Mean velocity field relative to a Rushton turbine blade

Journal Article · Sun Jan 01 04:00:00 EST 1995 · AIChE Journal (American Institute of Chemical Engineers); (United States)

DOI:https://doi.org/10.1002/aic.690410102· OSTI ID:6534344

Stoots, C M; Calabrese, R V ^[1]

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1. Univ. of Maryland, College Park, MD (United States). Dept. of Chemical Engineering

The development of accurate turbulent mixing and scaleup models for stirred-tank reactors has been limited by a lack of understanding of the three-dimensional turbulent velocity characteristics in such vessels. The 3-D flow field relative to a rotating Rushton turbine blade is acquired for fully turbulent tank conditions by synchronizing LDA measurements with the output of a shaft-mounted encoder. This makes it possible to capture the impeller stream velocity field, including the details of the vortices behind the blades. Mean velocity data at three impeller speeds show the extent of periodicity and the axes and structure of the vortices. Pumping capacities are determined and it is shown that the radial jet is a consequence of fluid entrainment into the vortices. Deformation rates based on gradients of mean velocity are calculated. Close to the blade they can exceed impeller rotational frequency by as much as two orders of magnitude. To a first approximation, the normalized mean flow field is independent of impeller speed.

• DOE Contract Number: AC07-76ID01570
• OSTI ID: 6534344
• Journal Information: AIChE Journal (American Institute of Chemical Engineers); (United States), Journal Name: AIChE Journal (American Institute of Chemical Engineers); (United States) Vol. 41:1; ISSN 0001-1541; ISSN AICEAC
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
ANEMOMETERS
CHEMICAL REACTORS
EQUIPMENT
FLOW MODELS
FLOW RATE
FLUID FLOW
LASER DOPPLER ANEMOMETERS
MATERIALS HANDLING EQUIPMENT
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MIXERS
THREE-DIMENSIONAL CALCULATIONS
TURBINE BLADES
TURBULENT FLOW