University of Illinois Urbana-Champaign

Reynolds number scaling of flow in a Rushton turbine stirred tank: Part I--Mean flow, circular jet and tip vortex scaling

Balachandar, S.; Adrian, Ronald J.; Ha, M.Y.; Yoon, Hyun-Sik; Hill, David F.

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https://hdl.handle.net/2142/299

Description

Title
Reynolds number scaling of flow in a Rushton turbine stirred tank: Part I--Mean flow, circular jet and tip vortex scaling
Author(s)
  • Balachandar, S.
  • Adrian, Ronald J.
  • Ha, M.Y.
  • Yoon, Hyun-Sik
  • Hill, David F.
Issue Date
2003-08
Keyword(s)
Flow scaling
Abstract
We consider scaling of flow within a stirred tank with increasing Reynolds number. Experimental results obtained from two different tanks of diameter 152.5 and 292.1 mm, with a Rushton turbine operating at a wide range of rotational speeds stirring the fluid, are considered. The Reynolds number ranges from 4,000 to about 78,000. Phase-locked stereoscopic PIV measurements on three different vertical planes close to the impeller give phase-averaged mean flow on a cylindrical surface around the impeller. The scaling of q-averaged and plane-averaged radial, circumferential and axial mean velocity components is first explored. A theoretical model for the impeller-induced flow is used to extract the strength and size of the three dominant elements of the mean flow, namely the circumferential flow, the jet flow and the pairs of tip vortices. The scaling of these parameters with Reynolds number for the two different tanks is then obtained. The plane-averaged mean velocity scales with the blade tip velocity above a Reynolds number of about 15,000. However, parameters associated with the jet and tip vortices do not become Reynolds number independence until Re exceeds about 105. The results for the two tanks exhibit similar Reynolds number dependence, however, a perfect collapse is not observed, suggesting a sensitive dependence of the mean flow to the finer details of the impeller.
Publisher
Department of Theoretical and Applied Mechanics (UIUC)
Series/Report Name or Number
TAM Reports 1031
ISSN
0073-5264
Type of Resource
text
Language
en
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http://hdl.handle.net/2142/299

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Technical Reports - Theoretical and Applied Mechanics (TAM) PRIMARY
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.