A reduced-order integral formulation to account for the finite size effect of isotropic square panels using the transfer matrix method

2016 ◽  
Vol 139 (4) ◽  
pp. 1773-1783 ◽  
Author(s):  
Paolo Bonfiglio ◽  
Francesco Pompoli ◽  
Riccardo Lionti
Keyword(s):  
Size Effect ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Finite Size ◽  
Integral Formulation ◽  
Finite Size Effect ◽  
Reduced Order

Computation of the Alpha Cabin Sound Absorption Coefficient by Using the Finite Transfer Matrix Method (FTMM): Inter-Laboratory Test on Porous Media

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Andrea Santoni ◽  
Paolo Bonfiglio ◽  
Patrizio Fausti ◽  
Francesco Pompoli
Keyword(s):  
Absorption Coefficient ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Sound Absorption ◽  
Finite Size ◽  
Sound Absorption Coefficient ◽  
Radiation Impedance ◽  
Simulation Based ◽  
Private Research

Abstract The transfer matrix method (TMM) has become an established and widely used approach to compute the sound absorption coefficient of a multilayer structure. Due to the assumption made by this method of laterally infinite media, it is necessary to introduce in the computation the finite-size radiation impedance of the investigated system, in order to obtain an accurate prediction of the sound absorption coefficient within the entire frequency range of interest; this is generally referred to as finite transfer matrix method (FTMM). However, it has not been extensively investigated the possibility of using the FTMM to accurately approximate the sound absorption of flat porous samples experimentally determined in an Alpha Cabin, a small reverberation room employed in the automotive industry. To this purpose, a simulation-based round robin test was organized involving academic and private research groups. Four different systems constituted by five porous materials, whose properties were experimentally characterized, were considered. Each participant, provided with all the mechanical and physical properties of each medium, was requested to simulate the sound absorption coefficient with an arbitrary chosen code, based on the FTMM. The results indicated a good accuracy of the different formulations to determine the finite-size radiation impedance. However, its implementation in the computation of the sound absorption coefficient as well as the upper limit of the range of incidence angles within which the acoustic field is simulated, and the model adopted to describe each material, significantly influenced the results.

The transfer matrix method for lattice proteins—an application with cooperative interactions

Polymer ◽  
2004 ◽  
Vol 45 (2) ◽  
pp. 707-716 ◽  
Author(s):  
Andrzej Kloczkowski ◽  
Taner Z. Sen ◽  
Robert L. Jernigan
Keyword(s):  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Cooperative Interactions ◽  
Lattice Proteins

scholarly journals Theoretical Investigation of the Size Effect on the Oxygen Adsorption Energy of Coinage Metal Nanoparticles

2021 ◽  
Author(s):  
Amir H. Hakimioun ◽  
Elisabeth M. Dietze ◽  
Bart D. Vandegehuchte ◽  
Daniel Curulla-Ferre ◽  
Lennart Joos ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Effect ◽  
Adsorption Energy ◽  
Single Point ◽  
Finite Size ◽  
Geometry Optimization ◽  
Oxygen Adsorption ◽  
Finite Size Effect ◽  
Full Geometry Optimization ◽  
Coinage Metal

AbstractThis study evaluates the finite size effect on the oxygen adsorption energy of coinage metal (Cu, Ag and Au) cuboctahedral nanoparticles in the size range of 13 to 1415 atoms (0.7–3.5 nm in diameter). Trends in particle size effects are well described with single point calculations, in which the metal atoms are frozen in their bulk position and the oxygen atom is added in a location determined from periodic surface calculations. This is shown explicitly for Cu nanoparticles, for which full geometry optimization only leads to a constant offset between relaxed and unrelaxed adsorption energies that is independent of particle size. With increasing cluster size, the adsorption energy converges systematically to the limit of the (211) extended surface. The 55-atomic cluster is an outlier for all of the coinage metals and all three materials show similar behavior with respect to particle size. Graphic Abstract

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