Nonlinear Bubble Dynamics And The Effects On Propagation Through Near-Surface Bubble Layers

2004 ◽  
Author(s):  
Timothy G. Leighton
Keyword(s):  
Bubble Dynamics ◽  
Near Surface ◽  
Bubble Layers ◽  
Surface Bubble

Distribution of zooplankton inferred from hydroacoustic backscatter data in coastal waters off Ningaloo Reef, Western Australia

2002 ◽  
Vol 53 (6) ◽  
pp. 1005 ◽  
Author(s):  
Steven G. Wilson ◽  
Timothy Pauly ◽  
Mark G. Meekan
Keyword(s):  
Western Australia ◽  
Coastal Waters ◽  
Near Surface ◽  
Rhincodon Typus ◽  
Ningaloo Reef ◽  
The North ◽  
Whale Sharks ◽  
Bubble Layer ◽  
Surface Bubble

Hydroacoustic surveys were used to examine zooplankton distributions in coastal waters off Ningaloo Reef, Western Australia. Surveys were timed to coincide with the seasonal aggregation of whale sharks, Rhincodon typus, and other large zooplanktivores in these waters. The surveys examined scattering features of lagoon/shelf fronts, a series of cross-shelf transects and waters surrounding whale sharks swimming at the surface. These suggested that lagoon waters flow intrusively into shelf waters at reef passages in a layered exchange. Cross-shelf transects identified three vertical scattering layers: a surface bubble layer; a near-surface minimum layer; and a bottom maximum layer. Regions of intense mixing of lagoon and shelf waters were detected seaward and to the north of reef passages. Integrated acoustic mean volume backscatter of the bottom maximum layer increased with depth and distance offshore. Large subsurface aggregations of unidentified fauna were detected beneath whale sharks in the same area that manta rays and surface schools of euphausiids were also observed.

Effects of Wind-Induced Near-Surface Bubble Plumes on the Performance of Underwater Wireless Acoustic Sensor Networks

2016 ◽  
Vol 16 (11) ◽  
pp. 4092-4099 ◽  
Author(s):  
Amit Kumar Mandal ◽  
Sudip Misra ◽  
Tamoghna Ojha ◽  
Mihir Kumar Dash ◽  
Mohammad S. Obaidat
Keyword(s):  
Sensor Networks ◽  
Acoustic Sensor ◽  
Near Surface ◽  
Bubble Plumes ◽  
Acoustic Sensor Networks ◽  
Surface Bubble

FDTD modeling of low‐frequency sea surface reverberation in the presence of a near‐surface bubble layer

2000 ◽  
Vol 107 (5) ◽  
pp. 2922-2922
Author(s):  
Richard S. Keiffer ◽  
Robert A. Zingarelli ◽  
Jorge C. Novarini
Keyword(s):  
Low Frequency ◽  
Sea Surface ◽  
Near Surface ◽  
Bubble Layer ◽  
Surface Bubble

Boiling at subatmospheric pressures on hydrophobic surface: Bubble dynamics and heat transfer

2022 ◽  
Vol 173 ◽  
pp. 107423
Author(s):  
Anton Surtaev ◽  
Ali Koşar ◽  
Vladimir Serdyukov ◽  
Ivan Malakhov
Keyword(s):  
Heat Transfer ◽  
Bubble Dynamics ◽  
Hydrophobic Surface ◽  
Surface Bubble

Altering Bubble Dynamics via Vapor Extraction

2014 ◽  
Author(s):  
Randall G. Fox ◽  
Corey D. Juarez ◽  
Deborah V. Pence ◽  
James A. Liburdy
Keyword(s):  
High Speed ◽  
Bubble Dynamics ◽  
Heated Surface ◽  
Bubble Diameter ◽  
Nucleation Site ◽  
Vapor Extraction ◽  
High Speed Imaging ◽  
Conduction Model ◽  
Gap Height ◽  
Surface Bubble

Bubble dynamics in the presence of a porous confining surface through which vapor is extracted was experimentally investigated. Using a pulsed laser operating at 3500 pulses per second (pps), bubbles were generated at a single, 30 μm diameter nucleation site in a silicon disk. A time-averaged heat flux of 80 W/cm2 and a constant pressure differential of 35 kPa across a porous surface were maintained. The surface, a supported porous Teflon® membrane, has a nominal porosity of 55% and pore diameter of 0.45μm. Steady-state heating was achieved as determined from a one-dimensional conduction model yielding a dimensionless surface temperature fluctuations of less than 0.01%. Bubble diameter and frequency were determined using high-speed imaging for ten gap heights ranging between 0.52 mm and 3.99 mm, where the gap height is defined as the distance between the heated surface and the confining surface. Bubble dynamics of freely departing, coalescing, and rupturing bubbles are considered. Results are compared to diameters and frequencies achieved in unconfined (i.e. pool boiling) conditions. Isolated bubble dynamics depend on gap height and can be grouped into three ranges: greater than, equal to, and less than the bubble diameters for unconfined conditions, which for the present conditions is 1.53 mm. This paper is a work in progress.

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