Bubble Jet Flow Research Articles

Experimental study on the disturbance of microbubble liquid jets

The presence of microbubble significantly influences the rheological properties of a jet, thereby considerably increasing the complexity of the jet instability problem. However, the instability of microbubble jets has been rarely studied, and their breakup mechanism remains obscure. The present study was focused on conducting a comprehensive analysis of bubble jet flows. A high-precision experimental system was constructed to extract the time-series signals of each cross-sectional profile along the axial direction of a jet. Glycerol solutions with three different bubble volume fractions were prepared, and the standard deviation, spectral relationship, and nonlinear dynamical behavior (i.e., autocorrelation, phase space trajectory, Poincaré section, and Lyapunov exponent) were studied. The detailed development process of small surface disturbances in space was assessed, and the influence of variations in the bubble volume fraction on the nonlinear dynamics of the jet was examined. The results demonstrate that microbubbles can significantly change the energy transfer relationship between various sections of a jet and enhance the periodicity of the signal.

State sensing of bubble jet flow based on acoustic recognition and deep learning

This study covers the accidental generation of bubble jet flow caused by steam generator (SG) tubes damaging in sodium-cooled fast reactors (SFRs). The main objective of this study is to develop a novel state sensing method of bubble jet flow based on acoustic recognition and deep learning. Prior to the application of this method to actual SFRs, we utilize air and water as simulant fluids in order to perform the proof of concept. This study is divided into three phases. The first phase is the acquisition and analysis of pipe flow sound and bubble jet flow sound, each of which simulates the normal and anomaly sound from SG tubes in SFRs. The second phase is the preprocessing of acoustic signals and feature extraction. The third phase is the building of deep learning models and performance evaluation. As a result, every of our proposed models could distinguish between pipe flow sound and bubble jet sound with an accuracy of almost 100.00%, and the best model could classify pipe flow sound and three types of bubble jet flow sound with an accuracy of 99.76%. This result suggests that the acoustic recognition with deep learning has great potential to sense the state of bubble jet flow in actual SFRs.

State Sensing of Bubble Jet Flow Based on Acoustic Recognition and Deep Learning

State Sensing of Bubble Jet Flow Based on Acoustic Recognition and Deep Learning

Fluid dynamics model provides numerical framework for optimizing 3D bioprinting parameters

Addressing bubble dynamics and jet flow regimes leads to improved quality of laser-induced-forward-transfer bioprints.

Experimental investigation of bubble jet flow, sweeping and rotation on horizontal or inclined micro-wire during subcooled boiling

The generation and departure of bubbles are closely related to the boiling heat transfer efficiency. To investigate the bubble boiling characteristics on a heated micro-wire, platinum wires with diameter of 0.1 and 0.2 mm were used as the experimental material. The bubble dynamics over a horizontal heated wire and an inclined heated wire were investigated by a high-speed camera and an electronic microscope. The influences of heat flux and subcooled condition on the bubble departure diameter and the departure frequency were analyzed. The results showed that three kinds of bubble motion track were observed over the heated micro-wires under subcooled condition, including jet flow, sweeping, and rotation. The multi-jet flow phenomenon could be seen over the bubble on the heated 0.2 mm wire under the conditions of heat flux of 1.7 × 105 W m−2 and mainstream temperature of 36 °C. As the diameter increased, the bubbles grown on the lower side of the heated wire would gradually rotate over the wire. There were three phenomena observed on the 0.1 mm wire when two bubbles collided under conditions of 2.9 × 105 W m−2 heat flux and 34 °C mainstream temperature. For an inclined micro-wire with the inclined angle of 25°, the movement of the bubble would only move along the wire to the tip and eventually break away. When the mainstream temperature was 40 °C, the bubbles departure diameter and the frequency increased with the increase in heat flux. When the heat flux was 3.0 × 105 W m−2, the bubble departure diameter and frequency increased with the increase in temperature.

Micro vapor bubble jet flow for safe and high-rate fluorescence-activated cell sorting.

Safe, high-rate and cost-effective cell sorting is important for clinical cell isolation. However, commercial fluorescence-activated cell sorters (FACS) are expensive and prone to aerosol-induced sample contamination. Here we report a microfluidic cell sorter allowing high rate and fully enclosed cell sorting. The sorter chip consists of an array of micro heating hotspots. Pulsed resistive heating in the hotspots produces numerous micro vapor bubbles with short duration, which gives rise to a rapid jet flow for cell sorting. With this method, we demonstrated high sorting rate comparable to commercial FACS and the significant enrichment of rare cancer cells. This vapor bubble based cell sorting method can be a powerful tool for contamination-free and affordable clinical cell sorting such as circulating tumor cell isolation and cancer cell therapy.

