Bubbles dynamics

A. A. Atchley and L. A. Crum, Acoustic cavitation and bubble dynamics, in Ultrasound, its Chemical, Physical and Biological Effect, K. S. Suslick, ed, VCH, New York (1988). 

B7. Barte, D. R., Bankoff, S. G., and Colahan, W. J., Summary of conference on bubble dynamics and boiling heat transfer held at the Jet Propulsion Laboratory, June 14th-15th, 1956, JPL Memo. No. 20-137, Calif. Inst. Tech., Pasadena. 

Although the absorption of a gas in a gas-liquid disperser is governed by basic mass-transfer phenomena, our knowledge of bubble dynamics and of the fluid dynamic conditions in the vessel are insufficient to permit the calculation of mass-transfer rates from first principles. One approach that is sometimes fruitful under conditions where our knowledge is insufficient to completely define the system is that of dimensional analysis. 

The bubble dynamics in a confined space, in particular in micro-channels, is quite different from that in infinity still fluid. In micro-channels the bubble evolution depends on a number of different factors such as existence of solid walls restricting bubble expansion in the transversal direction, a large gradient of the velocity and temperature field, etc. Some of these problems were discussed by Kandlikar (2002), Dhir (1998), and Peng et al. (1997). A detailed experimental study of bubble dynamics in a single and two parallel micro-channels was performed by Lee et al. (2004) and Li et al. (2004). 

Data by Lee et al. (2004) and Li et al. (2004) contain the results related to bubble dynamics in a single micro-channel and two parallel ones. The experimen-... 

The bubble dynamics under conditions corresponding to flow in two parallel trapezoidal micro-channels with hydraulic diameter 47.7 pm was studied by Li et al. (2004). The bubbles in two parallel micro-channels generally grow similarly to that in a single micro-channel. The authors reported on the presence of two-phase flow... 

Lee PC, Tseng FC, Pan C (2004) Bubble dynamics in microchannels. Part 1 single microchannel. Int J Heat Mass Transfer 47 5575-5589... 

Li HY, Tseng FC, Pan C (2004) Bubble dynamics in micro-channels. Part II two parallel microchannels. Int J Heat Mass Transfer 47 5591-5601 Li J, Cheng P (2004) Bubble cavitation in a micro-channel. Int J Heat Mass Transfer 47 2689-2698 Liu D, Lee PS, Gaiimella SV (2005) Prediction of the onset of nucleate boiling in microchannel flow. Int J Heat Mass Transfer 48 5134-5149... 

The multiplicity of phenomena characteristic of flow in heated micro-channels determined the content of the book. We consider a number of fundamental problems related to drag and heat transfer in flow of a pure liquid and a two-phase mixture in micro-channels, coolant boiling in restricted space, bubble dynamics, etc. Also considered are capillary flows with distinct interfaces developing under interaction of inertia, pressure, gravity, viscous and capillary forces. 

Wang, L.K., Bubble Dynamics of Adsorptive Bubble Separation Processes, 2007 National Engineers Week Seminar, Practicing Institute of Engineers, Albany, NY, February 2007. 

Krofta, M. and Wang, L.K., Bubble dynamics and air dispersion mechanisms of air flotation process system, Part B, The 44th Purdue Industrial Waste Conference Proceedings, Lewis Publishers, Chelsea, MI, 1990, pp. 505-515. 

The vapor pressure in the bubble is related to the liquid pressure at the bubble interface and the surface tension force by Eq. (2-3). Introducing this result into Eq. (2-28), the Rayleigh equation (Rayleigh, 1917) for isothermal bubble dynamics is obtained as... 

Note that high superheats, large liquid thermal conductivities, low pressures, and low bubble frequencies, all of which are more typical of liquid metals, tend to give bubble dynamics that approach the inertia-controlled case as the bubble growth rates are high. On the other hand, low superheats, low conductivities, high... 

Snyder, N. R., and D. K. Edwards, 1956, Post-Conference Comments Conference on Bubble Dynamics and Boiling Heat Transfer, Memo 20-137, p. 38, Jet Propulsion Lab., Pasadena, CA. (2)... 

Weninger KR, Camara CG, Putterman SJ (2001) Observation of bubble dynamics within luminescent cavitation clouds sonoluminescence at the nano-scale. Phys Rev E 63 016310... 

Prosperetti A, Lezzi A (1986) Bubble dynamics in a compressible liquid. Part I. First-order... 

Transient cavitation is generally due to gaseous or vapor filled cavities, which are believed to be produced at ultrasonic intensity greater than 10 W/cm2. Transient cavitation involves larger variation in the bubble sizes (maximum size reached by the cavity is few hundred times the initial size) over a time scale of few acoustic cycles. The life time of transient bubble is too small for any mass to flow by diffusion of the gas into or out of the bubble however evaporation and condensation of liquid within the cavity can take place freely. Hence, as there is no gas to act as cushion, the collapse is violent. Bubble dynamics analysis can be easily used to understand whether transient cavitation can occur for a particular set of operating conditions. A typical bubble dynamics profile for the case of transient cavitation has been given in Fig. 2.2. By assuming adiabatic collapse of bubble, the maximum temperature and pressure reached after the collapse can be estimated as follows [2]. 

The bubble formed in stable cavitation contains gas (and very small amount of vapor) at ultrasonic intensity in the range of 1-3 W/cm2. Stable cavitation involves formation of smaller bubbles with non linear oscillations over many acoustic cycles. The typical bubble dynamics profile for the case of stable cavitation has been shown in Fig. 2.3. The phenomenon of growth of bubbles in stable cavitation is due to rectified diffusion [4] where, influx of gas during the rarefaction is higher than the flux of gas going out during compression. The temperature and pressure generated in this type of cavitation is lower as compared to transient cavitation and can be estimated as ... 

Prediction of cavitational activity distribution based on theoretical analysis of the bubble dynamics equations can be used to identify the regions with maximum pressure fields in a large scale reactor and then may be small reactors can... 

If the power dissipated into the system is increased, although the collapse pressure, as predicted using bubble dynamics analysis [14], decreases with an increase in the intensity, the number of cavitation events also increases (increase is substantial as compared to the negative effect of decreasing collapse pressure) thereby increasing the overall cavitational activity and hence enhanced effects can be observed. Usually the increase in number of cavities generated seizes after a... 

Lauterbom W (1982) Cavitation bubble dynamics - new tools for an intricate problem. Appl Sci Res 38 165... 

---