Flow characteristics analysis of a two-phase suspension between rotating porous cylinders with radial and axial flows

The flow characteristics problem of the two-phase suspension in the design of filters is presented, and the hydrodynamic stability is carried out to study the flow characteristics of a two-phase suspension between a rotating porous inner cylinder and a concentric, stationary, porous outer cylinder when radial flow and axial flow are present. Linear stability analysis results in an eigenvalue problem that is solved numerically by Wan?s method. The results reveal that the critical Taylor number for the onset of instability is altered by other parameters. For given correlation parameters, increasing the axial Reynolds number increases the critical Taylor number for transition very slightly, the critical Taylor number decreases as the axial Reynolds number becomes negative.

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Stability analysis of a two-phase suspension between rotating porous cylinder with the radial flow

Modern Physics Letters B ◽

10.1142/s0217984915500141 ◽

2015 ◽

Vol 29 (05) ◽

pp. 1550014

Author(s):

Feng-Hui Wang ◽

Yu-Chuan Zhu ◽

Zhan-Hong Wan ◽

Song He

Keyword(s):

Reynolds Number ◽

Stability Analysis ◽

Hydrodynamic Stability ◽

Stability Problem ◽

Radial Flow ◽

Wave Number ◽

Porous Cylinder ◽

Two Phase ◽

Stabilizing Effect ◽

The Stability

The hydrodynamic stability analysis of viscous flow between rotating porous cylinder has been researched for a long time by many researchers. But little works have been carried out about the linear stability analysis of the two-phase suspension. When the radial flow is present, the linear hydrodynamic stability analysis of suspension has been carried out between rotating porous cylinder. We know that the continuous and Stokes equations cannot only solve the stability problem of the continuous fluid phase, but also solving the stability problem of the discontinuous particle phase. The stability equations from an eigenvalue problem that was solved by a numerical technique based on Wan's method. The results reveal that the radial Reynolds number have a great effect on the critical Taylor number in the suspension. In this paper, we also researched on how the critical Taylor number changes as the radius ratio η, the axial wave number k, the particle concentration and the circumferential direction wave number happen to change with the radial Reynolds number increasing range from -5 to 5. Thus, our research discovered the radial inflow and outflow have a stabilizing effect on the two-phase suspension and the circumferential direction wave number also has a stabilizing effect.

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Entropy hemodynamics particle-fluid suspension model through eccentric catheterization for time-variant stenotic arterial wall: Catheter injection

International Journal of Geometric Methods in Modern Physics ◽

10.1142/s0219887819501640 ◽

2019 ◽

Vol 16 (11) ◽

pp. 1950164 ◽

Cited By ~ 8

Author(s):

Kh. S. Mekheimer ◽

A. Z. Zaher ◽

A. I. Abdellateef

Keyword(s):

Heat Transfer ◽

Shear Stress ◽

Temperature Distribution ◽

Wall Shear Stress ◽

Outer Cylinder ◽

Flow Characteristics ◽

Two Phase ◽

Eccentric Cylinder ◽

Wall Shear ◽

Suspension Model

Catheterization has an imperative rule in heat transfer investigations, which are frequently applied to analyze and deal with the heart transfer studies. Here, the entering of a catheter adjusts the flow of the blood and it affects the hemodynamic status in the artery region. In practical clinical cases, catheters cannot be precisely concentric with the artery. The impartial of this work is to investigate the behavior of a blood streaming characteristics, in the case of injecting the catheter eccentrically all the way through a stenotic overlapping artery. In this paper, we consider the heat transfer within the presence of blood corpuscle which has been characterized by a macroscopic two-phase model (i.e. a suspension of erythrocytes in plasma). The model here considers the blood fluid as a liquid fluid with adjourned particles in the gap bounded by the eccentric cylinder. The inside cylinder is identically rigid demonstrating the movable thin catheter and kept at constant temperature, where the outer cylinder is a taper cylinder demonstrating the artery that has overlapping stenosis and it is cooled and maintained at zero temperature. The coupled differential equations for both fluid (plasma) and particle (erythrocyte) phases have been solved. The expressions for the flow characteristics, namely, the flow rate, the impedance (resistance to flow), the wall shear stress and the temperature distribution, have been derived. The model is very useful in medicine, where the hemodynamic speed is higher for eccentric case than that of concentric one. Also, the temperature distribution and the entropy generation in the state of eccentric position are higher than in the case of the concentric position. A significant increase in the magnitude of the impedance and the wall shear stress occurs for an increase in the hematocrit, C for diseased blood.

