scholarly journals Numerical study of wave attenuation by mass of rising bubbles

2019 ◽  
Author(s):  
Mojtaba Shegeft ◽  
Madjid Ghodsi Hassanabad ◽  
Mojtaba Ezam
Keyword(s):  
Wave Attenuation ◽  
Numerical Study

Numerical Study on Wave Attenuation of Tsunami-Like Wave by Emergent Rigid Vegetation

2021 ◽  
pp. 1-28
Author(s):  
K. Qu ◽  
G. Y. Lan ◽  
S. Kraatz ◽  
W. Y. Sun ◽  
B. Deng ◽  
...  
Keyword(s):  
Solitary Waves ◽  
Wave Energy ◽  
Wave Attenuation ◽  
Tsunami Wave ◽  
Numerical Study ◽  
Wave Model ◽  
Indian Ocean Tsunami ◽  
Vegetation Density ◽  
Rigid Vegetation ◽  
Total Wave

The extreme surges and waves generated in tsunamis can cause devastating damages to coastal infrastructures and threaten the intactness of coastal communities. After the 2004 Indian Ocean tsunami, extensive physical experiments and numerical simulations have been conducted to understand the wave attenuation of tsunami waves due to coastal forests. Nearly all prior works used solitary waves as the tsunami wave model, but the spatial-temporal scales of realistic tsunamis differ drastically from that of solitary waves in both wave period and wavelength. More recent work has questioned the applicability of solitary waves and been looking towards more realistic tsunami wave models. Therefore, aiming to achieve more realistic and accurate results, this study will use a parameterized tsunami-like wave based on wave observations during the 2011 Japan tsunami to study the wave attenuation of a tsunami wave by emergent rigid vegetation. This study uses a high-resolution numerical wave tank based on the non-hydrostatic wave model (NHWAVE). This work examines effects of prominent factors, such as wave height, water depth, vegetation density and width, on the wave attenuation efficiency of emergent rigid vegetation. Results indicate that the vegetation patch can dissipate a considerable amount of the total wave energy of the tsunami-like wave. However, the tsunami-like wave has a higher total wave energy, but also a lower wave energy dissipation rate. Results show that using a solitary instead of a tsunami-like wave profile can overestimate the wave attenuation efficiency of the coastal forest.

Numerical Investigation of Compression Wave Attenuation in Water Barriers

2015 ◽  
Vol 756 ◽  
pp. 491-494
Author(s):  
A.E. Baganina ◽  
D.Y. Paleev ◽  
Mikhail Yu. Blaschuk
Keyword(s):  
Numerical Investigation ◽  
Compression Wave ◽  
Wave Attenuation ◽  
Numerical Study ◽  
The Impact

The article presents the results of a numerical study of the compression wave attenuation (CW) in water barriers. The impact of barriers thickness, their quantity and concentration of water particles in the barrier have been analyzed in the process of CW attenuation.

Comparison of 2-D numerical viscoelastic waveform modeling with ultrasonic physical modeling

Geophysics ◽  
1996 ◽  
Vol 61 (3) ◽  
pp. 862-871 ◽  
Author(s):  
Genmeng Chen
Keyword(s):  
Physical Model ◽  
Physical Modeling ◽  
Wave Attenuation ◽  
Numerical Study ◽  
Solid Model ◽  
Viscoelastic Materials ◽  
Standard Linear Solid Model ◽  
Standard Linear Solid ◽  
Standard Linear ◽  
Voigt Model

The objective of the study is to test the validity of theoretical models of wave attenuation by comparing their predictions of attenuation against physical model results. The study is confined to a 2-D geometry, and the viscoelastic materials used in physical modeling are those commonly used in the experiment. The physical modeling data of homogeneous media are compared with the numerical results in the frequency domain. The time‐domain comparisons between numerical modeling and physical modeling are also shown by three examples. The theoretical viscoelastic models used in the numerical study are the Kelvin‐Voigt model, the standard linear solid model, and the standard linear solid model with a continuous spectrum of relaxation time. On the comparison of a single model, all the models simulate the physical model fairly well, but the standard linear solid model gives the best result among them. The Kelvin‐Voigt model is easy to use as a quick first‐order simulation of the viscoelastic materials because it has fewer viscosity parameters than the other two models. The disadvantage of the Kelvin‐Voigt model is that it predicts too much attenuation of the high‐frequency components. It is also shown that neglecting the viscosity of some materials like polyvinylcloride plastic (PVC), which has high viscosity, will produce incorrect results in synthetic seismograms.

