Numerical Simulation of Acoustic Wave Propagation in Cylindrical Fluid-Saturated Poroelastic Shell Immersed in Fluids

2011 ◽  
Vol 105-107 ◽  
pp. 127-131
Author(s):  
Wen Yang Gao ◽  
Qian Wu ◽  
Zhi Wen Cui ◽  
Kei Xie Wang ◽  
He Feng Dong
Keyword(s):  
Numerical Simulation ◽  
Cylindrical Shell ◽  
Wave Propagation ◽  
Acoustic Wave ◽  
Acoustic Pressure ◽  
Fluid Pressure ◽  
Longitudinal Mode ◽  
Stoneley Wave ◽  
Acoustic Wave Propagation ◽  
Full Waveform

Acoustic wave propagation in fluid-saturated porous cylindrical shell is investigated in this paper by using the Biot’s theory. The Expressions for acoustic pressure and radical displacement in and out fluid, the expressions for components of solid and filtration displacement and pore fluid pressure and stress tensor are given. The numerical simulation is operated on acoustic field in fluid of poroelastic cylindrical shell, and the full-waveform is obtained by Fourier transform, and acoustic pressure field in frequency-wavenumber domain is analyzed, as well as the influence of inner and outer radii on wave amplitude is discussed. It shows that if the thickness of shell remains constant, the amplitude of longitudinal mode increases and that of Stoneley wave decreases when inner and outer radii increasing. In the fast formation the influence of inner and outer radii on the amplitude of longitudinal mode is notable. In the slow formation the amplitude of Stoneley wave will decrease with inner and outer radii increasing.

Acoustic wave propagation in a fluid‐filled borehole surrounded by a formation with stress‐relief‐induced anisotropy

Geophysics ◽  
1993 ◽  
Vol 58 (9) ◽  
pp. 1257-1269 ◽  
Author(s):  
Lasse Renlie ◽  
Arne M. Raaen
Keyword(s):  
Wave Propagation ◽  
Acoustic Wave ◽  
Shear Wave ◽  
Transverse Isotropy ◽  
Shear Velocity ◽  
Stress Relief ◽  
Stoneley Wave ◽  
Acoustic Wave Propagation ◽  
Damaged Zone ◽  
Compressional Velocity

The stress relief associated with the drilling of a borehole may lead to an anisotropic formation in the vicinity of the borehole, where the properties in the radial direction differ from those in the axial and tangential directions. Thus, axial and radial compressional acoustic velocities are different, and similarly, the velocity of an axial shear‐wave depends on whether the polarization is radial or tangential. A model was developed to describe acoustic wave propagation in a borehole surrounded by a formation with stress‐relief‐induced radial transverse isotropy (RTI). Acoustic full waveforms due to a monopole source are computed using the real‐axis integration method, and dispersion relations are found by tracing poles in the [Formula: see text] plane. An analytic expression for the low‐frequency Stoneley wave is developed. The numerical results confirm the expectations that the compressional refraction is mainly given by the axial compressional velocity, while the shear refraction arrival is due to the shear wave with radial polarization. As a result, acoustic logging in an RTI formation, will indicate a higher [Formula: see text] ratio than that existing in the virgin formation. It also follows that the shear velocity may be a better indicator of a mechanically damaged zone near the borehole than the compressional velocity. The Stoneley‐wave velocity was found to decrease with the increasing degree of RTI.

Acoustic Wave Propagation in Standing Trees – Part 1. Numerical Simulation

2020 ◽  
Vol 52 (1) ◽  
pp. 53-72
Author(s):  
Fenglu Liu ◽  
Xiping Wang ◽  
Houjiang Zhang ◽  
Fang Jiang ◽  
Wenhua Yu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Wave Propagation ◽  
Acoustic Wave ◽  
Acoustic Wave Propagation ◽  
Standing Trees

Simulation of Noise Attenuation Using One and Two Degree of Freedom Helmholtz Resonators in Pipelines

2012 ◽  
Author(s):  
Maaz Farooqui ◽  
Samir Mekid
Keyword(s):  
Numerical Simulation ◽  
Wave Propagation ◽  
Acoustic Wave ◽  
Degrees Of Freedom ◽  
Design Procedure ◽  
Experimental Results ◽  
Noise Attenuation ◽  
Acoustic Wave Propagation ◽  
Helmholtz Resonators ◽  
Two Degree Of Freedom

Helmholtz resonators are known to be efficient resonators for ducts if they are properly designed. A design procedure is suggested in this paper to identify the size of the resonators in one and two degrees of freedom. The procedure is supported by a through numerical simulation of acoustic wave propagation that is presented and is verified using published experimental results. The overall procedure shows achievable great attenuation of noise in pipeline.

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