Study of Spatial Distribution of Kinetic Energy of Turbulence in a Cylindrical System with Turbine Impellers and Radial Baffles

The paper deals with the description and results of experimental investigation of spatial distribution of kinetic energy of turbulence in a cylindrical system with one or two standard turbine impellers on the same shaft and with radial bafflers at the vessel wall. The time-averaged specific kinetic energy of turbulence of agitated liquid is measured with a stirring-intensity-meter (SIM) consisting of mechanical-piezoelectric sensor and an auxiliary electronic device for processing the scanned fluctuation signal (the SIM calibration was carried out by means of a lasser-doppler anemometer). The measurements were performed in a model vessel of diameter D = 350 mm, in the range of values of Reynolds number for mixing ReM ∈ <1.2.103, 1.06.105> and relative size of impeller and vessel d/D = 0.286 in the single-phase and two-phase system (air was blown into the system through a sparger ring under the lower impeller). It follows from the measured and processed results that the spatial distribution of mean specific kinetic energy of turbulence in systems wit turbine impellers is considerably influenced by the amount of blown air: the mean specific kinetic energy of turbulence decreases with growing volumetric flow rate of air in the stream streaking from blades of rotating impeller, and, in the region outside this stream, it significantly increases.

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The Drag on Spheres and Cylinders in a Stream of Dust-Laden Air

Journal of Applied Mechanics ◽

10.1115/1.4012116 ◽

1959 ◽

Vol 26 (4) ◽

pp. 584-586

Author(s):

Thomas Gillespie ◽

A. W. Gunter

Keyword(s):

Particle Size ◽

Reynolds Number ◽

Kinetic Energy ◽

Drag Coefficient ◽

Flow Pattern ◽

Reynolds Numbers ◽

Dust Concentration ◽

Phase System ◽

Two Phase ◽

Coefficient Versus

Abstract A system has been developed for measuring the drag on small spheres and cylinders in a stream of dust-laden air. The drag was found to be proportional to the kinetic energy of the air plus the kinetic energy of the dust, and to be independent of particle size for particles having diameters in the range of 50 to 400μ. The well-known drag-coefficient versus Reynolds-number plots are the same for dust-free and dust-laden air provided the drag coefficient is calculated using the density of the two-phase system and the Reynolds numbers are calculated using the density of air alone. This suggests that the dust has little effect on the flow pattern. The results indicate that an instrument utilizing the drag principle to measure dust concentration could be developed.

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Continuum limits of particles interacting via diffusion

Abstract and Applied Analysis ◽

10.1155/s1085337504310080 ◽

2004 ◽

Vol 2004 (3) ◽

pp. 215-237 ◽

Cited By ~ 4

Author(s):

Nicholas D. Alikakos ◽

Giorgio Fusco ◽

Georgia Karali

Keyword(s):

Spatial Distribution ◽

Field Model ◽

Mean Field ◽

Critical Density ◽

Spherical Shape ◽

Interface Energy ◽

Three Dimensions ◽

Phase System ◽

Mean Field Model ◽

Two Phase

We consider a two-phase system mainly in three dimensions and we examine the coarsening of the spatial distribution, driven by the reduction of interface energy and limited by diffusion as described by the quasistatic Stefan free boundary problem. Under the appropriate scaling we pass rigorously to the limit by taking into account the motion of the centers and the deformation of the spherical shape. We distinguish between two different cases and we derive the classical mean-field model and another continuum limit corresponding to critical density which can be related to a continuity equation obtained recently by Niethammer andOtto. So, the theory of Lifshitz, Slyozov, and Wagner is improved by taking into account the geometry of the spatial distribution.

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The effect of vortex pairing on particle dispersion and kinetic energy transfer in a two-phase turbulent shear layer

International Journal of Multiphase Flow ◽

10.1016/s0301-9322(97)88431-5 ◽

1996 ◽

Vol 22 ◽

pp. 130

Author(s):

K Kiger

Keyword(s):

Energy Transfer ◽

Kinetic Energy ◽

Shear Layer ◽

Particle Dispersion ◽

Turbulent Shear ◽

Two Phase ◽

Turbulent Shear Layer ◽

Vortex Pairing ◽

Kinetic Energy Transfer

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THE CALCULATION OF THE EFFECTIVE BULK VISCOSITY OF TWO-PHASE SYSTEM CONSISTING OF LIQUID METAL OF THE WELD POOL AND SOLID PARTICLES REFRACTORY POWDER FILLER MATERIAL

10.21506/j.ponte.2018.2.6 ◽

2018 ◽

Vol 74 (2) ◽

Author(s):

Sergey Donskikh ◽

Semin V. N.

