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Bubble motion and mass transfer in non‐Newtonian fluids
Author(s) -
Barnett Stanley M.,
Humphrey Arthur E.,
Litt Mitchell
Publication year - 1966
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690120210
Subject(s) - bubble , mass transfer , reynolds number , non newtonian fluid , drag coefficient , newtonian fluid , drag , mechanics , mass transfer coefficient , rheology , added mass , spheres , chemistry , thermodynamics , physics , turbulence , quantum mechanics , astronomy , vibration
Instantaneous mass transfer coefficients were obtained for the absorption of carbon dioxide bubbles rising in an aqueous solution of sodium carboxymethylcellulose. The rheological character of the solutions was well described by the Ellis model. Mass transfer coefficients were high initially but trailed off rapidly with bubble age. Exceptions were found at specific diameters where the bubble shape went through a transition. At about 0.2 cm. a transition from ellipsoidal to a sphere shape occurred, which has also been observed in Newtonian fluids. At a larger diameter, however, the non‐Newtonian fluid showed a shape change from a spherical “cap” to a “top” shape and finally to an ellipsoid. A sudden increase of mass transfer coefficient accompanied each shape transition. Drag coefficient data were correlated successfully with a new Reynolds number. The Newtonian and power law portion of the Ellis model each contributed a component to the Reynolds number, which, when added together, correlated drag data for the bubbles as well as for glass spheres. Attempts to account for transition shape changes and bubble tailing in the non‐Newtonian fluid and their effects on bubble mass transfer are included.