Temat: waves - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Pressure field in a plane layer
Autorzy:: Baranowska, A.
Tematy:: acoustic waves propagation
acoustic waves
waves generation; Pokaż więcej
Wydawca:: Polskie Towarzystwo Akustyczne
Powiązania:: https://bibliotekanauki.pl/articles/331904.pdf Link otwiera się w nowym oknie
Opis:: The paper presents results of analytical and numerical investigations of a plane acoustic waves propagation through a plane layer surrounded by another medium. The waves generation problem is discussed. The mathematical model of the pressure propagation in the layer is proposed. Propagated through the layer changes in pressure, the reflected and transmitted waves were studied. Some results of numerical investigations are presented.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Generation and propagation of nonlinear waves in a towing tank
Autorzy:: Drzewiecki, Marcin
Sulisz, Wojciech
Tematy:: wavemaker
towing tank
nonlinear waves
waves generation
waves propagation; Pokaż więcej
Wydawca:: Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Powiązania:: https://bibliotekanauki.pl/articles/260177.pdf Link otwiera się w nowym oknie
Opis:: The paper presents the results of the research focused on linear and nonlinear wave generation and propagation in a deepwater towing tank equipped with a single flap-type wavemaker of variable draft. The problem of wave generation and propagation has been theoretically formulated and solved by applying an analytical method; linear and nonlinear solutions were obtained. The linear solution has been verified experimentally. The laboratory experiments confirmed that a linear model can be applied to predict the generation and propagation of water waves of low steepness. However, according to the analysis, the discrepancies between wave profiles predicted by applying the linear and nonlinear models rapidly increases with increasing wave steepness. Additionally, the secondary phenomena which occur in the towing tank, including: disintegration of wave profile, wave reflections from the beach and wave damping, were analyzed. Knowledge on the nonlinear processes and phenomena is essential for modeling the environmental conditions during tests carried out to secure the safety of the naval and offshore constructions. The theoretical formulation was derived and the solution was obtained by the Institute of Hydroengineering of the Polish Academy of Sciences IBW PAN while the experimental research was carried out in Ship Hydromechanics Division of the Ship Design and Research Centre CTO S.A.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: Scattering of plane acoustic waves at elastic particles with rough surfaces
Autorzy:: Bjørnø, L.
Tematy:: ultrasonic waves
acoustic waves
rough surfaces; Pokaż więcej
Wydawca:: Polskie Towarzystwo Akustyczne
Powiązania:: https://bibliotekanauki.pl/articles/332313.pdf Link otwiera się w nowym oknie
Opis:: A comprehensive theoretical and numerical study oj the influence oj surface roughness oj elastic particles in water on the scattering oj ultrasonic waves has been carried out. For near spherical shape oj the particles and with small rms-roughness heights a perturbation method has been developed. In this method the first-order perturbation contribution predicts the contribution to the incoherently scattered acoustic field due to surjace roughness, and the second-order perturbation contribution predicts the change in the coherent field and will satisfy the requirement oj energy conservation. The second-order perturbation contribution is evaluated using the concept ojform function, while the first-order perturbation to the total scattered acoustic field is evaluated using the scattering cross-section. As a junction oj the ka-value and jor different rms-roughness heights a numerical study oj the jorward and backward scattering from rough, elastic particles has been carried out and a substantial roughness influence on the scattered field has been verified. Same experimental resultsfrom measurements oj scattering jrom glass and cast iron spheres have given evidence to the numerical predictions.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 4.

Tytuł:: Sound waves in a wave noise
Autorzy:: Murawski, K.
Tarnowski, M.
Tematy:: sound waves
random waves
frequency shift
amplitude alteration; Pokaż więcej
Wydawca:: Politechnika Gdańska
Powiązania:: https://bibliotekanauki.pl/articles/1955702.pdf Link otwiera się w nowym oknie
Opis:: We examine by analytical and numerical means sound waves which propagate in a space- and time-dependent random mass density field in the form of dispersionless wave noise of its spectrum E(kappa,omega) ~ E(kappa) delta (omega-crk), where cr is a random speed. Numerical simulations are in agreement with the analytical theory which shows that at cr=omega/k resonance occurs and the cyclic frequency omega tends to infinity. For values of cr which are close to the resonance point, the sound waves are slowed down and attenuated (accelerated and amplified) for cr < omega/k (cr > omega/k).
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 5.

