Large eddy simulation of homogenization process in a pitched blade impeller mixed vessel

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21220%2F16%3A00304163" target="_blank" >RIV/68407700:21220/16:00304163 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Large eddy simulation of homogenization process in a pitched blade impeller mixed vessel

Popis výsledku v původním jazyce

This study deals with a large eddy simulation (LES) of the single-phase turbulent flow in a fully baffled mixed vessel stirred by a pitched six-blade impeller. The ANSYS FLUENT 15.7 commercial CFD program was employed. The LES turbulent model is used with the Dynamic Smagorinsky-Lilly model. The Werner-Wengle wall function is used to cope with the requirements of near the wall cell size of the LES model. The Sliding Mesh (SM) model was used for simulating the impeller movement. The surface of the liquid was assumed to be flat and the symmetry boundary condition was used at the place of surface. The Species Transport model was used to determine the time of homogenization and time course of tracer concentration was recorded during simulation. Experiments were carried out to compare with the simulation results. Two conductivity probes with different size of the measured volume were used. The probes were placed in the same locations as in the simulation. The mixing time was evaluated for different measurement points. The simulation results coincide very well with experiments. It was also checked by simulation that the chosen location of probes are best suited for the measurement of mixing time. Hydrodynamics in a mixed batch was also analyzed for examining of homogenization process. The radial profiles of the axial and radial component of the ensemble averaged mean velocity in the impeller discharge flow were obtained by simulation. These results were compared with experimental data obtained by previous LDA measurements of the radial profiles of the axial component of the ensemble averaged mean velocity in the impeller discharge flow. The volume flow rates and the flow rate criteria were calculated from these velocity profiles, and were compared with the flow rates determined from the horizontal vessel cross section from simulation. It was possible to determine the number of circulation of the batch required for its homogenization from the results.

Název v anglickém jazyce

Large eddy simulation of homogenization process in a pitched blade impeller mixed vessel

Popis výsledku anglicky

This study deals with a large eddy simulation (LES) of the single-phase turbulent flow in a fully baffled mixed vessel stirred by a pitched six-blade impeller. The ANSYS FLUENT 15.7 commercial CFD program was employed. The LES turbulent model is used with the Dynamic Smagorinsky-Lilly model. The Werner-Wengle wall function is used to cope with the requirements of near the wall cell size of the LES model. The Sliding Mesh (SM) model was used for simulating the impeller movement. The surface of the liquid was assumed to be flat and the symmetry boundary condition was used at the place of surface. The Species Transport model was used to determine the time of homogenization and time course of tracer concentration was recorded during simulation. Experiments were carried out to compare with the simulation results. Two conductivity probes with different size of the measured volume were used. The probes were placed in the same locations as in the simulation. The mixing time was evaluated for different measurement points. The simulation results coincide very well with experiments. It was also checked by simulation that the chosen location of probes are best suited for the measurement of mixing time. Hydrodynamics in a mixed batch was also analyzed for examining of homogenization process. The radial profiles of the axial and radial component of the ensemble averaged mean velocity in the impeller discharge flow were obtained by simulation. These results were compared with experimental data obtained by previous LDA measurements of the radial profiles of the axial component of the ensemble averaged mean velocity in the impeller discharge flow. The volume flow rates and the flow rate criteria were calculated from these velocity profiles, and were compared with the flow rates determined from the horizontal vessel cross section from simulation. It was possible to determine the number of circulation of the batch required for its homogenization from the results.

Druh

O - Ostatní výsledky

CEP obor

JP - Průmyslové procesy a zpracování

OECD FORD obor

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Projekt

<a href="/cs/project/GA14-18955S" target="_blank" >GA14-18955S: Experimentální a teoretická studie konvektivního přenosu tepla v rotujícím turbulentním impaktním proudu.</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů