Energy distribution and radiation loading of a cylindrical source suspended within a nonconcentric fluid cylinder

Hasheminejad, Seyyed M.; Azarpeyv, M.

doi:10.1007/s00707-003-0014-9

Cited by 9 publications

(6 citation statements)

References 19 publications

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“…8 of Ref. [26] (note that all curves are normalized with respect to the case in which the source is positioned at the center of the borehole). As a further check, we set e = 0 (i.e., a perfectly concentric source) to successfully reproduced all the numerical results presented in Refs.…”

Section: Numerical Resultsmentioning

confidence: 99%

“…Finally, in order to check overall validity of the calculations, we first filled the borehole cavity with 3M Company FC-72 [26], and applied the "all-fluid approximation [13]" to the water-saturated Ridgefield sandstone formation in order to compute the normalized on-axis farfield pressure amplitude, | p p (r 2 → ∞; θ 2 = π ; z = 0) |(10 −5 N/cm 2 ), versus the eccentricity parameter, e/b, for a small source vibrating at selected acoustic and structural frequencies (k z b = 0, π/2; kb = 20) by setting ρ 0 = 1, 680 g/cm 3 , c 0 = 51, 200 cm/s, a = 0.01 b = 0.1 cm and also, φ 0 1, α 0 = 1, η → 0, µ → 0, ρ s = ρ f l , K s = K f l in our general MATLAB code. The numerical results, as shown in Fig.…”

Section: Numerical Resultsmentioning

confidence: 99%

“…1), we shall express the cylindrical wave functions of the (r 1 , θ 1 , z) coordinate system in terms of cylindrical wave functions of the (r 2 , θ 2 , z) coordinate system through the application of the translational addition theorem for bicylindrical coordinates [25,26]:…”

Section: Wave Transformations and Boundary Conditionsmentioning

confidence: 99%

“…where Z = SR −1 is the so called acoustic radiation impedance matrix [26,27] whose elements on principal diameter represent the modal radiation (self-)impedance load on the vibrating cylindrical surface that can advantageously be written in terms of resistive and reactive components as [20] z nn (ω) = ρ 0 c 0 r nn (ω) − iρ 0 ωar nn (ω),…”

Section: Acoustic Radiation Impedancementioning

confidence: 99%

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Dynamic interaction of an eccentric multipole cylindrical radiator suspended in a fluid-filled borehole within a poroelastic formation

Hasheminejad

Miri

2007

Acta Mech Sin

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Acoustic radiation and the dynamic field induced by a cylindrical source of infinite extent, undergoing angularly periodic and axially-dependent harmonic surface vibrations, while eccentrically suspended in a fluid-filled cylindrical cavity embedded within a fluid-saturated porous elastic formation, are analyzed in an exact manner. This configuration, which is a realistic idealization of an acoustic logging tool suspended in a fluid-filled borehole within a permeable surrounding formation, is of practical importance with a multitude of possible applications in seismo-acoustics. The formulation utilizes the novel features of Biot dynamic theory of poroelasticity along with the translational addition theorem for cylindrical wave functions to obtain a closedform series solution. The basic dynamic field quantities such as the resistive and the reactive components of the modal acoustic radiation impedance load on the source in addition to the radial and transverse stresses induced in the surrounding formation by an eccentric pulsating/oscillating cylinder in a water-filled borehole within a water-saturated Ridgefield sandstone medium are evaluated and discussed. Special attention is paid to the effects of source eccentricity, excitation frequency, and mode of surface oscillations on the modal impedance values and the dynamic stresses. Limiting cases are considered and good agreements with available solutions are obtained.

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Section: Numerical Resultsmentioning

confidence: 99%

Section: Numerical Resultsmentioning

confidence: 99%

Section: Wave Transformations and Boundary Conditionsmentioning

confidence: 99%

Section: Acoustic Radiation Impedancementioning

confidence: 99%

See 2 more Smart Citations

Dynamic interaction of an eccentric multipole cylindrical radiator suspended in a fluid-filled borehole within a poroelastic formation

Hasheminejad

Miri

2007

Acta Mech Sin

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“…The convergence was systematically checked in a simple trail and error manner, by increasing the truncation constants (i.e., including higher number of modes) while looking for steadiness or stability in the numerical value of the solutions (see Fig. 13 in [41]). Furthermore, to check overall validity of the work we first computed the "two-cylinder gain" (see eq.…”

Section: Numerical Resultsmentioning

confidence: 99%

Acoustic diffraction by a pair of poroelastic cylinders

Hasheminejad

Avazmohammadi

2006

Z Angew Math Mech

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This study treats the interaction of a plane compressional sound wave with a cluster of two fluid-saturated porous elastic cylinders submerged in an unbounded acoustic medium. The novel features of Biot dynamic model for description of poroelastic material behaviour along with the appropriate wave field expansions, the pertinent boundary conditions, and the translational addition theorem for cylindrical wave functions are employed to develop a closed-form solution in the form of infinite series. The theoretical model was extended to consider the case of sound diffraction by a pair of absorbing cylinders with locally reacting or extended reaction boundaries. The analytical results are illustrated with numerical examples in which two identical air-saturated glass wool cylinders are insonified by a plane sound wave at end-on/broadside incidence. The most fundamental acoustic field quantity, namely, the scattering form function amplitude is evaluated and discussed for representative values of the parameters characterizing the system. The effects of incident wave frequency, angle of incidence, and proximity of the two cylinders are examined. Particular attention has been focused on multiple scattering interactions as well as the surface reaction modelling effects. Numerical comparison is made with the case of acoustic diffraction by a pair of absorbing cylinders with locally reacting or extended reaction boundaries. Limiting cases involving two rigid cylinders and also a pair of penetrable (fluid) cylinders are considered and good agreements with well-known solutions are established.

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Scattering and active acoustic control from a submerged piezoelectric-coupled orthotropic hollow cylinder

Hasheminejad¹,

Rajabi²

2008

Journal of Sound and Vibration

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Energy distribution and radiation loading of a cylindrical source suspended within a nonconcentric fluid cylinder

Cited by 9 publications

References 19 publications

Dynamic interaction of an eccentric multipole cylindrical radiator suspended in a fluid-filled borehole within a poroelastic formation

Dynamic interaction of an eccentric multipole cylindrical radiator suspended in a fluid-filled borehole within a poroelastic formation

Acoustic diffraction by a pair of poroelastic cylinders

Scattering and active acoustic control from a submerged piezoelectric-coupled orthotropic hollow cylinder

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