scholarly journals Geoacoustic inversion based on both acoustic pressure and particle velocity

2006 ◽  
Vol 120 (5) ◽  
pp. 3355-3356
Author(s):  
A. Vincent van Leijen ◽  
Jean‐Pierre Hermand ◽  
Kevin B. Smith
Keyword(s):  
Particle Velocity ◽  
Acoustic Pressure ◽  
Geoacoustic Inversion

Geoacoustic inversion based on particle velocity

2016 ◽  
Vol 139 (4) ◽  
pp. 2125-2125
Author(s):  
David R. Dall'Osto ◽  
Peter H. Dahl
Keyword(s):  
Particle Velocity ◽  
Geoacoustic Inversion

scholarly journals Acoustic Pressure and Particle Velocity for Spatial Filtering of Bottom Arrivals

2019 ◽  
Vol 44 (1) ◽  
pp. 179-192 ◽  
Author(s):  
Paulo Felisberto ◽  
Paulo Santos ◽  
Sergio M. Jesus
Keyword(s):  
Particle Velocity ◽  
Acoustic Pressure ◽  
Spatial Filtering

Flow-Excited Acoustic Resonance of Isolated Cylinders in Cross-Flow

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Nadim Arafa ◽  
Atef Mohany
Keyword(s):  
Particle Velocity ◽  
Acoustic Pressure ◽  
Excited Level ◽  
Cross Flow ◽  
Acoustic Resonance ◽  
Excitation Level ◽  
Linear Superposition ◽  
The Cross ◽  
Particle Velocities ◽  
Mode A

The flow-excited acoustic resonance of isolated cylinders in cross-flow is investigated experimentally where the effect of the cylinder(s) proximity to the acoustic particle velocity nodes of the cross-modes is presented in this paper. For the case of a single cylinder, the cylinder's location does not significantly affect the vortex shedding process; however, it affects the excitation level of each acoustic cross-mode. When the cylinder is moved away from the acoustic particle velocity antinode of a specific acoustic cross-mode, a combination of the cross-modes is excited with intensities that seem to be proportional to the ratio of the acoustic particle velocities of these modes at the cylinder's location. For the cases of two and three hydrodynamically uncoupled cylinders positioned simultaneously side-by-side in the duct, it is observed that the first three acoustic cross-modes are excited. When one cylinder is positioned at the acoustic particle velocity antinode of a specific cross-mode and another cylinder is positioned at its acoustic particle velocity node, i.e., a cylinder that should excite the resonance and another one that should not excite it, respectively; the excitation always takes over and the resonance occurs at a further elevated levels. It is also observed that the acoustic pressure levels in the cases of multiple cylinders are not resulting from a linear superposition of the excited level obtained from each individual cylinder which indicates that the removal of cylinders at certain locations may not be a viable technique to eliminate the acoustic resonance in the case of tube bundles.

On the Flow-Excited Acoustic Resonance of Isolated Cylinder(s) in Cross-Flow

2014 ◽  
Author(s):  
Nadim Arafa ◽  
Atef Mohany ◽  
Marwan Hassan
Keyword(s):  
Strouhal Number ◽  
Particle Velocity ◽  
Vortex Shedding ◽  
Acoustic Pressure ◽  
Cross Flow ◽  
Acoustic Resonance ◽  
Single Cylinder ◽  
Particle Velocities ◽  
Mode A ◽  
Flow Velocities

The flow-excited acoustic resonance of single and multiple cylinders in cross-flow is investigated experimentally. The effect of the cylinder(s) proximity to the acoustic particle velocity nodes of the first three acoustic cross-modes is presented. During the experiments, the acoustic cross-modes of the duct housing the cylinders are self-excited. For the case of a single cylinder, it is observed that although the cylinder’s location doesn’t significantly affect the vortex shedding process, it affects the mechanism of the flow-excited acoustic resonance and the levels of the generated acoustic pressure. When the cylinder is shifted away from the acoustic particle velocity anti-node of a specific acoustic cross-mode, a combination of cross-modes is excited with intensities that seem to be proportional to the ratio of the acoustic particle velocities of these modes at the cylinder’s location. For the case of two and three isolated cylinders positioned simultaneously side-by-side in the duct, it is observed that when the cylinders are positioned at different acoustic particle velocity anti-nodes of different cross-modes, the intensities of the excited acoustic resonance of these cross-modes are amplified compared to those with single cylinder. Nevertheless, when one cylinder is positioned at the acoustic particle velocity anti-node for a specific cross-mode and another cylinder is positioned at its acoustic particle velocity node, i.e. a cylinder that should excite the resonance and another one that should supress it, respectively; the excitation always takes over and the resonance occurs. Moreover, as the cylinder moves closer to the duct’s wall, the Strouhal number value decreases due to the interference between the wake of the cylinder and the wall. Therefore, the acoustic resonance for this case occurs at slightly higher flow velocities.

Sign in / Sign up

Export Citation Format

Share Document