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Three Dimensional CFD Model of a Single Rising Bubble in Stagnant Liquids.
Crha, Jakub
Two-phase (gas-liquid) flows are fundamental to wide range of chemical industrial processes such as absorption or distillation. Gaseous\nphase is mostly represented by rising bubble swarms through the liquid bulk. Physicochemical properties of the liquid and gaseous phases\ntogether with the bubble diameter and shape largely affect the bubble rise velocity, which defines the residence time of the bubble in the liquidbulk.1. Bubble behaviour can be studied experimentally, theoretically or most recently - using CFD solvers. These solvers are designed\nto numerically solve Navier-Stokes equations.
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CFD Simulation of a Sub-millimetre Rising Bubble in a Stagnant Liquid.
Crha, Jakub ; Basařová, P. ; Kašpar, O.
Hydrodynamics of the multiphase apparatus is strongly affected by fluids used in the process. One of the main quantities, which determine the hydrodynamic behaviour is the rising velocity of gaseous bubbles. This velocity can be determined easily in small scale apparatuses, but it can be much more challenging in industrial-scale devices. For that reason, mathematical modeling is used. COMSOL Multiphysics, finite element CFD solver, was used to describe the behaviour of the single bubble rising in aqueous solutions of ethanol and n-propanol. Aqueous solutions of low-carbon alcohols are extensively used in many multiphase chemical processes such as distillation, flotation and in multiphase reactors. Bubble velocities and shapes obtained from the simulation were compared to experimental and theoretical values. Two initial diameters of bubbles were used – 0.6 and 0.8 mm. Terminal velocities and shapes deformations obtained from COMSOL of 0.6 mm bubble were in an agreement with theoretical and experimental values.
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