Dynamics of an air bubble rising in constant and varying viscosity media

Sahu, Kirti Chandra and A R, Premlata (2018) Dynamics of an air bubble rising in constant and varying viscosity media. PhD thesis, Indian Institute of Technology, Hyderabad.

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Abstract

The dynamics of a gas bubble rising in a liquid is observed in many natural phenomena, and also in industrial applications. Due to its practical relevance, this has been studied from many centuries and it continues to be a problem of great interest even today. The main objectives of the thesis are to investigate some novel problems on bubble rising in viscosity varying systems. In several situations one could observed viscosity stratified media. Two of them are considered in this work. (a) When viscosity stratification is inherently present in the surrounding medium (say, viscosity of the outer fluid is increasing linearly with height). (b) When the outer fluid is a non-Newtonian fluid, wherein the surrounding fluid viscosity varies due to the shear caused by the motion of the bubble. Three-dimensional numerical simulations and experiments are performed to study these flows. The flow dynamics is governed by mass, momentum and energy conservation equations. A volume-of-fluid (VoF) approach is used to track the interface separating the fluids. The computational and experimental approaches used in this study are discussed in Chapter 2. The validations of the present numerical solver are also performed in the same chapter. In order to compare the bubble behaviour in a medium with varying viscosity with that observed in a constant viscosity medium (standard system), the dynamics of a rising bubble in a standard air-water system is also investigated.

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IITH Creators:
IITH CreatorsORCiD
Sahu, Kirti Chandrahttp://orcid.org/0000-0002-7357-1141
Item Type: Thesis (PhD)
Uncontrolled Keywords: Bubbles drops, Multiphase Flow
Subjects: Chemical Engineering
Divisions: Department of Chemical Engineering
Depositing User: Team Library
Date Deposited: 09 Apr 2018 06:47
Last Modified: 09 Apr 2018 06:47
URI: http://raiith.iith.ac.in/id/eprint/3852
Publisher URL:
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