Transient Hydrodynamics and Free Surface Capture of an Under-Baffled Stirred Tank During Stopping

• Published in: Chemical engineering research & design Vol. 85; no. 5; pp. 626 - 636
• Main Authors: Torré, J.P., Fletcher, D.F., Lasuye, T., Xuereb, C.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Rugby Elsevier B.V 2007; Institution of Chemical Engineers; Elsevier
• Subjects: agitator stopping; Applied sciences; CFD; Chemical and Process Engineering; Chemical engineering; Chemical Sciences; Engineering Sciences; Exact sciences and technology; free surface; Hydrodynamics of contact apparatus; Mixing; transient simulation; under-baffled vessel; CFD; free surface; agitator stopping; transient simulation; mixing; under-baffled vessel; Stirred vessel; Mixing; Turbulence; Two phase flow; Computational fluid dynamics; Prediction; Hydrodynamics; Agitator; Modeling; Steady state; Time dependence; Morphology; Under-baffled tank; Under-baffled vessel; Free surface; Transient simulation; Agitator stopping
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1205/cherd06174

The transient hydrodynamics and the free surface shape have been numerically predicted by CFD for an under-baffled agitated vessel during the stopping phase of the agitator, including the inertial period after the agitator has completely stopped. The simulations were carried out in a fully transient manner using a gas/liquid inhomogeneous two phase flow model coupled with a k– ɛ turbulence model. The time dependence of the system studied reveals that the history of the fluid evolution during the impeller slowing phase determines the instantaneous results, implying that the resulting hydrodynamics cannot be determined via a classical steady-state approach. The numerical prediction of the free surface shape during stopping is in agreement with experimental data.