scholarly journals Numerical Simulations on Gas-Liquid-Particle Flows in Three-Phase Slurry Reactors under gravity variation

2018 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Xinyu Zhang ◽  
Goodarz Ahmadi
Keyword(s):  
Numerical Simulations ◽  
Liquid Particle ◽  
Gravity Variation ◽  
Slurry Reactors ◽  
Particle Flows ◽  
Three Phase

CFD Evaluation of Bend Angle Effects on Sand Particle Erosion in Multiphase Flows

2020 ◽  
Author(s):  
A. Farokhipour ◽  
Z. Mansoori ◽  
M. Saffar-Avval ◽  
S. A. Shirazi ◽  
G. Ahmadi
Keyword(s):  
Erosion Rate ◽  
Industrial Applications ◽  
Bend Angle ◽  
Sand Particle ◽  
Liquid Particle ◽  
Particle Erosion ◽  
Particle Flows ◽  
Three Phase ◽  
Bend Angles ◽  
The Impact

Abstract In many industrial applications, gas-liquid-particle three-phase flows are observed. Predicting erosion damage in this type of flow is a challenging issue, and so many factors, such as the liquid film behavior have significant effects on the erosion rate. In the present study, the Eulerian-Lagrangian approach was implemented to study the process of sand particle erosion in elbows with different bend angles. For this purpose, gas and liquid phases under annular flow conditions were introduced at the pipe inlet, and the volume of fluid (VOF) method was employed to solve the governing equations. For evaluating the erosion rate, the Det Norske Veritas (DNV) model was applied. The predicted erosion results for the bend angles of 30°, 60° and 90° at different orientations were compared with those of the two-phase gas-particle flows. The simulation results indicated that for gas-liquid-particle flow, the behavior of film thickness in the bend plays a major role on the particle impact velocity and the corresponding erosion rates. By comparing the impact characteristics for gas and liquid superficial velocities of 40 and 0.4 m/s, respectively, in the 90° elbow, it was found that the impact velocities for gas-particle and gas-liquid-particle flows at the erosion hotspot are 38 and 14 m/s, respectively. In addition, among the studied geometries, the 30° elbow is the most erosion-resistant bend angle configuration among those studied for both two- and three-phase flows.

scholarly journals Numerical Study of Particle Interaction in Gas-Particle and Liquid-Particle Flows: Part I Analysis and Validation

2009 ◽  
Vol 1 (3) ◽  
pp. 217-244
Author(s):  
K. Mohanarangam ◽  
J. Y. Tu
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Numerical Study ◽  
Fluid Model ◽  
Particle Interaction ◽  
Sudden Expansion ◽  
Liquid Particle ◽  
Particle Flows ◽  
Dispersed Phases ◽  
Two Fluid Model

A detailed study into the turbulent behaviour of dilute particulate flow under the influence of two carrier phases namely gas and liquid has been carried out behind a sudden expansion geometry. The major endeavour of the study is to ascertain the response of the particles within the carrier (gas or liquid) phase. The main aim prompting the current study is the density difference between the carrier and the dispersed phases. While the ratio is quite high in terms of the dispersed phase for the gas-particle flows, the ratio is far more less in terms of the liquid-particle flows. Numerical simulations were carried out for both these classes of flows using an Eulerian two-fluid model with RNG based k- emodel as the turbulent closure. An additional kinetic energy equation to better represent the combined fluid-particle behaviour is also employed in the current set of simulations. In the first part of this two part series, experimental results of Fessler and Eaton (1995) for Gas-Particle (GP) flow and that of Founti and Klipfel (1998) for Liquid-Particle (LP) flow have been compared and analysed. This forms the basis of the current study which aims to look at the particulate behaviour under the influence of two carrier phases. Further numerical simulations were carried out to test whether the current numerical formulation can used to simulate these varied type of flows and the same were validated against the experimental data of both GP as well LP flow. Qualitative results have been obtained for both these classes of flows with their respective experimental data both at the mean as well as at the turbulence level for carrier as well as the dispersed phases.

scholarly journals AC Current Ripple in Three-Phase Four-Leg PWM Converters with Neutral Line Inductor