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Heat Transfer Enhancement of Reactor Utilizing Taylor-Poiseuille Flow

Volume 8A: Heat Transfer and Thermal Engineering ◽

10.1115/imece2014-39854 ◽

2014 ◽

Author(s):

Li Ye ◽

Huajun Peng ◽

Bo Zhou ◽

Mo Yang ◽

Zheng Li ◽

...

Keyword(s):

Heat Transfer ◽

Reynolds Number ◽

Flow Regime ◽

Poiseuille Flow ◽

Axial Flow ◽

Local Heat Transfer ◽

Local Heat ◽

Taylor Number ◽

Transfer Coefficients ◽

Heat Transfer Coefficients

Numerical studies have been conducted to determine the heat transfer performances in a Taylor-Poiseuille flow regime. The flow is confined between two different heated, concentric cylinders. The inner cylinder is allowed to rotate while the outer one remains fixed, an axial flow is added. The influences of rotation Taylor number and axial Reynolds number on heat transfer coefficients are investigated. Results show that temperature in the flow regime presents a remarkable sinusoidal periodicity as the result of the axial arrangement of Taylor vortices, so does the local heat transfer coefficients. Heat transfer efficiency gets strengthened with increasing Taylor number, while damped with increasing Reynolds number. The accuracy of the simulation is validated by compared to the existing linear stability analysis.

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Taylor–Couette turbulence at radius ratio : scaling, flow structures and plumes

Journal of Fluid Mechanics ◽

10.1017/jfm.2016.352 ◽

2016 ◽

Vol 799 ◽

pp. 334-351 ◽

Cited By ~ 7

Author(s):

Roeland C. A. van der Veen ◽

Sander G. Huisman ◽

Sebastian Merbold ◽

Uwe Harlander ◽

Christoph Egbers ◽

...

Keyword(s):

Reynolds Number ◽

Outer Cylinder ◽

Azimuthal Velocity ◽

Velocity Profiles ◽

Radius Ratio ◽

Taylor Number ◽

Turbulent Regime ◽

Counter Rotation ◽

Taylor Couette ◽

Cylinder Rotation

Using high-resolution particle image velocimetry, we measure velocity profiles, the wind Reynolds number and characteristics of turbulent plumes in Taylor–Couette flow for a radius ratio of 0.5 and Taylor number of up to $6.2\times 10^{9}$. The extracted angular velocity profiles follow a log law more closely than the azimuthal velocity profiles due to the strong curvature of this ${\it\eta}=0.5$ set-up. The scaling of the wind Reynolds number with the Taylor number agrees with the theoretically predicted $3/7$ scaling for the classical turbulent regime, which is much more pronounced than for the well-explored ${\it\eta}=0.71$ case, for which the ultimate regime sets in at much lower Taylor number. By measuring at varying axial positions, roll structures are found for counter-rotation while no clear coherent structures are seen for pure inner cylinder rotation. In addition, turbulent plumes coming from the inner and outer cylinders are investigated. For pure inner cylinder rotation, the plumes in the radial velocity move away from the inner cylinder, while the plumes in the azimuthal velocity mainly move away from the outer cylinder. For counter-rotation, the mean radial flow in the roll structures strongly affects the direction and intensity of the turbulent plumes. Furthermore, it is experimentally confirmed that, in regions where plumes are emitted, boundary layer profiles with a logarithmic signature are created.

