Corrigendum to ‘‘Use of angle resolved PIV to estimate local specific energy dissipation rates for up- and down-pumping pitched blade agitators in a stirred tank” [Chem. Eng. Sci. 64 (2009) 126–143]

2009 ◽  
Vol 64 (19) ◽  
pp. 4196 ◽  
Author(s):  
A. Gabriele ◽  
A.W. Nienow ◽  
M.J.H. Simmons
Keyword(s):  
Energy Dissipation ◽  
Specific Energy ◽  
Stirred Tank ◽  
Dissipation Rates

Micromixing Characteristics in an Aerated Stirred Tank with Half Elliptical Blade Disk Turbine

2014 ◽  
Vol 12 (1) ◽  
pp. 231-243
Author(s):  
Wanbo Li ◽  
Xingye Geng ◽  
Yuyun Bao ◽  
Zhengming Gao
Keyword(s):  
Energy Dissipation ◽  
Specific Energy ◽  
Dissipation Rate ◽  
Gas Flow ◽  
Liquid Surface ◽  
Energy Dissipation Rate ◽  
Reaction Scheme ◽  
Stirred Tank ◽  
Wall Region ◽  
Superficial Gas Velocity

Abstract The parallel-competing iodide-iodate reaction scheme was used to investigate the micromixing efficiency in an aerated stirred tank of 0.30 m diameter agitated by a half elliptical blade disk turbine. The mean specific energy dissipation rate Pm ranged from 0.5 to 2.2 W/kg, while the superficial gas velocity VS ranged from 0.015 to 0.047 m/s. Four sub-surface feed positions were considered. When the tank is fed just under the liquid surface or in the near-wall region, the micromixing efficiency can be enhanced by introducing gases with superficial gas velocities higher than 0.031 m/s. The effects of gas on the micromixing performance become complicated, while the tank is fed in the impeller discharging region. The increase of gas flow rate does not always have good effects on the micromixing performance. Moreover, the way to feed sulfuric acid can strongly affect the efficiency of the reaction scheme. For a single liquid phase, the micromixing time tm according to the incorporation model varies from 5 × 10−3 to 3 × 10−2 s. The dimensionless local specific energy dissipation rate Φ near the liquid surface is almost independent of Pm, while Φ in the impeller discharging area decreases with increasing Pm.

An Extension to the Incorporation Model of Micromixing and Its Use in Estimating Local Specific Energy Dissipation Rates

2008 ◽  
Vol 47 (10) ◽  
pp. 3460-3469 ◽  
Author(s):  
M. Assirelli ◽  
E. J. W. Wynn ◽  
W. Bujalski ◽  
A. Eaglesham ◽  
A. W. Nienow
Keyword(s):  
Energy Dissipation ◽  
Specific Energy ◽  
Dissipation Rates ◽  
Incorporation Model

Observations of Small-Scale Turbulence and Energy Dissipation Rates in the Cloudy Boundary Layer

2006 ◽  
Vol 63 (5) ◽  
pp. 1451-1466 ◽  
Author(s):  
Holger Siebert ◽  
Katrin Lehmann ◽  
Manfred Wendisch
Keyword(s):  
Boundary Layer ◽  
Energy Dissipation ◽  
Wind Velocity ◽  
Turbulence Theory ◽  
Horizontal Wind ◽  
Inertial Subrange ◽  
Intermittent Flow ◽  
Small Scale ◽  
Dissipation Rates ◽  
Wide Range

Abstract Tethered balloon–borne measurements with a resolution in the order of 10 cm in a cloudy boundary layer are presented. Two examples sampled under different conditions concerning the clouds' stage of life are discussed. The hypothesis tested here is that basic ideas of classical turbulence theory in boundary layer clouds are valid even to the decimeter scale. Power spectral densities S( f ) of air temperature, liquid water content, and wind velocity components show an inertial subrange behavior down to ≈20 cm. The mean energy dissipation rates are ∼10−3 m2 s−3 for both datasets. Estimated Taylor Reynolds numbers (Reλ) are ∼104, which indicates the turbulence is fully developed. The ratios between longitudinal and transversal S( f ) converge to a value close to 4/3, which is predicted by classical turbulence theory for local isotropic conditions. Probability density functions (PDFs) of wind velocity increments Δu are derived. The PDFs show significant deviations from a Gaussian distribution with longer tails typical for an intermittent flow. Local energy dissipation rates ɛτ are derived from subsequences with a duration of τ = 1 s. With a mean horizontal wind velocity of 8 m s−1, τ corresponds to a spatial scale of 8 m. The PDFs of ɛτ can be well approximated with a lognormal distribution that agrees with classical theory. Maximum values of ɛτ ≈ 10−1 m2 s−3 are found in the analyzed clouds. The consequences of this wide range of ɛτ values for particle–turbulence interaction are discussed.

scholarly journals Turbulence kinetic energy dissipation rates estimated from concurrent UAV and MU radar measurements

2018 ◽  
Vol 70 (1) ◽  
Author(s):  
Hubert Luce ◽  
Lakshmi Kantha ◽  
Hiroyuki Hashiguchi ◽  
Dale Lawrence ◽  
Abhiram Doddi
Keyword(s):  
Energy Dissipation ◽  
Kinetic Energy ◽  
Turbulence Kinetic Energy ◽  
Mu Radar ◽  
Dissipation Rates ◽  
Radar Measurements
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