Next-Generation Flow Sorting

Genetic Engineering & Biotechnology NewsVol. 33, No. 12 TutorialNext-Generation Flow SortingSilicon Microchip Capable of High-Frequency Fluidic Valving at Heart of TechnologyJim Linton and Shane W. OramJim LintonJim Linton Ph.D. (E-mail Address: jim@owlbiomedical.com), is chief business officer at Owl biomedical, and Shane W. Oram Ph.D. (E-mail Address: shaneo@miltenyi biotec.com), is global marketing manager—cell analysis at Miltenyi Biotec. Website: www.miltenyibiotec.com.Search for more papers by this author and Shane W. OramSearch for more papers by this authorPublished Online:11 Jun 2013https://doi.org/10.1089/gen.33.12.13AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View articleFiguresReferencesRelatedDetailsCited byFull-wafer in-situ fabrication and packaging of microfluidic flow cytometer with photo-patternable adhesive polymers21 November 2017 | Biomedical Microdevices, Vol. 20, No. 1Micro vapor bubble jet flow for safe and high-rate fluorescence-activated cell sorting1 January 2017 | Lab on a Chip, Vol. 17, No. 7 Volume 33Issue 12Jun 2013 Information© 2013 by GEN PublishingTo cite this article:Jim Linton and Shane W. Oram.Next-Generation Flow Sorting.Genetic Engineering & Biotechnology News.Jun 2013.30-31.http://doi.org/10.1089/gen.33.12.13Published in Volume: 33 Issue 12: June 11, 2013PDF download

Bubble jet flow interaction during pool boiling of subcooled water on horizontal thin wires

Both visual experiments and numerical analyses were conducted to investigate the interaction between bubble jet flows during pool boiling of subcooled water on horizontal thin wires. The bubble jet flows nearby attracted each other, and they can combine into one jet flow under strong interaction. As the adjacent bubble departs, the bubble jet flow would experience an unsteady evolution process with the jet flow interaction weakening. Since the unsymmetrical thermocapillary force at the bubble interface was induced by the adjacent bubble as a cold source, the bubble jet flow would trend to the adjacent bubble, and the mechanism based on thermocapillary force and cold source can explain the bubble jet flow interaction very well. The steady bubble jet flow interaction phenomena were further simulated by laminar model, and the calculated jet flow interaction phenomena were in a good agreement with the experimental results.

Recycling of Waste Concrete and Fixation of Carbon Dioxide by Micro Bubble Jet Flow

Recycling of Waste Concrete and Fixation of Carbon Dioxide by Micro Bubble Jet Flow

Flow Visualization and Image Measurement on a Bubble Jet Flow and Its Post-Processing by Using POD

Bubble jet flows are seen in a lot of industrial fields such as power plant, chemical plant and bio-reactor. PIV is very useful tool in order to investigate the bubble's behaviors and flow structures in liquid phase simultaneously. Because it is possible to measure two- or three-dimensional flow structures and the whole flow fields aren't disturbed by measurement instruments. Recently, Dynamic PIV system consisted of high-speed camera and high-repetition laser has been developed. It is possible to capture time-serial images with high temporal resolution. In this paper, a system combined dynamic PIV and IST (Infrared Shadow Technique) with single high-speed camera, a double-pulse laser for illumination of particles and a diode laser for illumination of bubbles is developed in order to capture particles and bubbles simultaneously. Some techniques about image pre-processing to separate particles and bubbles and velocity calculation by PIV/PTV are introduced. POD (Proper Orthogonal Decomposition) is furthermore applied to time-series liquid phase velocity vectors. It is revealed that the effect of spatio smooth filter is obtained by reconstructed velocity vectors in lower spatio mode by POD and it is changed from large vortex structures to small vortex structures as the spatio mode becomes higher.

J0502-1-4 PODによる気泡噴流の動解析([J0502-1]混相流の多次元ビジュアリゼーション～流動場の光・電磁場・超音波センシング～(1))

J0502-1-4 PODによる気泡噴流の動解析([J0502-1]混相流の多次元ビジュアリゼーション～流動場の光・電磁場・超音波センシング～(1))

Bubble jet flow formation during boiling of subcooled water on fine wires

Both visual technology and numerical simulation were employed to investigate bubble jet flow formation during boiling of subcooled water on ultrathin platinum wires. Experimental observations and measurements indicated that bubble jet flow formation could be typically divided into three stages: waiting, burst and stably developing stage. A transient numerical model was proposed to simulate the formation process accounting for the thermocapillary force existing at the bubble interface. The dynamical temperature variation in the liquid region, including the regions of the mushroom head and root stem, were numerically analyzed, showing a very good agreement with the experimental observations. The simulation very well explored the physical nature of the dynamical evolution of bubble jet flows and explained the experimental phenomena.

