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Importance of using the correct impeller boundary conditions for CFD simulations of stirred tanks
Author(s) -
Fokema M. D.,
Kresta S. M.,
Wood P. E.
Publication year - 1994
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450720201
Subject(s) - impeller , turbulence , mechanics , dissipation , computational fluid dynamics , turbulence kinetic energy , slip factor , flow (mathematics) , turbine , boundary (topology) , boundary value problem , physics , engineering , mechanical engineering , mathematics , thermodynamics , mathematical analysis , quantum mechanics
Two experimentally determined sets of impeller boundary conditions were used to simulate the flow generated by a pitched blade turbine in a cylindrical baffled tank. Use of these two sets of boundary conditions in simulations with two different off bottom clearances led to the conclusion that the flow generated by a pitched blade impeller cannot be successfully predicted without considering the impeller location. Correct prediction of velocity fields in the tank required the correct specification of velocity boundary conditions. Successful prediction of the turbulent energy distribution required proper specification of the turbulence boundary conditions. There was almost no interaction between the velocity and turbulence fields. The turbulet kinetic energy dissipation rate was at a maximum close to the impeller in both geometries. Within this region the average dissipation rate was five and a half times greater that the average dissipation rate in the tank.