Microbubble Formation Dynamics Under High Heat Flux on Heaters with Different Aspect Ratios

Yang, I-Da; Tseng, Fan‐Gang; Chang, Chia‐Ming; Chieng, Ching-Chang

doi:10.1080/10893950500357921

Cited by 6 publications

(7 citation statements)

References 20 publications

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“…Additional research on microbubble dynamics [32] report changes in the slope of the bubble growth rate with no shrinkage in size before the maximum bubble size. These other works claim the bubble dynamics is related to its kinetic energy and reflected in the advancing contact angle [32]. Changes in contact angle may introduce different surface curvatures that along with surface tension may result in forces that change the bubble growing slope.…”

Section: Bubble Measurementmentioning

confidence: 94%

“…Researchers have found the bubble shrinking caused by the subcooling effect is also present in homogeneous boiling [31]. Additional research on microbubble dynamics [32] report changes in the slope of the bubble growth rate with no shrinkage in size before the maximum bubble size. These other works claim the bubble dynamics is related to its kinetic energy and reflected in the advancing contact angle [32].…”

Section: Bubble Measurementmentioning

confidence: 96%

See 1 more Smart Citation

Bubble growth characterization during fast boiling in an enclosed geometry

Escobar-Vargas

Fabris

González

et al. 2009

International Journal of Heat and Mass Transfer

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Section: Bubble Measurementmentioning

confidence: 94%

Section: Bubble Measurementmentioning

confidence: 96%

Bubble growth characterization during fast boiling in an enclosed geometry

Escobar-Vargas

Fabris

González

et al. 2009

International Journal of Heat and Mass Transfer

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“…In our previous work (Yang et al 2006), two possible explanations of this phenomenon have been raised, including: (1) implosion mechanism of cavitation whereby extremely high pressure are produced with compression wave, and (2) violent collapsing of a gas bubble in the liquid overshoots its equilibrium size and regrows many times. Figure 10 (DT = 0) shows the velocity fields during bubble growth/collapse processes at the cutting plane at Z = 16 lm for DT = 0 case.…”

Section: Power Supplymentioning

confidence: 98%

Efficient transfer and concentration of energy between explosive dual bubbles via time-delayed interactions

Chang

Yang

Lin

et al. 2009

Microfluid Nanofluid

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The dynamics of a high heat flux thermal bubble is constrained by the thermal energy carried on the bubble surface right after the bubble formation because of thermal isolation of vapor. This article proposes a way by assigning time delays between dual bubbles to transfer effectively energy from one bubble into the other, thus, breaks energy limitation that one single bubble can usually carry. Experiment result has demonstrated that the useful work as large as 40% can be transferred from one bubble into the other for the ignition time delay set between 2 and 3 ls in a dual bubble system. At the same time, the total extractable useful work in a dual bubble system is 20% higher than twice that of a single-bubble system with the same input heat energy. This phenomenon opens up a new way to transfer or concentrate energies from distributed energy sources with limit energy density into a much higher one for higher power application. Keywords Bubble dynamics Á Bubble interaction Á Energy transfer Á Energy efficiency Á Microbubble Á Microfluidics List of symbols S Cavity spacing, mm D b Average bubble departure diameter, mm D Separation distance between dual heaters, m D s Half of the maximum bubble size for single heater case, m MEMS Micro-electro-mechanical-systems DT Ignition time difference of two independently growing bubbles, ls I Electrical current, A r Resistance of platinum heater, X Area Heating surface area of the platinum heater, m 2 q 00 Heat flux, w/m 2 P b Bubble pressure, N/m 2 P ? Ambient pressure, N/m 2 R Bubble radius, m q l Density of liquid, kg/m 3 l l Viscosity of liquid, N s/m 2 r Surface tension of liquid, N/m V Bubble volume, m 3 t 0 Bubble initiating time t ?1/2max The time when bubble grows to half of the maximum bubble volume t maxThe time when volume of the bubble reaches the maximum bubble volume t -1/2max The time when bubble collapses to half of the maximum bubble volume A(t)Interfacial surface area, m 2 W(t)Useful mechanical work, J

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“…The detailed manufacturing process was described in reference [10]. For the study of shape factor effect, heaters of area 30 mm Â 30 mm, 30 mm Â 60 mm, and 20 mm Â 60 mm (i.e.…”

Section: Thermal Bubbles Generated On Microheatersmentioning

confidence: 99%

Droplet ejection and the induced flowfield by microthermal bubble during growth/collapse process

Yang¹,

Wu²,

Pan³

et al. 2006

Proceedings of the Institution of Mechanical Engineers, Part C:

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Numerical predictions on the entire process of droplet ejection by the growth/ collapse of an explosive microthermal bubble are achieved by first principle equations coupled with extended Rayleigh equations and Asai's pressure model. Supporting experiments such as the bubble size/shape image histories by high-speed camera and bubble-induced flowfield by microparticle image velocimetry are conducted for the impulsive and explosive process during the bubble growth/collapse. Excellent agreements between measurements and computations are obtained. Finally, the parameter studies on droplet ejections are conducted to seek the optimal designs for the ejection nozzle size, ink refilling chamber height, heat flux imposed, and the operating temperature.

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Microbubble Formation Dynamics Under High Heat Flux on Heaters with Different Aspect Ratios

Cited by 6 publications

References 20 publications

Bubble growth characterization during fast boiling in an enclosed geometry

Bubble growth characterization during fast boiling in an enclosed geometry

Efficient transfer and concentration of energy between explosive dual bubbles via time-delayed interactions

Droplet ejection and the induced flowfield by microthermal bubble during growth/collapse process

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