Studying of the characteristics of a single bubble under subcooled liquid boiling

Abstract An experimental study of the characteristics of single (solitary) bubbles obtained by means of focused laser heating of the surface during the boiling of two subcooled liquids with significantly different properties: water and refrigerant R113 has been carried out. To obtain the most complete detailed information, the technique of synchronized high-speed video filming of the process in two mutually perpendicular planes with a frame rate of up to 150 kHz was used. It is shown that during the boiling of a subcooled liquid, the main mechanism of heat removal from the bubble dome into the surrounding liquid is an unsteady heat conductance. Differences in the behavior of solitary vapor bubbles in the case of boiling of two liquids (water and refrigerant R113) are shown.

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Thermocapillary rupture of a horizontal liquid layer on a silicon substrate

EPJ Web of Conferences ◽

10.1051/epjconf/201919600041 ◽

2019 ◽

Vol 196 ◽

pp. 00041

Author(s):

Dmitry Kochkin ◽

Valentin Belosludtsev ◽

Veronica Sulyaeva

Keyword(s):

Experimental Study ◽

Contact Line ◽

High Speed ◽

Video Camera ◽

Phase Contact ◽

High Speed Video ◽

High Speed Video Camera ◽

Three Phase ◽

Breakdown Phenomenon ◽

Dry Spot

This paper is an experimental study of thermocapillary breakdown phenomenon in a horizontal film of liquid placed on a silicon nonisothermal substrate. With the help of a high-speed video camera the speed of the three-phase contact line was measured during the growth of a dry spot.

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Microbubble Formation in Collapsing Process of a Single Vapor Bubble Injected in Subcooled Pool

ASME 2009 InterPACK Conference, Volume 2 ◽

10.1115/interpack2009-89160 ◽

2009 ◽

Cited By ~ 1

Author(s):

Ichiro Ueno ◽

Yasusuke Hattori

Keyword(s):

Heat Flux ◽

Vapor Bubble ◽

High Speed ◽

Narrow Range ◽

Heated Surface ◽

Lighting System ◽

Vapor Bubbles ◽

Bubble Behavior ◽

Subcooled Liquid ◽

Boiling Process

‘Microbubble emission boiling,’ known as MEB, is a phenomenon that emerges in a narrow range of subcooled condition with a higher heat flux than critical heat flux (CHF) accompanying with microbubble emission from the heated surface. The authors focus on the condensing process of vapor bubbles in order to comprehend the mechanism of the microbubble formation and emitting processes. In order to simplify a surely complex boiling process, the authors try to extract an interaction between the vapor bubble and the subcooled bulk in a boiling phenomenon, that is, growing and collapsing processes of a vapor bubble ejected to subcooled liquid bath. Vapor bubble is produced by vapor generate system, and ejected to a bulk of saturated distilled water at a designated degree of subcooling. The degree of subcooling is varied from 0 to 50 K. The growing/collapsing of vapor bubble behavior is detected by employing a high-speed camera at frame rates up to 50,000 fps with a back-lighting system. In the present study, the process of microbubble emission as well as the process of the irrupting vapor bubbles to the subcooled bulk is compared to that in a MEB on a thin wire.

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An Experimental Study of Microscopic Explosive Boiling Induced by Pulsed-Laser Irradiation

Heat Transfer, Volume 3 ◽

10.1115/imece2002-39065 ◽

2002 ◽

Author(s):

Xiulan Huai ◽

Zhaoyi Dong ◽

Dengying Liu ◽

G.-X. Wang

Keyword(s):

