Growth of vapor bubbles in a highly superheated liquid

1981 ◽  
Vol 41 (5) ◽  
pp. 1233-1236
Author(s):  
P. A. Pavlov
1984 ◽  
Vol 106 (4) ◽  
pp. 486-490 ◽  
Author(s):  
G. L. Chahine ◽  
H. L. Liu

The problem of the growth of a spherical isolated bubble in a superheated liquid has been extensively studied. However, very little work has been done for the case of a cloud of bubbles. The collective behavior of the bubbles departs considerably from that of a single isolated bubble, due to the cumulative modification of the pressure field from all other bubbles. This paper presents a theoretical study on bubble interaction in a superheated liquid during the growth stage. The solution is sought in terms of matched asymptotic expansions in powers of ε, the ratio between rb0, a characteristic bubble radius and l0, the interbubble distance. Numerical results show a significant inhibition of the bubble growth rate due to the presence of interacting bubbles. In addition, the temperature at the bubble wall decreases at a slower rate. Consequently, the overall heat exchange during the bubble growth is reduced.


Author(s):  
Satish G. Kandlikar ◽  
Daniel A. Willistein ◽  
John Borrelli

The flow boiling process suffers from severe instabilities induced due to nucleation of vapor bubbles in a minichannel or a microchannel in a superheated liquid environment. In an effort to improve the flow boiling stability, several modifications are introduced and experiments are performed on 1054 × 197 μm microchannels with water as the working fluid. The cavity sizes and local liquid and wall conditions required at the onset of nucleation are analyzed. The effects of an inlet pressure restrictor and fabricated nucleation sites are evaluated as a means of stabilizing the flow boiling process and avoiding the backflow phenomena. The results are compared with the unrestricted flow configurations in smooth channels.


1968 ◽  
Vol 90 (1) ◽  
pp. 22-26 ◽  
Author(s):  
H. C. Hewitt ◽  
J. D. Parker

Experimental data on bubble growth in superheated liquid nitrogen, bubble collapse in subcooled liquid nitrogen, and bubble growth with decreasing liquid nitrogen pressure are compared to the theoretical solutions obtained for noncryogens. Vapor bubbles in liquid nitrogen were found to behave quite similarly to vapor bubbles in noncryogens. This paper provides experimental data in two areas where additional theoretical work is needed: Bubble collapse in subcooled liquid, and bubble growth with decreasing pressure.


1977 ◽  
Vol 12 (1) ◽  
pp. 44-51
Author(s):  
Yu. A. Kirichenko ◽  
A. V. Krytov ◽  
P. S. Chernyakov

2005 ◽  
Vol 128 (4) ◽  
pp. 389-396 ◽  
Author(s):  
Satish G. Kandlikar ◽  
Wai Keat Kuan ◽  
Daniel A. Willistein ◽  
John Borrelli

The flow boiling process suffers from severe instabilities induced due to nucleation of vapor bubbles in a superheated liquid environment in a minichannel or a microchannel. In an effort to improve the flow boiling stability, several modifications are introduced and experiments are performed on 1054×197μm parallel rectangular microchannels (hydraulic diameter of 332μm) with water as the working fluid. The cavity sizes and local liquid and wall conditions required at the onset of nucleation are analyzed. The effects of an inlet pressure restrictor and fabricated nucleation sites are evaluated as a means of stabilizing the flow boiling process and avoiding the backflow phenomenon. The results are compared with the unrestricted flow configurations in smooth channels.


Author(s):  
V.N. Moraru

The results of our work and a number of foreign studies indicate that the sharp increase in the heat transfer parameters (specific heat flux q and heat transfer coefficient _) at the boiling of nanofluids as compared to the base liquid (water) is due not only and not so much to the increase of the thermal conductivity of the nanofluids, but an intensification of the boiling process caused by a change in the state of the heating surface, its topological and chemical properties (porosity, roughness, wettability). The latter leads to a change in the internal characteristics of the boiling process and the average temperature of the superheated liquid layer. This circumstance makes it possible, on the basis of physical models of the liquids boiling and taking into account the parameters of the surface state (temperature, pressure) and properties of the coolant (the density and heat capacity of the liquid, the specific heat of vaporization and the heat capacity of the vapor), and also the internal characteristics of the boiling of liquids, to calculate the value of specific heat flux q. In this paper, the difference in the mechanisms of heat transfer during the boiling of single-phase (water) and two-phase nanofluids has been studied and a quantitative estimate of the q values for the boiling of the nanofluid is carried out based on the internal characteristics of the boiling process. The satisfactory agreement of the calculated values with the experimental data is a confirmation that the key factor in the growth of the heat transfer intensity at the boiling of nanofluids is indeed a change in the nature and microrelief of the heating surface. Bibl. 20, Fig. 9, Tab. 2.


2004 ◽  
Vol 35 (1-2) ◽  
pp. 59-66
Author(s):  
A. V. Reshetnikov ◽  
V. P. Skripov ◽  
V. P. Koverda ◽  
V. N. Skokov ◽  
N. A. Mazheiko ◽  
...  

Author(s):  
Mao Takeyama ◽  
Tomoaki Kunugi ◽  
Takehiko Yokomine ◽  
Zensaku Kawara

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