Numerical study on wave attenuation inside and around a square array of biofouled net cages

2017 ◽  
Vol 78 ◽  
pp. 180-189 ◽  
Author(s):  
Chun-Wei Bi ◽  
Yun-Peng Zhao ◽  
Guo-Hai Dong ◽  
Tiao-Jian Xu ◽  
Fu-Kun Gui
Keyword(s):  
Wave Attenuation ◽  
Numerical Study ◽  
Net Cages ◽  
Square Array

Shock Wave Propagation Into a Dust-Gas Suspension Inside a Double-Bend Conduit

2002 ◽  
Vol 124 (2) ◽  
pp. 483-491 ◽  
Author(s):  
O. Igra ◽  
X. Wu ◽  
G. Q. Hu ◽  
J. Falcovitz
Keyword(s):  
Shock Wave ◽  
Wave Attenuation ◽  
Numerical Study ◽  
Effective Means ◽  
Solid Particles ◽  
Dust Particles ◽  
Mass Loading ◽  
Shock Attenuation ◽  
Dust Mass ◽  
Transmitted Shock Wave

Using conduits in which a transmitted shock wave experiences abrupt changes in its direction of propagation is an effective means for shock wave attenuation. An additional attenuation of the transmitted shock wave is obtained when the medium contained inside the conduit (through which the shock wave is transmitted) is a suspension rather than a pure gas. The present numerical study shows that adding small solid particles (dust) into the gaseous phase results in sharp attenuation of all shock waves passing through the conduit. It is shown that the smaller the dust particles diameter is, the higher the shock attenuation becomes. Increasing the dust mass loading in the suspension also causes a quick attenuation. By proper choice of dust mass loading in the suspension, or the particles diameter, it is possible to ensure that the emerging wave from the conduit exit channel is a (smooth) compression wave, rather than a shock wave.

scholarly journals On the influence of viscosity and caustics on acoustic streaming in sessile droplets: an experimental and a numerical study with a cost-effective method

2017 ◽  
Vol 821 ◽  
pp. 384-420 ◽  
Author(s):  
A. Riaud ◽  
M. Baudoin ◽  
O. Bou Matar ◽  
J.-L. Thomas ◽  
P. Brunet
Keyword(s):  
Numerical Method ◽  
Flow Structure ◽  
Acoustic Waves ◽  
Wave Attenuation ◽  
Numerical Study ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming ◽  
Fluid Viscosity ◽  
Bulk Wave ◽  
Dimensionless Numbers

When an acoustic wave travels in a lossy medium such as a liquid, it progressively transfers its pseudo-momentum to the fluid, which results in a steady flow called acoustic streaming. This phenomenon involves a balance between sound attenuation and shear, such that the streaming flow does not vanish in the limit of vanishing viscosity. Hence, the effect of viscosity has long been ignored in acoustic streaming experiments. Here, we investigate the acoustic streaming in sessile droplets exposed to surface acoustic waves. According to experimental data, the flow structure and velocity magnitude are both strongly influenced by the fluid viscosity. We compute the sound wave propagation and hydrodynamic flow motion using a numerical method that reduces memory requirements via a spatial filtering of the acoustic streaming momentum source terms. These calculations agree qualitatively well with experiments and reveal how the acoustic field in the droplet, which is dominated by a few caustics, controls the flow pattern. We evidence that chaotic acoustic fields in droplets are dominated by a few caustics. It appears that the caustics drive the flow, which allows for qualitative prediction of the flow structure. Finally, we apply our numerical method to a broader span of fluids and frequencies. We show that the canonical case of the acoustic streaming in a hemispherical sessile droplet resting on a lithium niobate substrate only depends on two dimensionless numbers related to the surface and bulk wave attenuation. Even in such a baseline configuration, we observe and characterize four distinct flow regimes.

Experimental and numerical study of shock wave attenuation at the outlet of two-dimensional and axisymmetric ducts

1993 ◽  
Vol 28 (4) ◽  
pp. 590-593 ◽  
Author(s):  
T. V. Bazhenova ◽  
S. B. Bazarov ◽  
O. V. Bulat ◽  
V. V. Golub ◽  
A. M. Schul'meister
Keyword(s):  
Shock Wave ◽  
Wave Attenuation ◽  
Numerical Study ◽  
Two Dimensional ◽  
Shock Wave Attenuation

Wave attenuation over porous seabeds: A numerical study

2017 ◽  
Vol 117 ◽  
pp. 28-40 ◽  
Author(s):  
Alec Torres-Freyermuth ◽  
Maurizio Brocchini ◽  
Sara Corvaro ◽  
Jose Carlos Pintado-Patiño
Keyword(s):  
Wave Attenuation ◽  
Numerical Study
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