Keyword(s):

Liquid Metal ◽

Weld Pool ◽

Bulk Viscosity ◽

Solid Particles ◽

Filler Material ◽

Phase System ◽

Two Phase ◽

Refractory Powder ◽

Powder Filler

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On the Problem of “Two-Phase” Activated Sludge

Water Science & Technology ◽

10.2166/wst.1991.0185 ◽

1991 ◽

Vol 24 (7) ◽

pp. 59-64 ◽

Cited By ~ 1

Author(s):

R. W. Szetela

Keyword(s):

Activated Sludge ◽

Single Phase ◽

Phase System ◽

Two Phase ◽

Wastewater Treatment Process ◽

Sludge Stabilization ◽

Technological Advantage ◽

In Series ◽

State Models ◽

Activated Sludge Systems

Steady-state models are presented to describe the wastewater treatment process in two activated sludge systems. One of these makes use of a single complete-mix reactor; the other one involves two complete-mix reactors arranged in series. The in-series system is equivalent to what is known as the “two-phase” activated sludge, a concept which is now being launched throughout Poland in conjunction with the PROMLECZ technology under implementation. Analysis of the mathematical models has revealed the following: (1) treatment efficiency, excess sludge production, energy consumption, and the degree of sludge stabilization are identical in the two systems; (2) there exists a technological equivalence of “two-phase” sludge with “single-phase” sludge; (3) the “two-phase” system has no technological advantage over the “single-phase” system.

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Simulation of mechanically stirred two-phase liquid-gas flow

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19861001 ◽

1986 ◽

Vol 51 (5) ◽

pp. 1001-1015 ◽

Cited By ~ 2

Author(s):

Ivan Fořt ◽

Vladimír Rogalewicz ◽

Miroslav Richter

Keyword(s):

Spatial Distribution ◽

Velocity Field ◽

Gas Flow ◽

Liquid Velocity ◽

Model Parameters ◽

Two Phase ◽

Mean Velocity ◽

Rushton Turbine ◽

Low Viscosity ◽

Volumetric Gas Flow Rate

The study describes simulation of the motion of bubbles in gas, dispersed by a mechanical impeller in a turbulent low-viscosity liquid flow. The model employs the Monte Carlo method and it is based both on the knowledge of the mean velocity field of mixed liquid (mean motion) and of the spatial distribution of turbulence intensity ( fluctuating motion) in the investigated system - a cylindrical tank with radial baffles at the wall and with a standard (Rushton) turbine impeller in the vessel axis. Motion of the liquid is then superimposed with that of the bubbles in a still environment (ascending motion). The computation of the simulation includes determination of the spatial distribution of the gas holds-up (volumetric concentrations) in the agitated charge as well as of the total gas hold-up system depending on the impeller size and its frequency of revolutions, on the volumetric gas flow rate and the physical properties of gas and liquid. As model parameters, both liquid velocity field and normal gas bubbles distribution characteristics are considered, assuming that the bubbles in the system do not coalesce.

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Interphase distribution of 2-furylethylenes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19851642 ◽

1985 ◽

Vol 50 (8) ◽

pp. 1642-1647 ◽

Cited By ~ 2

Author(s):

Štefan Baláž ◽

Anton Kuchár ◽

Ernest Šturdík ◽

Michal Rosenberg ◽

Ladislav Štibrányi ◽

...

Keyword(s):

Partition Coefficient ◽

Partition Coefficients ◽

Transport Rate ◽

Phase System ◽

Two Phase ◽

Interphase Distribution ◽

Distribution Kinetics ◽

System 1 ◽

Kinetics Of

The distribution kinetics of 35 2-furylethylene derivatives in two-phase system 1-octanol-water was investigated. The transport rate parameters in direction water-1-octanol (l1) and backwards (l2) are partition coefficient P = l1/l2 dependent according to equations l1 = logP - log(βP + 1) + const., l2 = -log(βP + 1) + const., const. = -5.600, β = 0.261. Importance of this finding for assesment of distribution of compounds under investigation in biosystems and also the suitability of the presented method for determination of partition coefficients are discussed.

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