Experimental Study ◽

Heating Rate ◽

Laser Heating ◽

High Speed ◽

Quartz Substrate ◽

Pulsed Laser ◽

Bubble Nucleation ◽

Nucleation Temperature ◽

Heating Rates ◽

Explosive Boiling

Microscopic explosive boiling due to rapid heating has found many applications in modern technologies such as thermal ink jet printing, laser cleaning, and laser surgery. It is a nonequilibrium process involving an extremely high liquid superheating. This paper presents an experimental study of such an explosive vaporization process induced by firing a microsecond pulsed laser beam on a thin Pt film deposited on a quartz substrate. The temperature variation of the Pt film is measured by recording the electric resistance of the film during laser heating and subsequent cooling. A high-speed photographic technique is employed to visualize the bubble formation and the explosive evaporation process. Explosive boiling experiments have been carried out in either a pool of acetone liquid or a thin acetone film covering the Pt film. The heating rate achieved ranges from 8.0×106 K/s to 9.0×107 K/s. Violent explosive boiling was observed in the case of a liquid film and the vapor bubbles together with liquid droplets were expelled from the Pt film. While in the case of a liquid pool, only a large cluster of bubbles was formed on the Pt film during laser heating. A close examination of the temperature curves reveals a sudden reduction in the heating rate during laser heating, and an apparent bubble nucleation temperature can be defined. Experimental data show that this apparent bubble nucleation temperature is a strong function of the heating rate. It is close to the equilibrium boiling point at low heating rates while approaches the homogeneous nucleation temperature at high heating rates.

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Correlation Between Behaviors of the Vapor Bubbles and the Characteristics of the Heat Transfer Over the Heated Surface on MEB

Volume 2: Thermal Management; Data Centers and Energy Efficient Electronic Systems ◽

10.1115/ipack2013-73153 ◽

2013 ◽

Cited By ~ 2

Author(s):

Takahito Saiki ◽

Tomohiko Osawa ◽

Ichiro Ueno ◽

Chungpyo Hong

Keyword(s):

Heat Transfer ◽

Vapor Bubble ◽

High Speed ◽

Heated Surface ◽

High Heat ◽

Frame Rate ◽

High Heat Flux ◽

Heated Plate ◽

Thin Wire ◽

Vapor Bubbles

A series of experiments on subcooled pool boiling on a plate and on a thin wire are carried out. We focus on the condensation and collapse processes of vapor bubbles generated on the heated surface. We find the different patterns of the vapor bubble behaviors resulting in the emission of the microbubbles around the heated plate and the thin wire by employing high-speed observation with frame rate up to 150,000 frame per second (fps). From the experimental results, we provide a physical explanation on the correlation between the behavior of the vapor bubble at a high heat flux and the heat transfer characteristics. We propose this simple core-periphery model as a qualitative model for understanding the generation of the MEB.

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Determination of the geometry of laser-cutting fronts with high spatial and temporal resolution

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1135/1/012013 ◽

2021 ◽

Vol 1135 (1) ◽

pp. 012013

Author(s):

Michael Sawannia ◽

Peter Berger ◽

Rudolf Weber ◽

Thomas Graf

Keyword(s):

Laser Power ◽

High Speed ◽

Frame Rate ◽

Laser Fusion ◽

Normal Vector ◽

Local Surface ◽

Aisi 304 ◽

High Speed Video ◽

Laser Fusion Cutting

Abstract The melt flow velocity and the local surface angles of the cutting front during laser fusion cutting of 10 mm AISI 304 were determined for a laser power of 8 kW and a feed rate of 2 m/min. The cut front was recorded with a polarization goniometer, which uses the polarization of the process emission to determine the local surface angles, allowing to calculate the orientation of the normal vector of the surface. The records in this work were carried out with a frame rate of 75 kHz and a spatial resolution of about 30 µm. This allowed to identify big and small structures moving down the cutting front and to determine their velocities. The approximate velocity of the small structures was 9.1 m/s and for the big structures approx. 2.5 m/s. The information of a usual high-speed video was compared with the additionally obtained geometry information.

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Experimental study of bubble dynamics in highly wetting dielectric liquid pool boiling through high-speed video

2016 15th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm) ◽

10.1109/itherm.2016.7517571 ◽

2016 ◽

Cited By ~ 2

Author(s):

Wei Tong ◽

Chenlong Wu ◽

Kok Chuan Toh ◽

Fei Duan

Keyword(s):

Experimental Study ◽

High Speed ◽

Bubble Dynamics ◽

Pool Boiling ◽

Liquid Pool ◽

Dielectric Liquid ◽

High Speed Video

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Experimental study on EFO process of thermosonic wire bonding by using high-speed video record

2011 12th International Conference on Electronic Packaging Technology and High Density Packaging ◽

10.1109/icept.2011.6066786 ◽

2011 ◽

Cited By ~ 1

Author(s):

Xiang Kang ◽

Han Lei ◽

Wang Fu-liang ◽

Li Jun-hui

Keyword(s):