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1430
Author(s):  
Aleksandr Viatkin ◽  
Riccardo Mandrioli ◽  
Manel Hammami ◽  
Mattia Ricco ◽  
Gabriele Grandi
Keyword(s):  
Numerical Simulations ◽  
Pulse Width Modulation ◽  
Neutral Line ◽  
Experimental Tests ◽  
Performance Comparison ◽  
Design Parameters ◽  
Switching Frequency ◽  
Three Phase ◽  
Ac Current ◽  
Current Ripple

This paper presents a comprehensive study of peak-to-peak and root-mean-square (RMS) values of AC current ripples with balanced and unbalanced fundamental currents in a generic case of three-phase four-leg converters with uncoupled AC interface inductors present in all three phases and in neutral. The AC current ripple characteristics were determined for both phase and neutral currents, considering the sinusoidal pulse-width modulation (SPWM) method. The derived expressions are simple, effective, and ready for accurate AC current ripple calculations in three- or four-leg converters. This is particularly handy in the converter design process, since there is no need for heavy numerical simulations to determine an optimal set of design parameters, such as switching frequency and line inductances, based on the grid code or load restrictions in terms of AC current ripple. Particular attention has been paid to the performance comparison between the conventional three-phase three-leg converter and its four-leg counterpart, with distinct line inductance values in the neutral wire. In addition to that, a design example was performed to demonstrate the power of the derived equations. Numerical simulations and extensive experimental tests were thoroughly verified the analytical developments.

Three-phase slurry reactors

2016 ◽  
pp. 132-155 ◽  
Author(s):  
Vivek V. Buwa ◽  
Shantanu Roy ◽  
Vivek V. Ranade
Keyword(s):  
Slurry Reactors ◽  
Three Phase

scholarly journals Analysis of Input Voltage Switching Ripple in Three-Phase Four-Wire Split Capacitor PWM Inverters

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5076 ◽  
Author(s):  
Manel Hammami ◽  
Riccardo Mandrioli ◽  
Aleksandr Viatkin ◽  
Mattia Ricco ◽  
Gabriele Grandi
Keyword(s):  
Numerical Simulations ◽  
Comprehensive Evaluation ◽  
Experimental Tests ◽  
Input Voltage ◽  
Switching Voltage ◽  
Two Phase ◽  
Voltage Ripple ◽  
Battery Chargers ◽  
Three Phase ◽  
Split Capacitor

Three-phase, four-wire split capacitor inverters are currently employed in many applications, such as photovoltaic systems, battery chargers for electric vehicles, active power filters, and, in general, in all grid-tied applications that deal with possible grid voltage and/or current unbalances. This paper provides a comprehensive evaluation of the capacitor-switching voltage ripple and dc-link switching voltage ripple for the three-phase, four-wire, split capacitor inverters. Specifically, analytical formulations of the peak-to-peak and rms values of the voltage ripples are originally pointed out in this paper and determined in the case of balanced three-phase and unbalanced (two-phase and single-phase) output (ac) currents. The obtained results can help in designing the considered inverter and sizing of the dc-link capacitors. Reference is made to the sinusoidal PWM modulation and sinusoidal three-phase output currents with an almost unity power factor, representing a grid-connected application. Extensive numerical simulations have been carried out to thoroughly verify all the analytical developments presented in this paper. Furthermore, some experimental tests, having balanced output currents on the ac side, have been accomplished, validating numerical simulations and analytical developments.

Promotion of CO2 hydrogénation to hydrocarbons in three-phase catalytic (Fe-Cu-K-Al) slurry reactors

2003 ◽  
Vol 20 (5) ◽  
pp. 967-972 ◽  
Author(s):  
Jun-Sik Kim ◽  
Sang-Bong Lee ◽  
Min-Chul Kang ◽  
Kyu-Wan Lee ◽  
Myoung-Jae Choi ◽  
...  
Keyword(s):  
Co2 Hydrogenation ◽  
Slurry Reactors ◽  
Three Phase

Numerical Simulations of Reactive Diphasic Gas-Particle Flows

2007 ◽  
Author(s):  
Julien Nussbaum ◽  
Philippe Helluy ◽  
Jean-Marc Hérard ◽  
Alain Carrière
Keyword(s):  
Numerical Simulations ◽  
Particle Flows

Transient response of three-phase slurry reactors

1984 ◽  
Vol 39 (5) ◽  
pp. 893-901 ◽  
Author(s):  
Ravindra Datta ◽  
Robert G. Rinker
Keyword(s):  
Transient Response ◽  
Slurry Reactors ◽  
Three Phase
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