Bubble Formation Characteristic of Submerged Single-Hole Orifice in Inorganic Solution

2017 ◽  
Author(s):  
Jiming Wen ◽  
Haifeng Gu ◽  
Qiunan Sun ◽  
Zhongning Sun ◽  
Yanmin Zhou ◽  
...  
Keyword(s):  
Bubble Size ◽  
High Speed ◽  
Inorganic Salt ◽  
Bubble Column ◽  
Bubble Formation ◽  
Sodium Thiosulfate ◽  
Sodium Thiosulfate Solution ◽  
Obvious Effect ◽  
Filtration Method ◽  
Bubble Deformation

Bubble column is regarded as a kind of wet filtration method. The solution used in filter containment vented system is composed of a large amount of inorganic salt including sodium hydroxide and sodium thiosulfate. Solution with high inorganic salt concentration is more viscous and has stronger surface tension than distilled water. This property has significant effect on bubble size and bubble deformation during formation process. Besides bubble coalescent is suppressed with inorganic concentration increase. This phenomenon is found to possess influence on bubble formation regime when bubble formation regimes belong double, paring and injection regime. The existence of aerosol in solution is another factor that has obvious effect on bubble formation regime and the transition velocity between regimes. This paper apply high speed camera to study the influence rule of inorganic salt and aerosol concentration on bubble size during formation and formation regimes transition.

Computational and Experimental Investigation of Bubble Circulation Patterns Within a Column Photobioreactor

2011 ◽  
Author(s):  
S. M. Mortuza ◽  
Anil Kommareddy ◽  
Stephen P. Gent ◽  
Gary A. Anderson
Keyword(s):  
Flow Pattern ◽  
Bubble Size ◽  
High Speed ◽  
Bubble Column ◽  
Digital Camera ◽  
Design Parameters ◽  
Bubble Column Reactor ◽  
Vertical Column ◽  
Circulation Patterns ◽  
Multiple Bubbles

This research project investigates bubble and liquid circulation patterns in a vertical column photobioreactor (PBR) both experimentally as well as computationally using Computational Fluid Dynamics (CFD). Dispersed gas–liquid flow in the rectangular bubble column PBR are modeled using Eulerian–Lagrangian approach. A low Reynolds number k–ε CFD model is used to describe the flow pattern near the wall. Bubble size distribution measurements are carried out using a high-speed digital camera. A flat surface bubble column PBR is used to achieve sufficient light penetration into the system. Carbon dioxide, which is necessary for photosynthetic microalgae growth, is added to the sparged air. The results are validated with experimental data and from current literature. Design parameters, bubble flow pattern and internal hydrodynamics of a bubble column reactor were studied and the numerical simulations presented for the hydrodynamics in a bubble column PBR account for bubble phenomena that have not been sufficiently accounted for in previous research. Bubble size and shape affect the hydrodynamics as does bubble interaction with other bubbles (multiple bubbles in a flow versus single bubbles and wall effects on bubble(s) which are not symmetrical or bubbles not centered on the reactor cross-section). Understanding the bubble movement patterns will aid in predicting other design parameters like mass transfer (bubble to liquid and liquid to bubble), heat transfer (within the PBR and between the PBR and environment surrounding the PBR), and interaction forces inside the PBR.

Investigation of Bubble and Fluid Flow Patterns Within a Column Photobioreactor

2012 ◽  
Vol 9 (3) ◽  
Author(s):  
S. M. Mortuza ◽  
Stephen P. Gent ◽  
Anil Kommareddy ◽  
Gary A. Anderson
Keyword(s):  
Bubble Size ◽  
High Speed ◽  
Bubble Column ◽  
Digital Camera ◽  
Flow Patterns ◽  
Design Parameters ◽  
Bubble Column Reactor ◽  
Vertical Column ◽  
Multiple Bubbles ◽  
Gas Liquid Flow