Tytuł:: Numerical simulations of sound wave generation in a random medium
Autorzy:: Murawski, K.
Selwa, M.
Tematy:: sound waves
random waves
frequency shift
amplitude alteration; Pokaż więcej
Wydawca:: Politechnika Gdańska
Powiązania:: https://bibliotekanauki.pl/articles/1955700.pdf Link otwiera się w nowym oknie
Opis:: In turbulent media, both sound wave sources and the speed of sound can be stochastic variables. By means of numerical simulations of one-dimensional Euler equations with random source terms we have studied two cases in a homogeneous stochastic random medium for which the speed of sound and sound sources are: (1) correlated and (2) uncorrelated. The numerical simulations indicate that, if the source and the speed of sound fluctuations are uncorrelated, the acoustic field is incoherent, with a zero expectation value. The mean field is non-zero in the correlated case. The correlated and uncorrelated cases are clearly distinguishable by the mean field, but also - to some extent - in the power spectrum, which displays a modified Lorentzian profile with a shift in frequency.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: Search for gravitational waves emitted from SN 2023ixf
Autorzy:: Kubisz, Jerzy
Współwytwórcy:: Współautorami artykułu są członkowie LIGO Scientific Collaboration, Virgo Collaboration, KAGRA Collaboration w liczbie 1778
Opis:: We present the results of a search for gravitational-wave transients associated with core-collapse supernova SN 2023ixf, which was observed in the galaxy Messier 101 via optical emission on 2023 May 19, during the LIGO–Virgo–KAGRA 15th Engineering Run. We define a five-day on-source window during which an accompanying gravitational-wave signal may have occurred. No gravitational waves have been identified in data when at least two gravitational-wave observatories were operating, which covered ∼14% of this five-day window. We report the search detection efficiency for various possible gravitational-wave emission models. Considering the distance to M101 (6.7 Mpc), we derive constraints on the gravitational-wave emission mechanism of core-collapse supernovae across a broad frequency spectrum, ranging from 50 Hz to 2 kHz, where we assume the gravitational-wave emission occurred when coincident data are available in the on-source window. Considering an ellipsoid model for a rotating proto-neutron star, our search is sensitive to gravitational-wave energy 1 $\times$ 10$^{−4}$ M$_{⊙}$c$^{2}$ and luminosity 2.6 $\times$ 10$^{−4}$ M$_{⊙}$c$^{2}$ s$^{−1}$ for a source emitting at 82 Hz. These constraints are around an order of magnitude more stringent than those obtained so far with gravitational-wave data. The constraint on the ellipticity of the proto-neutron star that is formed is as low as 1.08, at frequencies above 1200 Hz, surpassing past results.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

Artykuł

na półce

Skocz do pozycji: 7.

