Experimental Bubble Growth Data

A classical set of experiments was performed by Dergarabedian (D2, D3) who irradiated water, carbon tetrachloride and other liquids, and photographed the asymptotic growth of minute bubbles originating within this uniformly superheated liquid. The superheat range was 2 to 10°C, and the pressure atmospheric, corresponding to Nj l. The initial and boundary conditions corresponded to the theory, so that the results are susceptible of 

Even when photographed at framing speeds in excess of 5000 frames/ 

The bubble is thus growing during most of its observable lifetime on the heating surface more slowly than predicted by the uniform superheat theory. 

Darby (Dl) has recently made a photographic study of boiling of water and Freon 113 from a single nucleation site induced by external infrared irradiation. Surprisingly enough, the bubble radius was found to vary closely as both before and after breakoff for all recorded runs. The data for both liquids were correlated by an expression of the form 

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M. Amon and C. D. Denson [33-34] attempted a theoretical and experimental examination of molding a thin plate from foamed thermoplastic. In the first part of the series [33] the authors examined bubble growth, and in the second [34] — used the obtained data to describe how the thin plate could be molded with reference to the complex situation characterized in our third note. Here, we are primarily interested in the model of bubble growth per se, and, of course, the appropriate simplification proposals [33]. Besides the conditions usual for such situations ideal gets, adherence to Henry s law, negligible mass of gas as compared to mass of liquid, absence of inertia, small Reynolds numbers, incompressibility of liquid, the authors postulated [33] several things that require discussion ... 

The method of Theofanous et al. (1969) should be the most accurate for predicting bubble growth rates in large volumes of liquid metals at uniform superheats, although there has been no experimental data against which to test it directly. 

On the other hand, if bubble growth is diffusion controlled, then the mass transfer coefficient may be meaningful. However, in this case, the surface area for mass transfer is the surface area of the bubbles entrained in the solution and this depends on the volume of liquid in the extraction zone and not on the surface area of the extraction zone. Clearly, attempts to correlate experimental data for the extraction of a volatile component from a polymeric solution containing entrained bubbles using mass transfer coefficients can be misleading or totally erroneous. 

Geochemical kinetics is stiU in its infancy, and much research is necessary. One task is the accumulation of kinetic data, such as experimental determination of reaction rate laws and rate coefficients for homogeneous reactions, diffusion coefficients of various components in various phases under various conditions (temperature, pressure, fluid compositions, and phase compositions), interface reaction rates as a function of supersaturation, crystal growth and dissolution rates, and bubble growth and dissolution rates. These data are critical to geological applications of kinetics. Data collection requires increasingly more sophisticated experimental apparatus and analytical instruments, and often new progresses arise from new instrumentation or methods. 

The functional form of Eq. (9-33) was determined by analyzing the significant parameters in bubble growth and dissipation. Experimental data for nucleate... 

Figure 10 Comparison of experimental data with numerical prediction for various gravity levels (a) bubble departure diameter and (b) bubble growth time.

Figure 13 Comparison of numerically predicted bubble growth with experimental data of Mukherjee and Dhir [18] for saturated water at earth normal gravity.

FIGURE 15.19 Bubble growth with the formation of an evaporation wave resulting in entrainment of small droplets into the bubble. 1, experimental data 2, Plesset and Zwick heat-transfer-controlled solution (Eq. 15.37) 3, Rayleigh solution with r(f) = 0 at t = 0.16 s 4, liquid pressure (from Barthau and Hahne [45], with permission). 

If experimental growth and collapse bubble radius data are employed, this equation can be numerically integrated to obtain Ap, the difference between the pressure at the bubble wall and in the surroundings, as a function of time (P3). If Ap can be assumed to be nearly constant, the first integral of this equation is readily obtained. 

Experimental results on bubble dynamics in solution of polymers are not numerous. Existing data characterize mainly the integral effects of polymeric additives on bulk phenomena associated with bubbles. A limited nttmber of works study the dynamics of an individual bubble. The observations of the bubble growth in water at a sudden pressure... 

Effect of Surface Tension at the liquid vapor interface (yig). The effect of yig on bubble growth profiles was studied by varying its value over a range of 1.923 mJ/m to 38.546 mJ/m. Note that the base case is yig = 18.7 mlW, which corresponds to the experimental case 6 in Table 1. It was shown that the effect of yig on the overall bubble growth profiles was minimal. As a consequence, the value of yig would not affect the fitting of the bubble growth simulations data to the empirical results, and hence the estimation of to set- The simulations carried out in this study are valid despite the uncertainty of the validity of surface tension data at the molecular level. 

The correlation of Werther (W9) gives nearly the same results as Eq. (2-5). Both correlations predict growth of bubble diameter and decrease of bubble frequency due to coalescence. However, experimental data in fluid beds have been excluded from the above correlations. 

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