Temat: nonlinear acoustics - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Curves of thermodynamic states in some fluids with dispersion
Autorzy:: Perelomova, A.
Powiązania:: https://bibliotekanauki.pl/articles/1940694.pdf
Data publikacji:: 2017
Wydawca:: Politechnika Gdańska
Tematy:: equation of state
nonlinear acoustics
hysteresis
Opis:: Variations in the thermodynamic state of a dispersive medium, caused by sound, are studied. A bubbly liquid and a Maxwell fluid are considered as examples. Curves in the plane of thermodynamic states are plotted. They are in fact pictorial images of linear relations of excess pressure and excess density in the acoustic wave which reflect irreversible attenuation of the sound energy. The curves account for the nonlinear generation of the entropy mode in the field of sound. In the case of Maxwell fluids, loops may form under some conditions. Curves and loops for some kinds of stationary waveforms and impulse sound are discussed and compared.
Źródło:: TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2017, 21, 1; 53-64
1428-6394
Pojawia się w:: TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Nonlinear phenomena of small-scale sound in a gas with exponential stratification
Autorzy:: Perelomova, A.
Powiązania:: https://bibliotekanauki.pl/articles/1940705.pdf
Data publikacji:: 2017
Wydawca:: Politechnika Gdańska
Tematy:: sound propagation
non-uniform media
nonlinear acoustics
Opis:: The nonlinear dynamics of perturbations, quickly varying in space, with comparatively large characteristic wavenumbers k: k > 1/H, is considered. H is the scale of density and pressure reduction in unperturbed gas, as the coordinate increases (H is the so-called height of the uniform equilibrium gas). Coupling nonlinear equations which govern the sound and the entropy mode in a weakly nonlinear flow are derived. They describe the dynamics of the gas in the leading order, with an accuracy up to the terms k(H)-1. In the field of the dominative sound mode, other induced modes contain parts which propagate approximately with their own linear speeds and the speed of the dominative mode. The scheme of successive approximations of nonlinear links between perturbations in the progressive mode is established. The numerical calculations for some kinds of impulses confirm the theory.
Źródło:: TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2017, 21, 2; 135-147
1428-6394
Pojawia się w:: TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Nonlinear Excitation of the Non-Wave Perturbations by the Magnetoacoustic Waves in the Non-Isentropic Plasma
Autorzy:: Perelomova, A.
Powiązania:: https://bibliotekanauki.pl/articles/177449.pdf
Data publikacji:: 2018
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: magnetoacoustic waves
dynamics of plasma
nonlinear acoustics
Opis:: Nonlinear excitation of slow modes by the planar magnetosonic perturbations in a plasma is discussed. Plasma is an open system due to radiation and external heating. This may stipulate enhancement of wave perturbations and hence the acoustical activity of plasma. Plasma is assumed to be a homogeneous ideal gas with infinite electrical conductivity. The straight magnetic field is orthogonal to the velocity of fluid’s elements. Nonlinear excitation of the non-wave modes (that is, the Alfvén and the entropy modes) by periodic and aperiodic planar magnetoacoustic perturbations, is discussed. The sawtooth wave and the small-magnitude harmonic wave are considered as examples of periodic in time perturbations. The conclusions concern acoustically active and thermally unstable flows as well.
Źródło:: Archives of Acoustics; 2018, 43, 1; 21-29
0137-5075
Pojawia się w:: Archives of Acoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Studies of Nonlinear Sound Dynamics in Fluids Based on the Caloric Equation of State
Autorzy:: Perelomova, A.
Wojda, P.
Powiązania:: https://bibliotekanauki.pl/articles/177850.pdf
Data publikacji:: 2010
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: nonlinear acoustics
parameters of nonlinearity
equations of state
Riemann wave
Opis:: The sound speed and parameters of nonlinearity B/A, C/A in a fluid are expressed in terms of coefficients in the Taylor series expansion of an excess internal energy, in powers of excess pressure and density. That allows to conclude about features of the sound propagation in fluids, the internal energy of which is known as a function of pressure and density. The sound speed and parameters of nonlinearity in the mixture consisting of boiling water and its vapor under different temperatures, are evaluated as functions of mass concentration of the vapor. The relations analogous to that in the Riemann wave in an ideal gas are obtained in a fluid obeying an arbitrary equation of state. An example concerns the van der Waals gases. An excess pressure in the reflected wave, which appears when standard or nonlinear absorption in a fluid takes place, is evaluated in an arbitrary fluid.
Źródło:: Archives of Acoustics; 2010, 35, 4; 619-633
0137-5075
Pojawia się w:: Archives of Acoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 5.

Tytuł:: Features of Nonlinear Sound Propagation in Vibrationally Excited Gases
Autorzy:: Perelomova, A.
Kusmirek, M.
Powiązania:: https://bibliotekanauki.pl/articles/176608.pdf
Data publikacji:: 2013
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: nonlinear acoustics
parameter of nonlinearity
non-equilibrium media
vibrationally excited gas
Opis:: Weakly nonlinear sound propagation in a gas where molecular vibrational relaxation takes place is studied. New equations which govern the sound in media where the irreversible relaxation may take place are derived and discussed. Their form depends on the regime of excitation of oscillatory degrees of freedom, equilibrium (reversible) or non-equilibrium (irreversible), and on the comparative frequency of the sound in relation to the inverse time of relaxation. Additional nonlinear terms increase standard nonlinearity of the high-frequency sound in the equilibrium regime of vibrational excitation and decrease otherwise. As for the nonlinearity of the low-frequency sound, the conclusions are opposite. Appearance of a non-oscillating additional part which is a linear function of the distance from the transducer is an unusual property of nonlinear distortions of harmonic at the transducer high-frequency sound.
Źródło:: Archives of Acoustics; 2013, 38, 3; 357-362
0137-5075
Pojawia się w:: Archives of Acoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

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