Tytuł:: An application of critically refracted longitudinal ultrasonic subsurface waves (LCR) to industrial nondestructive testing of thin walled pipe shaped elements of shock absorbers, axle shafts and transmission shafts
Autorzy:: Bicz, A.
Bicz, W.
Korzeniowski, M.
Ambroziak, A.
Tematy:: ultrasonic waves
subsurface waves
head waves
LCR
creeping waves
flaw detection in friction butt welds
MIAB welding
ultrasonic testing of thin walled pipes; Pokaż więcej
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Powiązania:: https://bibliotekanauki.pl/articles/114523.pdf Link otwiera się w nowym oknie
Opis:: The paper describes the application of critically refracted longitudinal ultrasonic subsurface waves (LCR, known also as lateral, creeping or head waves) to nondestructive flaw detection in friction welding or MAIB welded thin walled pipe shaped parts. The theory, a practical laboratory and industrial applications are presented.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Interaction of internal and surface waves in a two-layer fluid with free surface
Autorzy:: Naradovy, V.
Tematy:: internal waves
surface waves
fluid layer
multiple scales
stability; Pokaż więcej
Wydawca:: Fundacja na Rzecz Młodych Naukowców
Powiązania:: https://bibliotekanauki.pl/articles/115568.pdf Link otwiera się w nowym oknie
Opis:: The interaction of internal and surface waves in a two-layer fluid with free surface has been considered. The stability of wave packets propagation on the contact surface and free surface of hydrodynamic system „layer with rigid bottom - layer with free surface” was investigated. The amplitudes of the second harmonics of the elevations of the contact surface and the free surface are investigated.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: The interaction between local factors and the Convectively Coupled Equatorial Waves over Indonesia during the Western North Pacific and Australian monsoon phase
Autorzy:: Pramuwardani, Ida
Sunarto, Hartono
Sopaheluwakan, Ardhasena
Tematy:: Convectively Coupled Equatorial Waves
Kelvin waves
local factor
monsoon
Indonesia; Pokaż więcej
Wydawca:: Instytut Meteorologii i Gospodarki Wodnej - Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/108463.pdf Link otwiera się w nowym oknie
Opis:: A large scale perturbation by the Convectively Coupled Equatorial Waves (CCEW) is often observed in the tropics as a precursor to influence weather condition, for example over the Indonesian archipelago (Maritime Continent (MC)). This study examines the interaction between local factors and CCEW with regard to convection and vertical interferences on a local scale over Indonesia during extreme Western North Pacific (WNP) and Australian (AU) monsoon phases. Through space-time spectra analysis of a 15 year (2001-2015) Tropical Rainfall Measuring Mission (TRMM) 3B42 dataset, the propagation of CCEW, i.e. Kelvin, Equatorial Rossby (ER) and Mixing Rossby-Gravity (MRG) waves was assessed. An Empirical Orthogonal Function (EOF) 1 and 2 for each wave evolution across the region of Indonesia, was then compared with daily precipitation anomalies and multilevel wind observations from seven locations in Indonesia to assess the interaction between local factors and CCEW. Results suggest there is evidence of local convection associated with Kelvin waves in the afternoon through to the evening in Tangerang, Surabaya and Makassar during WNP monsoon phases. Local convection associated with MRG waves only occurred in Makassar at the last evolution day during the same period, while there is no clear evidence for an interaction between local factors for ER waves. Low-level westerly winds appear to be significantly coupled with convection from Kelvin waves in Tangerang, Surabaya, and Makassar during the WNP monsoon phase, while the interaction is less significant for MRG-coupled convections (except in Makassar during the same monsoon phase) and absent for ER waves. This study suggests that the global scale phenomena of the Kelvin wave is associated with local scale factors in controlling convection, particularly during an extreme WNP phase in Indonesia.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 10.

Tytuł:: Effects of liquid loadings on lamb waves in context of size dependent couple stress theory
Autorzy:: Sharma, V.
Kumar, S.
Tematy:: couple stress
characteristic length
Lamb waves
elastic waves
liquid loadings; Pokaż więcej
Wydawca:: Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:: https://bibliotekanauki.pl/articles/949331.pdf Link otwiera się w nowym oknie
Opis:: For understanding the effects of an internal microstructure, generalised microcontinuum theories with additional microstructural parameters are developed. One such a parameter, called the characteristic length of the material comparable with the internal cell size of the material is involved in the couple stress theory. The problem of propagation of Lamb waves in a plate with an internal microstructure and loaded with an inviscid liquid on both sides is studied using the couple stress theory. The dispersion equation of Lamb waves with the liquid loadings is derived. The impact of the liquid loadings is studied on the propagation of Lamb waves. The effect of the characteristic length is also studied on the phase velocity of Lamb waves in the plate for various modes in the presence of liquid loadings.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Informacja

Wyszukujesz frazę "waves" wg kryterium: Temat