (author), van Bussel, G.J.W. (author)
This paper aims to study the aerodynamic performance of ducted wind turbines (DWT) using inviscid and viscous flow calculations by accounting for the mutual interaction between the duct and the rotor. Two generalized duct cross section geometries are considered while the rotor is modelled as an actuator disc with constant thrust coefficient....
journal article 2018
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Tang, J. (author), Avallone, F. (author), Bontempo, R. (author), van Bussel, G.J.W. (author), Manna, M. (author)
This paper reports an experimental investigation on the effect of the duct geometry on the aerodynamic performance of an aerofoil shaped ducted wind turbine (DWT). The tested two-dimensional model is composed of an aerofoil equipped with pressure taps and a uniform porous screen. The experimental setup is based on the assumption that the duct...
journal article 2018
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Schneiders, J.F.G. (author), Avallone, F. (author), Pröbsting, S. (author), Ragni, D. (author), Scarano, F. (author)
The power spectral density and coherence of temporal pressure fluctuations are obtained from low-repetition-rate tomographic PIV measurements. This is achieved by extension of recent single-snapshot pressure evaluation techniques based upon the Taylor’s hypothesis (TH) of frozen turbulence and vortex-in-cell (VIC) simulation. Finite time...
journal article 2018
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Sinnige, T. (author), de Vries, R. (author), Della Corte, Biagio (author), Avallone, F. (author), Ragni, D. (author), Eitelberg, G. (author), Veldhuis, L.L.M. (author)
An experimental analysis was performed of the unsteady aerodynamic loading caused by the impingement of a propeller slipstream on a downstream lifting surface. When installed on an aircraft, this unsteady loading results in vibrations that are transmitted to the fuselage and are perceived inside the cabin as structure-borne noise. A pylon...
journal article 2018
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Merino Martinez, R. (author), Sanders, Martinus P.J. (author), Caldas, Luciano C. (author), Avallone, F. (author), Ragni, D. (author), de Santana, Leandro D. (author), Snellen, M. (author), Simons, D.G. (author)
Microphone arrays are useful measurement devices for estimating the location and strength of sound sources. Numerous comparative studies have been conducted regarding the performance of acoustic imaging methods in the past, but literature lacks of a systematic investigation on the role of the hardware on the measurements. This research...
conference paper 2018
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Raiola, M. (author), Discetti, Stefano (author), Ianiro, A. (author), Samara, F. (author), Avallone, F. (author), Ragni, D. (author)
. The model is equipped with 24 differential...
journal article 2018
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Rubio Carpio, A. (author), Avallone, F. (author), Ragni, D. (author)
and an angle of attack of 0°....
conference paper 2018
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González, G. (author), Ragni, D. (author), Avallone, F. (author), Schneiders, J.F.G. (author), Casalino, D. (author), Ianiro, A. (author)
The analysis of the unsteady flow field of an axisymmetric subsonic jet at Reynolds numbers between 5,000 and 20,000 and computation of its unsteady pressure field is carried out from single snapshots of tomographic PIV measurements (acquisition rate 0.8 Hz). This is achieved by a recently developed pressure-evaluation technique based upon...
conference paper 2018
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Arce Leon, C.A. (author), Merino Martinez, R. (author), Ragni, D. (author), Avallone, F. (author), Scarano, F. (author), Pröbsting, S. (author), Snellen, M. (author), Simons, D.G. (author), Madsen, Jesper (author)
The broadband noise generated by the scattering of turbulent flow at the trailing edge of a NACA 0018 airfoil with trailing edge serrations is investigated, varying both the airfoil angle of attack and serration flap angle. Acoustic emissions from the trailing edge are measured using a microphone array. The noise level is observed to be...
journal article 2017
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Arce Leon, C.A. (author), Merino Martinez, R. (author), Pröbsting, S. (author), Ragni, D. (author), Avallone, F. (author)
The trailing edge of a NACA 0018 airfoil is modified through the attachment of serrations with different degrees of permeability. Acoustic beamforming is used to inspect the turbulent boundary layer-trailing edge noise emissions from the unmodified and serrated trailing edges. Different freestream velocities and angles of attack are investigated...
journal article 2017
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Ragni, D. (author), Avallone, F. (author), van der Velden, W.C.P. (author)
The far-field noise and flow field of a novel curved trailing-edge serration (i.e. iron-shaped) are investigated. Spectra of the far-field broadband noise, directivity plots and the flow-field over the iron-shaped serration are obtained from numerical computations performed using a compressible Lattice-Boltzmann solver. The new design is...
conference paper 2017
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Merino Martinez, R. (author), Rubio Carpio, A. (author), Avallone, F. (author), Ragni, D. (author), Snellen, M. (author), van der Zwaag, S. (author)
conference paper 2017
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de Vries, R. (author), Sinnige, T. (author), Della Corte, Biagio (author), Avallone, F. (author), Ragni, D. (author), Eitelberg, G. (author), Veldhuis, L.L.M. (author)

conference paper 2017
Searched for: author:"Avallone, F."
(1 - 20 of 36)

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