Bubble behavior during boiling of subcooled binary mixtures on very thin wires

AbstractExperimental investigations were conducted to explore the characteristics of subcooled nucleate boiling of binary mixtures composed of water and ethanol on very thin wires, and an emphasis was addressed to observe bubble movement and bubble jet flow. The experiments exhibited many different bubble jet flows, such as continuous, discontinuous, diverged, bifurcate jet flows, and small bubble spraying, corresponding to different vapor bubble sizes and bubble‐moving modes such as bubble initial momentum and bubble‐generating frequency. The bubble movement within the jet flow also was analyzed. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(2): 105–111, 2007; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/htj.20142

Flow and Aeration Characteristics of Micro Bubble Jet Flow

In this study, a new micro bubble generator, i.e. nozzle, with a very simple construction is proposed newly and the behavior, such as velocity distribution and spread, of micro bubble jet flow is made clear by PIV and LDA measurements of velocity distribution. The new nozzle uses a very high velocity water jet flow having a large velocity gradient near the nozzle exit. The shearing force shears the gas bubbles and makes considerable small bubbles or rather micro bubbles. The aeration characteristics of this micro bubble generator, i.e. nozzle, are also discussed.

B113 マイクロバブル気泡噴流の流動特性

B113 マイクロバブル気泡噴流の流動特性

気泡噴流の高速度PIV計測

気泡噴流の高速度PIV計測

Dynamics of Bubble Motion and Bubble Top Jet Flows From Moving Vapor Bubbles on Microwires

Rapid bubble sweeping along heated wires was observed during subcooled nucleate boiling experiments on very fine wires with jet flows emanating from the tops of the vapor bubbles for a variety of conditions. This paper presents experimental results with a numerical analysis of the physical mechanisms causing the experimentally observed bubble motion and jet flows. The results show that the moving bubble creates a nonuniform temperature distribution in the wire by cooling the wire as it moves along the wire with significant heat transfer in the wake behind the bubble. The results verify that the bubble motion is driven by the temperature difference from the front to the back of the bubble, which causes Marangoni flow. The Marangoni flow then thrusts the bubble forward along the wire with the calculated bubble velocities agreeing well with experimental measurements. In addition, the temperature difference from the bottom to the top of the bubble creates a vertical component to the Marangoni flow that results in the jet flows from the bubble tops. Comparisons with experimental observations suggest that the condensation heat transfer at the bubble interface is restricted by noncondensable gases that increase the surface temperature gradient and the resulting Marangoni flow. The numerical results also show that the heat transfer from the wire due to the Marangoni flow is significantly larger than the heat transfer due to the evaporation under the bubble.

Bubble sweeping and jet flows during nucleate boiling of subcooled liquids

An experimental investigation was conducted to investigate nucleate boiling on a very fine heating wire. By using zoom routine and CCD camera system, the dynamical process of nucleate boiling was visually observed. Sweeping bubbles and several modes of jet flows were described and discussed. For some cases, big bubbles, small bubbles, sweeping bubbles and jet flows coexisted in boiling system, and greatly enhanced heat transfer. These phenomena are quite different from usual observation of nucleate boiling. In this paper, the process of bubble sweeping phenomenon is described in detail and the effect induced by sweeping bubbles is argued. And also, several jet flows are illustrated and discussed, as well as the interaction between bubble sweeping and jet flows.

Application of fuzzy sets and neural network theory to the numerical pattern recognition of bubble flow and jet flow

The injection of gas into a liquid is associated with two characteristic flow regimes: bubble flow and jet flow. In metallurgy, these flow regimes are of interest with respect to refractory lifetime and mass transfer. The flow regimes were investigated in the systems water‐air and ethanol‐air by monitoring the bottom vibrations of a cold model. The vibrations were analyzed by numerical pattern recognition. The nominal Mach number of 1.1 is the criterion for the transition from bubble flow to jet flow. A numerical pattern recognition system which is able to distinguish between the flow regime below and above the nominal Mach number of 1.1, just by analyzing the vibration signal, is presented. This task can be accomplished in spite of the use of different liquids, nozzle diameters and liquid heights. As a classificator, both a fuzzy k nearest neighbour algorithm and a neural network were employed successfully. Fuzzy logic was found to be especially useful for describing the different flow regimes.