This research study investigates bubble and liquid circulation patterns in a vertical column photobioreactor (PBR) both experimentally as well as computationally using computational fluid dynamics (CFD). Dispersed gas-liquid flow in the rectangular bubble column PBR are modeled using Eulerian-Lagrangian approach. A low Reynolds number k-epsilon CFD model is used to describe the flow pattern near the wall. A flat surface bubble column PBR is used to achieve sufficient light penetration into the system. Bubble size distribution measurements were completed using a high-speed digital camera. Operating parameters, bubble flow patterns, and internal hydrodynamics of a bubble column reactor were studied, and the numerical simulations presented for the hydrodynamics in a bubble column PBR account for bubble phenomena that have not been sufficiently accounted for in previous research. Bubble size and shape affect the hydrodynamics as does bubble interaction with other bubbles (multiple bubbles in a flow versus single bubbles and wall effects on bubble(s) that are not symmetrical or bubbles not centered on the reactor cross-section). Understanding the bubble movement patterns will aid in predicting other design parameters like mass transfer (bubble to liquid and liquid to bubble), heat transfer (within the PBR and between the PBR and environment surrounding the PBR), and interaction forces inside the PBR. The computational results are validated with experimental data and from current literature.

The Effect of Nozzle Shape and Configuration on Bubble Formation in a Liquid Cross Flow

2012 ◽  
Author(s):  
Mona Hassanzadeh Jobehdar ◽  
Aly H. Gadallah ◽  
Kamran Siddiqui ◽  
Wajid A. Chishty
Keyword(s):  
Liquid Flow ◽  
Bubble Size ◽  
High Speed ◽  
Waste Water Treatment ◽  
Bubble Formation ◽  
Cross Flow ◽  
Bubble Velocity ◽  
Two Dimensional ◽  
Flow Rates ◽  
Nozzle Shape

Gas injection into a liquid cross flow from a nozzle causes bubble formations which have potential applications in industry such as chemical plants, waste water treatment and bio- and nuclear-reactors. The purpose of this study is to experimentally investigate the effects of nozzle shape and configuration with respect to the liquid cross-flow direction, on the bubbly flow characteristics such as bubble formation, detached bubble size and frequency at different gas and liquid flow rates. The experiments were conducted in a Plexiglas two-dimensional rig using a high speed camera. High speed imaging and an image processing algorithm were used to track each individual bubble and to quantify the bubble growth as well as the detachment frequency and the bubble velocity. Back light shadowgraphy which utilizes a low intensity diffuse light source to illuminate the background was used to image bubbles. Nozzles were mounted in the test section which was designed such that the flow in this section has a two-dimensional profile. The results showed that the bubble size increases with an increase in GLR (gas to liquid flow rates ratio). Furthermore, the bubble formations and detached bubble size were strongly influenced by the nozzle shape and configuration.

Experimental investigation of bubble formation and motion mechanism near the moonpool

2021 ◽  
pp. 147509022110449
Author(s):  
Xiongliang Yao ◽  
Xianghong Huang ◽  
Zeyu Shi ◽  
Wei Xiao ◽  
Kainan Huang
Keyword(s):  
High Speed ◽  
Bubble Formation ◽  
Similarity Criteria ◽  
Dominant Factor ◽  
Acoustic Detection ◽  
Prototype Test ◽  
Tracer Particles ◽  
Research Ship ◽  
Image Velocimetry ◽  
Ventilation Method

When a research ship sails at a high speed, there is relative motion between the ship and fluid. The ship is slammed by the fluid. To reduce the direct impact of the fluid, sonar is installed in the moonpool, and acoustic detection equipment is installed along the research ship bottom behind the moonpool. However, during high-speed sailing, a large number of bubbles form in the moonpool. Some bubbles escape from the moonpool and flow backward along the bottom of the ship. When a large number of bubbles are around the sonar and acoustic detection equipment, the equipment malfunctions. However, there have been few studies on bubble formation in the moonpool with sonar and distribution along the ship bottom behind the moonpool. Therefore, a related model was developed and prototype tests were carried out in this study. The appropriate similarity criteria were selected and verified to ensure the reliability of the experiment. Considering the influences of speed, sonar, moonpool shape, and draft, the reason and mechanism of bubble formation in a sonar moonpool were studied. An artificial ventilation method was used to simulate a real navigation environment. Because the bubbles are in a bright state under laser irradiation, the bubbles can be used as tracer particles. A high-speed camera captured illuminated bubbles. The distribution mechanism of bubbles along the ship bottom behind the moonpool was investigated using particle image velocimetry under the influence of the moonpool shape and sailing speed. The model experimental results agreed well with those of the prototype test. The air sucked into the water was the dominant factor in bubble formation in the moonpool. The bubbles were distributed in a W shape under the ship bottom.

