CFD simulation of turbulent velocity field in the discharge streem from a standard Rushton turbine impeller

• Autorzy: Kysela B. , Fořt I. , Konfršt J.

Warianty tytułu

PL

Symulacja komputerowa (CFD) burzliwego pola prędkości w strumieniu wlotowym ze standardowej turbiny Rushtona

• Języki publikacji: EN

Abstrakty

EN

The velocity field around the standard Rushton turbine was investigated by the Computational Fluid Dynamics (CFD) calculations and compared with results obtained from the Laser Doppler Anemometry (LDA) measured in a pilot plant baffled cylindrical vessel. For calculations the Large Eddy Simulation (LES) approach was employed. The impeller motion was modeled using the Sliding Mesh technique (SM). The mean ensemble-averaged velocity profiles and root mean square values of fluctuations were compared in the radial discharge jet from the standard Rushton turbine under turbulent regime of flow of agitated liquid. There were found two subregions in the discharge stream and the values of the axial profiles of the radial component of the fluctuating velocity are rather same determined from the LES calculations and from the LDA measurements in the second one ZEF (zone of established flow) of the impeller discharge stream, but they differ in the first region ZFE (zone of flow establishment) in the impeller vicinity, although they exhibit the same shape. The impeller power number derived from calculations shows also good agreement with values introduced in literature with a significant influence of the thickness of the impeller disc.

PL

Pole prędkości wokół standardowej turbiny Rushtona przeanalizowano metodą CFD (Computer Fluid Dynamics) i porównano z wynikami uzyskanymi za pomocą laserowej anemometrii dopplerowskiej (LDA) w doświadczalnym zbiorniku cylindrycznym z przegrodami. W obliczeniach wykorzystano technikę LES (Large Eddy Simulation). Ruch mieszadła zamodelowano z zastosowaniem techniki SM (Sliding Mesh). Średnie ważone profile prędkości i średnie kwadratowe wartości fluktuacji porównano z promieniowym strumieniem cieczy wypływającej z turbiny Rushtona w warunkach burzliwego przepływu cieczy mieszanej. W strumieniu wypływającym z mieszadła wyodrębniono dwa podobszary, a przebiegi profili promieniowych składowych fluktuacji prędkości były zbliżone, zarówno otrzymane w wyniku obliczeń LES, jak i z pomiarów LDA w drugiej strefie przepływu ustabilizowanego w sąsiedztwie wirnika, chociaż wykazywały ten sam kształt. Liczba mocy mieszadła, otrzymana w wyniku obliczeń, wykazała dobrą zgodność z wartościami podawanymi w literaturze, przy znaczącym wpływie grubości tarczy mieszadła.

Słowa kluczowe

EN

Rushton turbine; mixing; CFD; LES; LDA/LDV; agitated vessel

PL

turbina Rushtona; mieszanie; CFD; LES; LDA/LDV; mieszalnik

• Wydawca: Wydawnictwo Politechniki Krakowskiej im. Tadeusza Kościuszki
• Czasopismo: Czasopismo Techniczne. Chemia
• Rocznik: 2014
• Tom: R. 111, z. 2-Ch
• Strony: 73--84
• Opis fizyczny: Bibliogr. 22 poz., il., wykr., wz.

Twórcy

autor

Kysela B.

• Institute of Hydrodynamics AS CR, Prague, Czech Republic

autor

Fořt I.

• Department of Process Engineering, Faculty of Mechanica l Engineering, Czech T echnical University in Prague, Czech Republic

autor

Konfršt J.

• Institute of Hydrodynamics AS CR, Prague, Czech Republic

Bibliografia

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Uwagi

EN

This research has been subsidized by the research project No. GA CR P101/12/2274 and RVO: 67985874.