Radiation from a Spherical Source Eccentrically Positioned in a Fluid Sphere

1972 ◽  
Vol 51 (1A) ◽  
pp. 81-82
Author(s):  
William Thompson
Keyword(s):  
Fluid Sphere ◽  
Spherical Source

COMPUTATION OF ACOUSTIC FIELD RADIATED BY A SPHERICAL SOURCE NEAR A THERMOVISCOUS FLUID SPHERE

2007 ◽  
Vol 15 (02) ◽  
pp. 159-180
Author(s):  
S. M. HASHEMINEJAD ◽  
A. H. PASDAR
Keyword(s):  
Acoustic Field ◽  
Acoustic Radiation ◽  
Conducting Fluid ◽  
Surface Velocity ◽  
Fluid Sphere ◽  
Spherical Source ◽  
Fluid Medium ◽  
Multiple Precision ◽  
Thermally Conducting ◽  
Thermoviscous Fluid

Acoustic radiation from a spherical source, vibrating with an arbitrary, axisymmetric, time-harmonic surface velocity distribution, while immersed near a thermoviscous fluid sphere suspended in an unbounded viscous thermally conducting fluid medium is computed. The formulation utilizes the appropriate wave field expansions and boundary conditions along with the translational addition theorem for spherical wave functions to develop a closed-form solution in form of infinite series. The prime objective is to investigate the thermoviscous loss effects on acoustic radiation and its associated field quantities. The analytical results are illustrated with a numerical example in which the spherical source, that may vibrate either in a monopole-like or a dipole-like mode, is suspended in a thermoviscous fluid medium near an equal-sized viscous thermally conducting fluid sphere. To avoid numerical difficulties normally arising in process of solving thermoviscous radiation/scattering problems in the frequency range of interest, a basic multiple precision FORTRAN computation package was utilized in developing specialized codes for computing special mathematical functions including spherical Bessel functions of complex argument and performing large complex matrix manipulations on floating point numbers of arbitrarily high precision. The essential acoustic field quantities such as the modal acoustic radiation impedance load on the source, the radiated far-field pressure directivity pattern and the radiated on-axis pressure are evaluated and discussed for representative values of the parameters characterizing the system. Limiting cases are examined and excellent agreements with well known solutions are attained.

Horizon-free gravitational collapse of radiating fluid sphere

2010 ◽  
Vol 331 (2) ◽  
pp. 645-650 ◽  
Author(s):  
Neeraj Pant ◽  
B. C. Tewari
Keyword(s):  
Gravitational Collapse ◽  
Fluid Sphere

scholarly journals An Oscillating Perfect-Fluid Sphere with Uniform Density

1968 ◽  
Vol 40 (5) ◽  
pp. 1184-1186 ◽  
Author(s):  
Kenji Tomita ◽  
Hidekazu Nariai
Keyword(s):  
Perfect Fluid ◽  
Fluid Sphere ◽  
Uniform Density
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