Experimental Study ◽

High Speed ◽

Wire Bonding ◽

High Speed Video ◽

Video Record ◽

Thermosonic Wire Bonding

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The Effects of Bubble Interface Contamination on Bubble Motion, Bubble-Induced Surrounding Liquid Motion and Mass Transfer

Volume 1A: Symposia, Part 2 ◽

10.1115/ajkfluids2015-30406 ◽

2015 ◽

Author(s):

Yuki Iburi ◽

Jie Huang ◽

Takayuki Saito

Keyword(s):

Mass Transfer ◽

Surface Tension ◽

High Speed ◽

Bubble Surface ◽

Dissolution Process ◽

Contaminated Water ◽

Equivalent Diameter ◽

Liquid Motion ◽

High Speed Video ◽

Surrounding Liquid

Mass transfer from a bubble to the surrounding liquid plays an important role in chemical engineering processes. To improve the efficiency and safety of the processes, a deep understanding of the mass transfer mechanism from bubbles to the surrounding liquid is essential. In the present study, we examined a CO2 single bubble of 2∼3 mm in equivalent diameter that ascended zigzag in purified water and contaminated water (500ppm 1-pentanol solution). We used a high speed video camera systems with high spatial and temporal resolution, for visualization of the bubble wake and bubble-induced surrounding liquid motion. The dissolution process of CO2 from the bubble to the surrounding liquid was visualized via LIF/HPTS (Laser Induced Fluorescence) method. HPTS, which is a fluorescent substance, was excited by Ar ion laser with a wavelength of 458 nm, then emitted with a wavelength of 513 nm. A pH level of CO2 solution decreased with increase in CO2 concentration; hence the emission intensity of HPTS was reduced. As a result, dark regions observed below the bubble rear accorded with the bubble wakes; from visualization of this bubble wakes through the high speed video cameras, dynamic CO2 dissolution process was obtained. In the purified water, the bubble shape was oblate ellipsoid, and horse-shoe-like vortices were formed in the rear of the bubble. On the other hand, in the contaminated water, the bubble was nearly spherical. Furthermore, behavior of the vortices changed. These different results in two conditions were caused by the decrease in the surface tension owing to the bubble surface contamination. While the bubble was rising, the non-uniform distribution of the surfactant on the bubble surface occurred. Hence, a gradient of the surface tension was formed on the bubble surface, furthermore, it caused the Marangoni convection. Meanwhile, in order to consider the relationship between dissolution process and the surrounding liquid motion, we measured the liquid phase velocities via PIV.

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Experimental Analysis of Altitude Relight Under Realistic Conditions Using Laser and High-Speed Video Techniques

Volume 2: Combustion, Fuels and Emissions, Parts A and B ◽

10.1115/gt2010-22625 ◽

2010 ◽

Cited By ~ 7

Author(s):

T. Mosbach ◽

R. Sadanandan ◽

W. Meier ◽

R. Eggels

Keyword(s):

Mass Flow ◽

High Speed ◽

Frame Rate ◽

Research Centre ◽

Oh Radicals ◽

Fuel Injector ◽

Flow Rates ◽

Flame Kernel ◽

High Speed Video ◽

Mass Flow Rates

The altitude relight performance of a lean fuel injector and combustor was investigated at the altitude relight test rig at the Rolls-Royce Strategic Research Centre (SRC) in Derby. The studies were performed for different mass flow rates of air and kerosene, a combustor temperature and pressure of 278 K and 0.5 bar, respectively. Good optical access to the combustion chamber enabled the application of optical and laser measuring techniques. High-speed video imaging in the UV and visible wavelength range at a frame rate of 3.5 kHz was used to visualize the temporal development of the flame kernel. The observed differences between the UV and visible flame emissions demonstrate the different origins of the luminosity, i.e. OH* chemiluminescence and soot radiation. Further, laser-induced fluorescence of kerosene and OH radicals was applied at a frame rate of 5 Hz to visualize the fuel distribution and regions of hot and reacting mixtures. For two exemplary flames with different mass flow rates and fuel-to-air ratios, the steady burning flames after successful ignition are characterized in this paper by the distributions of kerosene, OH*, OH and soot luminosity. An example of the flame kernel development for a successful ignition is given by an image sequence from a high-speed video recording of the chemiluminescence. The importance of the upstream movement of the flame kernel as a condition preceding successful flame stabilization is identified.

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