Searched for: subject%3A%22Porous%255C%2Bmaterials%22
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Rubio Carpio, A. (author)
Permeable trailing edges are experimentally investigated in this thesis as a mean tomitigate aeroacoustic noise. The first part of the study is devoted to deciphering themechanisms of noise generation involved in these devices. To this aim, trailing-edge inserts are manufactured employing commercially-produced open-cell metallic foams with...
doctoral thesis 2021
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Zamponi, R. (author)
The interaction of an airfoil with incident turbulence is an important source of aerodynamic noise in numerous applications, such as turbofan engines, cooling systems for automotive and construction industries, high-lift devices on aircraft wings, and landing gear systems. In these instances, turbulence is generally produced by elements that are...
doctoral thesis 2021
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Teruna, C. (author), Avallone, F. (author), Casalino, D. (author), Ragni, D. (author)
A lattice-Boltzmann method has been employed to study the aeroacoustics and aerodynamics of airfoils equipped with leading edge treatments, namely the porous leading edge and leading edge serrations. The present study aims to identify the differences in noise reduction mechanisms between the two treatments. Within the context of...
journal article 2021
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Rego, Leandro (author), Ragni, D. (author), Avallone, F. (author), Casalino, D. (author), Zamponi, R. (author), Schram, Christophe (author)
This paper investigates the application of flow-permeable materials as a solution for reducing jet-installation noise. Experiments are carried out with a flat plate placed in the near field of a single-stream subsonic jet. The flat plate is modular and the solid surface near the trailing edge can be replaced with different flow-permeable...
journal article 2021
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Teruna, C. (author), Rego, Leandro (author), Avallone, F. (author), Ragni, D. (author), Casalino, D. (author)
Porous materials have been widely investigated as a mean for noise reduction. Numerical simulations can be used to investigate the physical mechanisms responsible for noise reduction; however, a correct modeling of the porous medium through an equivalent fluid model is essential to minimize the computational costs. This paper reports a...
journal article 2021
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Nunes, Cristiana (author), Maria Aguilar Sanchez, Asel (author), Godts, Sebastiaan (author), Gulotta, Davide (author), Ioannou, Ioannis (author), Lubelli, B. (author), Menendez, Beatriz (author), Shahidzadeh, Noushine (author), Slížková, Zuzana (author), Theodoridou, Magdalini (author)
The RILEM TC ASC-271 is developing a new laboratory test to assess the durability of porous building materials to salt crystallisation. The test encompasses two phases: salt accumulation and damage propagation. This paper focuses on designing a procedure for the accumulation phase; this is considered successful when salts crystallise at the...
journal article 2021
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Tamaro, Simone (author), Zamponi, R. (author), Ragni, D. (author), Teruna, C. (author), Schram, Christophe (author)
Abstract: The flow field on solid and porous airfoils subjected to turbulence shed by an upstream cylindrical rod and the corresponding far-field noise radiations are studied through particle image velocimetry (PIV) and microphone measurements, respectively. Three different Reynolds numbers based on the rod diameter are considered in a range...
journal article 2021
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Rubio Carpio, A. (author), Avallone, F. (author), Ragni, D. (author), Snellen, M. (author), van der Zwaag, S. (author)
An experimental study on broadband noise scattered by permeable trailing edges with different pore arrangements is performed. A NACA 0018 airfoil with chord c = 0.2 m is investigated at chord-based Reynolds numbers ranging from 1.4 × 10<sup>5</sup> to 3.8 × 10<sup>5</sup> and angles of attack of 0.2 and 5.4 degrees. Noise emission from five...
journal article 2020
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Zamponi, R. (author), Satcunanathan, S. (author), Moreau, S. (author), Ragni, D. (author), Meinke, M. (author), Schröder, W. (author), Schram, C. (author)
A possible strategy for the reduction of the aeroacoustic noise generated by turbulence interacting with a wing profile, also referred to as leading-edge noise, is represented by the implementation of a porous medium in the structure of the airfoil. However, the physical mechanisms involved in this noise mitigation technique remain unclear....
