Multidimensional heat, mass and flow phenomena in gas stirred reactors

Salcudean, M.; Lai, K. Y. M.; Guthrie, R. I. L.

doi:10.1002/cjce.5450630109

Cited by 32 publications

(5 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The previous solutions had not considered the effect of rotation on turbulence and the three-dimensional flow induced by the baffles except that a "drag term" was purposely added in the angular momentum equation in the two-dimensional solution by Harvey and Greaves (1982) to reduce the tangential velocity and increase the axial velocity, Accordingly, a turbulence model which can account for the threedimensional characteristics of this flow field was needed. The nonisotropic viscosity model developed in this study should be beneficial to studies of the turbulent flow field in other types of mixing vessels such as tubular reactors, Berker and Whitaker (1978); gas stirred reactors, Salcudean et al (1985); and jet-stirred reactors, Liu and Barkelew (1986).…”

mentioning

confidence: 99%

Three‐dimensional turbulent flow in agitated vessels with a nonisotropic viscosity turbulence model

Mulvahill

Pike

1990

Can J Chem Eng

View full text Add to dashboard Cite

Solutions of the time‐averaged equations of motion with a nonisotropic k‐e model were developed for the three‐dimensional turbulent flow field in turbine stirred tanks. These results were validated with the measurements of three velocity components with a hot wire anemometer and literature data. The nonisotropic turbulence model considered the rotation and curvature effect of the turbulence with a turbulent Richardson number term and accounted for the important three‐dimensional effects through the nonisotropy of the viscosity. Also, it was found that a frequently used isotropic k‐ϵ turbulence model did not describe this three‐dimensional turbulent flow field.

show abstract

mentioning

confidence: 99%

Three‐dimensional turbulent flow in agitated vessels with a nonisotropic viscosity turbulence model

Mulvahill

Pike

1990

Can J Chem Eng

View full text Add to dashboard Cite

show abstract

“…[12] and [13] represents the contribution due to phase-mass diffusion, and ⌫ k and ⌫ ε are diffusion coefficients expressed as t ⌫ ϭ ϩ [14] k l k t ⌫ ϭ ϩ [15] ε l ε in which k and ε are Schmidt numbers for k and ε, respectively, whose values have been established and widely applied. [25] The last terms of Eqs.…”

Section: Turbulence Modelmentioning

confidence: 99%

“…The early approaches [14,15] relied on a priori specification of the plume shape to simplify the problem. However, several studies [9,[16][17][18][19] have confirmed the significance of accurately representing the plume shape, especially when extrapolating from aqueous to metallic systems.…”

Section: Introductionmentioning

confidence: 99%

Modeling mean flow and turbulence characteristics in gas-agitated bath with top layer

Ilegbusi

Iguchi

Nakajima³

et al. 1998

Metall Mater Trans B

View full text Add to dashboard Cite

A numerical study is presented of the flow characteristics in a gas-agitated water bath in the presence of a top layer of dissimilar fluid. Two systems are considered, comprised separately of silicon and normal pentane as the top layer, to simulate slag cover in a real steelmaking process. The mathematical model involves solution of transport equations for the variables of each phase, with allowance for interphase transfer of momentum. Turbulence is assumed to be a property of the carrier (liquid) phase and represented through solution of additional transport equations for the turbulence kinetic energy, k, and its rate of dissipation, ε. The model also accounts for turbulence modulation by the bubbles through enhancement of the source terms in the equations for k and ε. The predicted mean and fluctuating velocities, stresses, and turbulence production are generally in the consensus of the experimental data. Both mean flow and turbulence characteristics are found to be suppressed in the water/silicon system of smaller density ratio, indicating enhanced re-entrainment of the top layer, than the water/normal pentane system.

show abstract

“…For the closure of momentum equations, concept of eddy viscosity is generally employed. Deb Roy et al (1978), Melville & Bray (1979), Sato et al (1981), Sahai & Guthrie (1982), Salcudean et al (1985) and Clark et al (1987) have proposed some empirical formulae for estimating effective turbulent viscosity in two-phase flows. However these equations prescribe a unique value of turbulent viscosity for the entire flow field and therefore fail to simulate effects of its variation within the system.…”

Section: Turbulene In Gas-liquid Flowsmentioning

confidence: 99%

Numerical simulation of dispersed gas-liquid flows

Ranade

1992

Sadhana

View full text Add to dashboard Cite

This paper reviews the available information on numerical simulation of dispersed gas-liquid flows. Emphasis is on informing the reader about various aspects of constructing simulation models rather than giving an exhaustive literature review. The information is organised in a way so as to provide answers to the following questions: how to formulate model equations? how to select suitable algorithms and numerical techniques to solve these model equations? how to translate these into workable computer codes? how to use such codes for simulating flows in industrial equipment? Though greater emphasis is given to dispersed gasliquid flows, the methodology can be applied to any multi-phase problem. Special features of multi-phase flow simulation over single-phase simulation are highlighted. A case of gas-liquid flow in a bubble column is presented as an illustration for the general methodology. The simulated mean flow field agrees reasonably with the experimental data. Properly validated CFD codes thus can serve as a useful tool for design engineers of multi-phase systems. Some of the common pitfalls in using simulation codes for design are also discussed. This review is expected to give an overall idea about the present state-of-art of two-phase simulation in industrial equipment.

show abstract

Multidimensional heat, mass and flow phenomena in gas stirred reactors

Cited by 32 publications

References 13 publications

Three‐dimensional turbulent flow in agitated vessels with a nonisotropic viscosity turbulence model

Three‐dimensional turbulent flow in agitated vessels with a nonisotropic viscosity turbulence model

Modeling mean flow and turbulence characteristics in gas-agitated bath with top layer

Numerical simulation of dispersed gas-liquid flows

Contact Info

Product

Resources

About