Using Wavelet Analysis to Distinguish Cavitation Acoustic Emissions From Blunt Impact Noise

2021 ◽  
Author(s):  
Christopher Eckersley ◽  
Joost Op 't Eynde ◽  
Mitchell Abrams ◽  
Cameron R. Bass
Keyword(s):  
Wavelet Transform ◽  
High Speed ◽  
Acoustic Noise ◽  
Bubble Formation ◽  
Acoustic Emissions ◽  
Wide Band ◽  
Water Tank ◽  
Impact Noise ◽  
Blunt Impact

Abstract Cavitation has been shown to have implications for head injury, but currently there is no solution for detecting the formation of cavitation through the skull during blunt impact. The goal of this communication is to confirm the wideband acoustic wavelet signature of cavitation collapse, and determine that this signature can be differentiated from the noise of a blunt impact. A controlled, laser induced cavitation study was conducted in an isolated water tank to confirm the wide band acoustic signature of cavitation collapse in the absence of a blunt impact. A clear acrylic surrogate head was impacted to induce blunt impact cavitation. The bubble formation was imaged using a high speed camera, and the collapse was synched up with the wavelet transform of the acoustic emission. Wideband acoustic response is seen in wavelet transform of positive laser induced cavitation tests, but absent in laser induced negative controls. Clear acrylic surrogate tests showed the wideband acoustic wavelet signature of collapse can be differentiated from acoustic noise generated by a blunt impact. Broadband acoustic signal can be used as a biomarker to detect the incidence of cavitation through the skull as it consists of frequencies that are low enough to potentially pass through the skull but high enough to differentiate from blunt impact noise. This lays the foundation for a vital tool to conduct CSF cavitation research in-vivo.

Bubble Formation From Porous Plates in Liquid Cross-Flow

2018 ◽  
Author(s):  
Thomas Shepard ◽  
Eric Ruud ◽  
Henry Kinane ◽  
Deify Law ◽  
Kohl Ordahl
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Bubble Diameter ◽  
Bubble Formation ◽  
Cross Flow ◽  
Rectangular Channels ◽  
Gas Liquid Flow ◽  
Liquid Flows ◽  
Processing Techniques ◽  
The Impact

Controlling bubble diameter and bubble size distribution is important for a variety of applications and active fields of research. In this study the formation of bubbles from porous plates in a liquid cross-flow is examined experimentally. By injecting air through porous plates of various media grades (0.2 to 100) into liquid flows in rectangular channels of varying aspect ratio (1–10) and gas/liquid flow rates the impact of the various factors is presented. Image processing techniques were used to measure bubble diameters and capture their formation from the porous plates. Mean bubble diameters ranged from 0.06–1.21 mm. The present work expands upon the work of [1] and further identifies the relative importance of wall shear stress, air injector pore size and gas to liquid mass flow ratio on bubble size and size distribution.

scholarly journals Acoustic Measurement in a Rectangular Bubble Column to Determine Bubble Size and Interfacial Area for Aqueous Solutions of Ethylene Glycol

2019 ◽  
Vol 8 (2) ◽  
pp. 994-998
Keyword(s):  
Ethylene Glycol ◽  
Bubble Size ◽  
Bubble Column ◽  
Bubble Diameter ◽  
Water System ◽  
Interfacial Area ◽  
Bed Height ◽  
Specific Interfacial Area ◽  
Bubble Sizes ◽  
Distributor Plate

Bubble sizes in bubble column affect the bubble induced mixing of phases, interfacial area and transfer processes. Acoustic technique is used to measure bubble size distribution in a rectangular bubble column of cross section 0.2m x 0.02m for air sparged into water and aqueous solutions of ethylene glycol. Five condenser mikes at intermediate distance of 0.05 m measured above the distributor plate were used to find out the variation of bubble size as the bubbles move up. Sauter-mean bubble diameter and specific interfacial area were estimated from bubble size distribution at several superficial air velocity, static bed height, distance above the distributor plate and ethylene glycol concentration. The BSD exhibited mono-modal distribution and indicated non-uniform homogeneous bubbling regime. Sauter-mean bubble diameter is independent of superficial gas velocity, static bed height and concentration of EG, although, the values were higher than that for air-water system. Sauter-mean bubble diameter decreases as the bubbles move up indicating bubble breakup to take place once the bubbles leave the sparger. The value of interfacial area increases as the static bed height decreases and distance above the distributor plate increases. For air-ethylene glycol solution the values of specific interfacial area are about 200% higher than that observed in case of air-water system. The acoustic technique may be used to measure local values of bubble sizes and specific interfacial area.

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