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A Two-Phase CFD Modeling Approach to Investigate the Flow Characteristics in Radial Flow Moving-Bed Reactors

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2014-0046 ◽

2014 ◽

Vol 12 (1) ◽

pp. 497-512 ◽

Cited By ~ 4

Author(s):

Fang-Zhi Xiao ◽

Zheng-Hong Luo

Keyword(s):

Radial Flow ◽

Solid Phase ◽

Flow Behavior ◽

Flow Characteristics ◽

Cfd Modeling ◽

Reactor Model ◽

Two Phase ◽

Moving Bed ◽

Porous Media Model ◽

Simulation Results

Abstract Based on a complete CFD Eulerian–Eulerian two-fluid approach, a comprehensive three-dimensional (3D) two-phase reactor model was suggested to describe the flow behavior in radial flow moving-bed reactors (RFMBRs). A porous media model was incorporated into the reactor model in order to describe the flow resistance provided by the porous walls of the center and annular pipes. Compared with these previous reactor models, the reactor model considers the solid-phase movement instead of immobilization, which benefits for predicting the formation of cavity practically. The simulation results are agreement with the published experimental data. By employing the verified model, the flow field parameters in the reactors such as pressure drop and flow velocity were obtained. Besides, the simulations were then carried out to investigate the effect of the bed voidage on the flow behavior and to understand the phenomenon of cavity in the RFMBRs. The simulation results showed that both the centripetal and the centrifugal flow configurations have the inhomogeneous flow distribution and the phenomenon of cavity. Furthermore, the inhomogeneous distribution increases with the increase of the bed voidage, whereas the phenomenon of cavity is more obvious with the increase of gas inlet velocity. As a whole, this work provided a realistic modeling and a useful approach for the understanding of RFMBRs.

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The stability of a viscous fluid between rotating cylinders with an axial flow

Journal of Fluid Mechanics ◽

10.1017/s0022112060001365 ◽

1960 ◽

Vol 9 (4) ◽

pp. 621-631 ◽

Cited By ~ 80

Author(s):

R. C. Diprima

Keyword(s):

Reynolds Number ◽

Viscous Fluid ◽

Axial Flow ◽

Taylor Number ◽

Small Reynolds Number ◽

Rotating Cylinders ◽

The Stability

The stability of a viscous fluid between two concentric rotating cylinders with an axial flow is investigated. It is assumed that the cylinders are rotating in the same direction and that the spacing between the cylinders is small. The critical Taylor number is computed for small Reynolds number associated with the axial flow. It is found that the critical Taylor number increases with increasing Reynolds number.

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INVESTIGATION OF STRATIFIED WAVY TWO-PHASE FLOW CHARACTERISTICS

Equipment ◽

10.1615/ihtc13.p12.130 ◽

2006 ◽

Author(s):

Marijus Seporaitis ◽

S. Gasiunas ◽

Raimondas Pabarcius

Keyword(s):

Two Phase Flow ◽

Flow Characteristics ◽

Phase Flow ◽

Two Phase

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Two-phase flow stability analysis using a level set approach

10.26678/abcm.cobem2017.cob17-0431 ◽

2017 ◽

Author(s):

Mamta Raju Jotkar ◽

Daniel Rodriguez ◽

Bruno Marins Soares

Keyword(s):

Stability Analysis ◽

Level Set ◽

Two Phase Flow ◽

Flow Stability ◽

Phase Flow ◽

Two Phase ◽

Level Set Approach

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Determination of specific interfacial areas in swirled two-phase flow

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19830842 ◽

1983 ◽

Vol 48 (3) ◽

pp. 842-853

Author(s):

Kurt Winkler ◽

František Kaštánek ◽

Jan Kratochvíl

Keyword(s):

Interfacial Area ◽

Liquid Volume ◽

Upward Flow ◽

Two Phase ◽

Flow Rates ◽

Mist Flow ◽

Interfacial Areas ◽

Correlation Parameters ◽

Flow Components

Specific gas-liquid interfacial area in flow tubes 70 mm in diameter of the length 725 and 1 450 mm resp. containing various swirl bodies were measured for concurrent upward flow in the ranges of average gas (air) velocities 11 to 35 ms-1 and liquid flow rates 13 to 80 m3 m-2 h-1 using the method of CO2 absorption into NaOH solutions. Two different flow regimes were observed: slug flow swirled annular-mist flow. In the latter case the determination was carried out separately for the film and spray flow components, respectively. The obtained specific areas range between 500 to 20 000 m3 m-2. Correlation parameters are energy dissipation criteria, related to the geometrical reactor volume and to the static liquid volume in the reactor.

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