scholarly journals Body waves in poroelastic media saturated by two immiscible fluids

1996 ◽  
Vol 101 (B11) ◽  
pp. 25149-25159 ◽  
Author(s):  
Kagan Tuncay ◽  
M. Yavuz Corapcioglu
Keyword(s):  
Immiscible Fluids ◽  
Body Waves ◽  
Poroelastic Media

Body Waves in Composite Solid Matrix Containing Two Immiscible Fluids

2015 ◽  
Vol 108 (3) ◽  
pp. 531-554 ◽  
Author(s):  
Ashish Arora ◽  
Abhishek Painuly ◽  
S. K. Tomar
Keyword(s):  
Immiscible Fluids ◽  
Body Waves ◽  
Solid Matrix ◽  
Composite Solid

FRACTAL WAVEFIELD ANALYSIS TO CHARACTERIZE GEOMETRIC PROPERTIES OF FRACTURED MEDIA

Fractals ◽  
2007 ◽  
Vol 15 (02) ◽  
pp. 127-138
Author(s):  
ALEXANDER DROUJININE ◽  
VLADIMIR ROK
Keyword(s):  
Homogeneous Medium ◽  
Wave Dispersion ◽  
Analytic Solutions ◽  
Body Waves ◽  
Fracture Detection ◽  
Fracture Characterization ◽  
Multi Scale ◽  
Poroelastic Media ◽  
Inverse Q Filtering ◽  
Dispersion And Attenuation

We have investigated wave scattering by chaotic fractured systems of fractal geometry with random spatial variation that causes energy loss of the directly propagated field. We have examined simple analytic solutions in fractal poroelastic media. These solutions may be characterized by their frequency-power-law (FPL) signature caused by wave dispersion and attenuation. It has been proved that medium memory effects cause smoothing of the wavefield in the vicinity of the wavefront and rapid amplitude decay far from the wavefront. It appears that finite-bandwidth signals are delayed with respect to the wavefront in comparable elastic media. To examine the FPL dependence of direct body waves propagating in a homogeneous medium containing fractal inhomogeneities, we compute acoustic finite-difference snapshots in the frequency range f = 20 - 200 Hz. Numerical results show that the fractal dimension can be estimated from the FPL dependence of the scattered wavefield. Applications to fracture characterization are considered. Results are important for multi-scale depth imaging, inverse Q filtering, fracture detection, and integrated geophysical reservoir monitoring.

scholarly journals Two-Phase Flow Effects on Seismic Wave Anelasticity in Anisotropic Poroelastic Media

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6528
Author(s):  
Juan Santos ◽  
José Carcione ◽  
Jing Ba
Keyword(s):  
Transversely Isotropic ◽  
Immiscible Fluids ◽  
Point Of View ◽  
General Point ◽  
Spatial Period ◽  
Two Phase ◽  
Porous Layers ◽  
Poroelastic Media ◽  
Flow Effects ◽  
Flow Interference

We study the wave anelasticity (attenuation and velocity dispersion) of a periodic set of three flat porous layers saturated by two immiscible fluids. The fluids are very dissimilar in properties, namely gas, oil, and water, and, at most, three layers are required to study the problem from a general point of view. The sequence behaves as viscoelastic and transversely isotropic (VTI) at wavelengths much longer than the spatial period. Wave propagation causes fluid flow and slow P modes, inducing anelasticity. The fluids are characterized by capillary forces and relative permeabilities, which allow for the existence of two slow modes and the presence of dissipation, respectively. The methodology to study the physics is based on a finite-element uspcaling approach to compute the complex and frequency-dependent stiffnesses of the effective VTI medium. The results of the experiments indicate that there is higher dissipation and anisotropy compared to the widely used model based on an effective fluid that ignores the effects of surface tension (capillarity) and viscous flow interference between the two fluid phases.

Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

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