Anisotropic behavior of the Reynolds stress in gas and gas–solid flows in cyclones

Meier, Henry França; Mori, Milton

doi:10.1016/s0032-5910(98)00162-4

Cited by 46 publications

(32 citation statements)

References 8 publications

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“…In a Eulerian-Eulerian model, the Reynolds averaged equations have been used, as follows: where the subscript α represents the generic phase (solid or gas), ρ is the density of generic phase α, t represents the time and µ is the viscosity. Finally, u represents the velocity vector, defined by Reynolds averaged equation as (see Meier and Mori, 1999).…”

Section: Mathematical Modelingmentioning

confidence: 99%

“…For strongly swirling flows the standard k-ε turbulence model is know to have limitations (Meier and Mori., 1999). In order to obtain values for the Reynolds stress terms, a turbulence model, known as the Reynolds stress model (RSM), was used here.…”

Section: Mathematical Modelingmentioning

confidence: 99%

“…More details on this development can be found in Meier and Mori (1999), Bernardo (2005), Bernardo et al (2006) and ANSYS ® CFX ® -5.7 TM Users Guide.…”

Section: Reynolds Stress Modelmentioning

confidence: 99%

“…Cyclone dust collectors have been used in many industrial facilities to collect solid particles from gas-solid flows and to reduce air pollution originating in chimney smoke from chemical plant drier equipment (Ogawa, 1997). Currently, with new engineering applications of cyclones as dryers, reactors and particularly in the removal of high-cost catalysts from gases in petroleum refineries, industries require a greater understanding of turbulent gas flows, which could lead to rigorous procedures capable of accurately predicting efficiency, velocity and pressure fields (Meier and Mori, 1999).…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of cyclone geometry and its influence on performance parameters by computational fluid dynamics (CFD)

Martignoni

Bernardo

Quintani

2007

Braz. J. Chem. Eng.

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-Cyclone models have been used without relevant modifications for more than a century. Most of the attention has been focused on finding new methods to improve performance parameters. Recently, some studies were conducted to improve equipment performance by evaluating geometric effects on projects. In this work, the effect of cyclone geometry was studied through the creation of a symmetrical inlet and a volute scroll outlet section in an experimental cyclone and comparison to an ordinary single tangential inlet. The study was performed for gas-solid flow, based on an experimental study available in the literature, where a conventional cyclone model was used. Numerical experiments were performed by using CFX 5.7.1. The axial and tangential velocity components were evaluated using RSM and LES turbulence models. Results showed that these new designs can improve the cyclone performance parameters significantly and very interesting details were found on cyclone fluid dynamics properties using RSM and LES.

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Section: Mathematical Modelingmentioning

confidence: 99%

Section: Mathematical Modelingmentioning

confidence: 99%

“…More details on this development can be found in Meier and Mori (1999), Bernardo (2005), Bernardo et al (2006) and ANSYS ® CFX ® -5.7 TM Users Guide.…”

Section: Reynolds Stress Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Evaluation of cyclone geometry and its influence on performance parameters by computational fluid dynamics (CFD)

Martignoni

Bernardo

Quintani

2007

Braz. J. Chem. Eng.

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“…Optimization of geometry and optimal operation are the main aspects observed in the current developments and research. Dyakowski and Williams (1993), Cristea et al (1994), Meier and Mori (1999), and Meier et al (2002) developed numerical studies with experimental data on bench and industrial scales with geometries like Lapple and Stairmand for verification and validation in CFD 3-D, by using transient and turbulent models with the capability to represent the main phenomena of swirling flow in gas cyclones. The authors observed in all cases a poor representation of conventional turbulence closures using the isotropic behaviour of the Reynolds stress in the standard k-ε form.…”

Section: Introductionmentioning

confidence: 99%

A new role for reduction in pressure drop in cyclones using computational fluid dynamics techniques

Noriler

Vegini

Soares

et al. 2004

Braz. J. Chem. Eng.

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-In this work a new mechanical device to improve the gas flow in cyclones by pressure drop reduction is presented and discussed. This behavior occurs due to the effects of introducing swirling breakdown phenomenon at the inlet of the vortex finder tube. The device consists of a tube with two gas inlets in an appositive spiral flux that produces a sudden reduction in the tangential velocity peak responsible for practically 80 % of the pressure drop in cyclones. In turn, peak reduction causes a decrease in pressure drop by a breakdown of the swirling, and because of this the solid particles tend to move faster toward the wall , increasing collection efficiency. As a result of this phenomenon the overall performance of cyclones is improved. Numerical simulations with 3-D, transient, asymmetric and anisotropic turbulence closure by differential Reynolds stress for Lapple and Stairmand standard geometries of 0.3 m in diameter, show a reduction in pressure drop of 20 % and a shift of the tangential velocity peak toward the wall. All numerical experiments were carried out with a commercial CFD code showing numerical stability and good convergence rates with high-order interpolation schemes, SIMPLEC pressure-velocity coupling and other numerical features.

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Studies on strongly swirling flows in the full space of a volute cyclone separator

et al. 2005

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Anisotropic behavior of the Reynolds stress in gas and gas–solid flows in cyclones

Cited by 46 publications

References 8 publications

Evaluation of cyclone geometry and its influence on performance parameters by computational fluid dynamics (CFD)

Evaluation of cyclone geometry and its influence on performance parameters by computational fluid dynamics (CFD)

A new role for reduction in pressure drop in cyclones using computational fluid dynamics techniques

Studies on strongly swirling flows in the full space of a volute cyclone separator

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