journal article 2020
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Mayer, Jonathan (author), Rubio Carpio, A. (author), Ragni, D. (author)
The present work analyses broadband noise scattering from permeable trailing edges with identical micro-structure but under a change of temperature. Experiments are performed in an anechoic wind tunnel using a NACA0018 airfoil at chord-based Reynolds numbers between 1.88 × 10<sup>5</sup> and 3.14 × 10<sup>5</sup> and no incidence. A...
journal article 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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Lubelli, B. (author), Cnudde, Veerle (author), Diaz-Goncalves, Teresa (author), Franzoni, Elisa (author), van Hees, R.P.J. (author), Ioannou, Ioannis (author), Menendez, Beatriz (author), Nunes, Cristiana (author), Siedel, Heiner (author), Stefanidou, Maria (author), Verges-Belmin, Veronique (author), Viles, Heather (author)
The durability of building materials with respect to salt crystallization is commonly determined by accelerated weathering tests, carried out in the laboratory. An effective laboratory weathering test should assess the durability and, in the case of conservation of historic buildings, the compatibility of repair materials with those existing....
journal article 2018
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Bavykina, A.V. (author)
This thesis focuses on the development of functional Porous Organic Frameworks (POFs) for various catalytic applications. POF supported molecular catalysts allow to combine the advantages of both homogeneous and heterogeneous catalysts, offering excellent prospects in the quest to heterogenize homogeneous catalysts. The framework tunability of...
doctoral thesis 2017
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Van Dalen, K.N. (author), Drijkoningen, G.G. (author), Smeulders, D.M.J. (author)
Pseudo interface waves can exist at the interface of a fluid and a fluid-saturated poroelastic solid. These waves are typically related to the pseudo-Rayleigh pole and the pseudo-Stoneley pole in the complex slowness plane. It is found that each of these two poles can contribute (as a residue) to a full transient wave motion when the...
journal article 2010
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Yuan, C.A. (author), Van der Sluis, O. (author), Zhang, G.Q. (author), Ernst, L.J. (author), Van Driel, W.D. (author), Flower, A.E. (author), Van Silfhout, B.R. (author)
We propose an amorphous/porous molecular connection network generation algorithm for simulating the material stiffness of a low-k material (SiOC:H). Based on a given concentration of the basic building blocks, this algorithm will generate an approximate and large amorphous network. The molecular topology is obtained by distributing these blocks...
journal article 2008
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Wisse, C.J. (author), Smeulders, D.M.J. (author), Chao, G. (author), Van Dongen, M.E.H. (author)
The classical theory of wave propagation in elastic cylinders is extended to poro-elastic mandrel modes. The classical theory predicts the existence of undamped L modes and damped C, I, and Z modes. These waves also appear in poro-elastic mandrels, but all of them become damped because of viscous effects. The presence of the Biot slow bulk wave...
journal article 2007
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Yan, B. (author), Pham, H.T.M. (author), Ma, Y. (author), Zhuang, Y. (author), Sarro, P.M. (author)
The authors demonstrate a method for the fabrication of in situ ultrathin porous anodic aluminum oxide layers (aspect ratio<2:1) on Si, which can be directly used as templates for nanodot preparation and for pattern transfer. The regular shape of the aluminum oxide pores is maintained even when the thickness of the aluminum oxide template is...
journal article 2007
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Poesio, P. (author), Ooms, G. (author)
journal article 2007
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Huang, R.W.J.M. (author), Chung, F. (author), Kelder, E.M. (author)
We present a semimathematical model for the simulation of the impedance spectra of a rechargeable lithium batteries consisting of porous electrodes with spherical Li+ intercalation particles. The particles are considered to have two distinct homogeneous phases as a result of the intercalation and deintercalation of Li+ during charge and...
journal article 2006
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Chao, G. (author), Smeulders, D.M.J. (author), Van Dongen, M.E.H. (author)
Acoustic experiments on the propagation of guided waves along water-filled boreholes in water-saturated porous materials are reported. The experiments were conducted using a shock tube technique. An acoustic funnel structure was placed inside the tube just above the sample in order to enhance the excitation of the surface modes. A fast Fourier...
journal article 2006
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