Dynamics of a Spherical Bubble in Non-Newtonian Liquids

2021 ◽  
Vol 56 (4) ◽  
pp. 492-502
Author(s):  
A. N. Golubyatnikov ◽  
D. V. Ukrainskii
Author(s):  
P. J. Goodhew

Cavity nucleation and growth at grain and phase boundaries is of concern because it can lead to failure during creep and can lead to embrittlement as a result of radiation damage. Two major types of cavity are usually distinguished: The term bubble is applied to a cavity which contains gas at a pressure which is at least sufficient to support the surface tension (2g/r for a spherical bubble of radius r and surface energy g). The term void is generally applied to any cavity which contains less gas than this, but is not necessarily empty of gas. A void would therefore tend to shrink in the absence of any imposed driving force for growth, whereas a bubble would be stable or would tend to grow. It is widely considered that cavity nucleation always requires the presence of one or more gas atoms. However since it is extremely difficult to prepare experimental materials with a gas impurity concentration lower than their eventual cavity concentration there is little to be gained by debating this point.


1991 ◽  
Vol 1 (3) ◽  
pp. 239-252 ◽  
Author(s):  
Harry N. Buckner ◽  
Paul E. Sojka

2003 ◽  
Vol 13 (4) ◽  
pp. 395-412
Author(s):  
Maha Yamak ◽  
Shirley C. Tsai ◽  
Ken Law
Keyword(s):  

1981 ◽  
Vol 46 (9) ◽  
pp. 2032-2042 ◽  
Author(s):  
Pavel Seichter

A conductivity method has been used to assess the homogenization efficiency of screw impellers with draught tubes. The value of the criterion of homochronousness, i.e. the dimensionless time of homogenization, in the creeping flow regime of Newtonian liquids is dependent on the geometrical simplexes of the mixing system. In particular, on the ratio of diameters of the vessel and the impeller and on the ratio of the screw lead to the impeller diameter. Expression have been proposed to calculate the mixing times. Efficiency has been examined of individual configurations of screw impellers. The lowest energy requirements for homogenization have been found for the system with the ratio D/d = 2.


1981 ◽  
Vol 46 (9) ◽  
pp. 2021-2031 ◽  
Author(s):  
Pavel Seichter

Velocity profiles and pumping capacity have been determined using a thermistor anemometer in a vessel equipped with a screw impeller. In region of the creeping flow of a Newtonian liquid, i.e. for Re <15, the dimensionless pumping capacity is dependent on the geometrical arrangement of the mixing system. The efficiency was assessed of individual configuration from the value energy criterion expressing the dimensionless power requirements for recirculation of a highly viscous liquid in a vessel equipped with a screw impeller.


1986 ◽  
Vol 51 (10) ◽  
pp. 2127-2134 ◽  
Author(s):  
František Potůček ◽  
Jiří Stejskal

Absorption of oxygen into water and aqueous solutions of poly(acrylamides) was studied in an absorber with a wetted sphere. The effects of changes in the liquid flow rate and the polymer concentration on the liquid side mass transfer coefficient were examined. The results are expressed by correlations between dimensionless criteria modified for non-Newtonian liquids whose flow curve can be described by the Ostwald-de Waele model.


2002 ◽  
Vol 12 (2) ◽  
pp. 81-87 ◽  
Author(s):  
Christophe Baravian ◽  
Audrey Lalante ◽  
Alan Parker

Abstract The vane geometry with a large gap is used to determine the Newtonian, non-Newtonian and viscoelastic properties of complex fluids. We show that when this geometry is carefully characterized, it can be used for precise rheometry. A novel effective cylinder approximation is used to obtain the shear rate and shear stress factors. The effective radius is found to be close to the height of the triangle formed by joining the tips of adjacent blades. This result differs significantly from that of previous work. Flow visualization has been used to confirm that the stream lines bend towards the centre between the blades. These factors can be used to determine the flow curves of non-Newtonian liquids, using Krieger’s power law expansion. The standard procedure for using the vane to determine the yield stress is also carefully investigated and alternative procedures are suggested.


2015 ◽  
Vol 119 (27) ◽  
pp. 15339-15348 ◽  
Author(s):  
David A. Gregory ◽  
Andrew I. Campbell ◽  
Stephen J. Ebbens

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