Evaluation of six k-ε turbulence model predictions of flow in a continuous casting billet-mold water model using laser doppler velocimetry measurements

Lan, Xin; Khodadadi, J. M.; Shen, Fangyang

doi:10.1007/s11663-997-0098-z

Cited by 24 publications

(18 citation statements)

References 13 publications

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“…The TurboSwirl was immersed into an overflow tank (Overflow tank 2), which is a transparent square plexiglass container that was used to eliminate the boundary curvature effect when using a camera to record the swirling flow and air-core vortex inside the TurboSwirl. 17) In order to investigate the swirling flow of the TurboSwirl, a steadystate condition should be gained inside the vertical runner, so the mold, which was supposed to be placed on top of the TurboSwirl, was not included in this water model experiment. Furthermore, if an excessive amount of water submerged the outlet of the TurboSwirl, the pressure and velocity profile were not compatible with the reality, so the pressure gauge of the outlet of the TurboSwirl was kept at a zero value.…”

Section: Water Modelmentioning

confidence: 99%

An Experimental and Numerical Study of Swirling Flow Generated by TurboSwirl in an Uphill Teeming Ingot Casting Process

2016

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Section: Water Modelmentioning

confidence: 99%

An Experimental and Numerical Study of Swirling Flow Generated by TurboSwirl in an Uphill Teeming Ingot Casting Process

2016

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“…31) It is critically important to validate models with experimental measurement. Several methods have been employed to measure the fluid flow velocity vectors in continuous casting mold system, including LDV (Laser Doppler Velocimetry) for mold 16,57) and for SEN nozzle 58,59) ), PIV (Particle Image Velocimetry), 19,25,60,61) hot wire anemometry 62) ; and propeller flow meters. [63][64][65] Figure 3 compares the instantaneous flow patterns predicted using physical and mathematical models for a typical double-roll flow pattern condition.…”

Section: Flow In the Moldmentioning

confidence: 99%

Mathematical Modeling of Iron and Steel Making Processes. Mathematical Modeling of Fluid Flow in Continuous Casting.

2001

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Fluid flow is very important to quality in the continuous casting of steel. With the high cost of empirical investigation and the increasing power of computer hardware and software, mathematical modeling is becoming an important tool to understand fluid flow phenomena. This paper reviews recent developments in modeling phenomena related to fluid flow in the continuous casting mold region, and the resulting implications for improving the process. These phenomena include turbulent flow in the nozzle and mold, the transport of bubbles and inclusion particles, multi-phase flow phenomena, the effect of electromagnetic forces, heat transfer, interfacial phenomena and interactions between the steel surface and the slag layers, the transport of solute elements and segregation. The work summarized in this paper can help to provide direction for further modeling investigation of the continuous casting mold, and to improve understanding of this important process.KEY WORDS: mathematical modeling; computational simulation; review; continuous casting; nozzles; molds; multiphase; turbulent; fluid flow; electromagnetic; coupled solidification; inclusion entrapment; segregation.steel. This paper will review recent developments in modeling each of the phenomena above, which are related to fluid flow in the continuous casting mold, and the resulting implications for improving the continuous casting process. Fluid Flow ModelingA typical three dimensional fluid flow model solves the continuity equation and Navier Stokes equations for incompressible Newtonian fluids, which are based on conserving mass (one equation) and momentum (three equations) at every point in a computational domain. 17,18) The solution of these equations, given elsewhere in this issue, 19) yields the pressure and velocity components at every point in the domain. At the high flow rates involved in this process, these models must incorporate turbulent fluid flow. Many different turbulence models have been employed by different researchers for fluid flow in continuous casting, such as effective viscosity models 20,21) (for the cylindrical mold and straight nozzle), one equation turbulence models (turbulent energy plus a given length-scale), 22) two-equation turbulence models such as the K-e Model, 19,23) LES (Large Eddy Simulation), [24][25][26][27][28] possibly with a SGS (sub-grid scale) model, 29,30) and DNS (Direction Numerical Simulation). 19)Among these models, direct numerical simulation is the simplest yet most computationally-demanding method. DNS uses a fine enough grid (mesh), to capture all of the turbulent eddies and their motion with time. To achieve more computationally-efficient results, turbulence is usually modeled on a courser grid using a time-averaged approximation, such as the popular K-e model, 23) which averages out the effect of turbulence using an increased effective viscosity field, m eff . This approach requires solving two additional partial differential equations for the transport of turbulent kinetic energy and its dissipation rate.19...

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“…[1][2][3][4][5][6][7][8][9][10] Fewer publications related with fluid flow in billet molds and particle image velocimetry (PIV) measurements are available, [11][12][13][14][15] probably because the conventional straight nozzles employed in this field work in a much more confined space, inducing what would be called standard flows with small variations of fluid flow patterns. However, the study presented here made clear that the complex nature of turbulent flows prevails even under the conditions of very stable flows, such as those expected in billet molds.…”

Section: Introductionmentioning

confidence: 99%

Influence of Straight Nozzles on Fluid Flow in Mold and Billet Quality

Torres-Alonso

Morales

Garcia-Hernandez

et al. 2008

Metall Mater Trans B

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Flux entrainment defects in a billet mold with two straight nozzles (outer radius of 60 mm, S60, and 73 mm, S73, and same interior radius of 36 mm) are studied using mathematical simulations and experimental techniques including particle image velocimetry (PIV), tracer injection, and water-oil modeling. Experimental findings indicated that using either of these nozzles at the deepest position of 135 mm (measured from the nozzle tip to the meniscus level) induces a flow near the meniscus, characterized by low turbulence yielding very stable water-oil interfaces. Simultaneously, owing to the mold radius, the entry jet induces a nonsymmetric flow downstream in the mold. At the shallow position of 90 mm, nozzle S73 induces a flow characterized by cyclic velocity spikes of low frequency and short duration close to the meniscus making the metal-flux interface highly instable. As the gap between the nozzle outer wall and the mold face is narrower and the nozzle position is shallower, the fluid close to the meniscus develops zones of high vorticity gradients leading to rotating flows, which are responsible for that instability. Water-oil experiments indicated that during the generation of this phenomenon, water flow entrains oil droplets in the side of the mold inner radius. Instability of metal-flux interface is then a consequence of the fluctuating nature of the recirculating flows in the mold, which induce upper rotating flows with large vorticity gradients. This mechanism explains actual flux entrainment defects in a billet caster.

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Evaluation of six k-ε turbulence model predictions of flow in a continuous casting billet-mold water model using laser doppler velocimetry measurements

Cited by 24 publications

References 13 publications

An Experimental and Numerical Study of Swirling Flow Generated by TurboSwirl in an Uphill Teeming Ingot Casting Process

An Experimental and Numerical Study of Swirling Flow Generated by TurboSwirl in an Uphill Teeming Ingot Casting Process

Mathematical Modeling of Iron and Steel Making Processes. Mathematical Modeling of Fluid Flow in Continuous Casting.

Influence of Straight Nozzles on Fluid Flow in Mold and Billet Quality

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