CFD Simulation of the Discharge Flow from Standard Rushton Impeller

Bohuš Kysela,Jiří Konfršt,Ivan Fořt,Zdeněk Chára

doi:10.1155/2014/706149

Abstract

The radial discharge jet from the standard Rushton turbine was investigated by the CFD calculations and compared with results from the Laser Doppler Anemometry (LDA) measurements. The Large Eddy Simulation (LES) approach was employed with Sliding Mesh (SM) model of the impeller motion. The obtained velocity profiles of the mean ensemble-averaged velocity and r.m.s. values of the fluctuating velocity were compared in several distances from the impeller blades. The calculated values of mean ensemble-averaged velocities are rather in good agreement with the measured ones as well as the derived power number from calculations. However, the values of fluctuating velocities are obviously lower from LES calculations than from LDA measurements.

Highlights

The flow inside the agitated vessel has a key role in the mixing processes
Where N = 24 is the number of compared points on the profile Wr∗ with index Laser Doppler Anemometry (LDA) means the value obtained from LDA measurements and with index CFD is the value interpolated from calculated profile from CFD
The flow in the discharge stream from the standard Rushton turbine was calculated by the Large Eddy Simulation approach

Summary

Introduction

The flow inside the agitated vessel has a key role in the mixing processes. The enormous progress of the computational equipment has allowed using more exacting turbulence models for solution of the flow in the agitated vessel. All calculations need some validation by the experimental results or by the analytical models. The radial impellers are most often used in experiments and calculations [16,17,18,19,20,21], namely, Rushton turbine, and there are analytical models, where the impeller discharge stream is modeled as a turbulent jet [1, 2, 16, 19, 20]

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Results

Conclusion