Effect of electromagnetic ruler braking (embr) on transient turbulent flow in continuous slab casting using large eddy simulations

R. Chaudhary, B. G. Thomas, Surya Pratap Vanka

Research output: Contribution to journalArticle

Abstract

Static electromagnetic braking (EMBr) fields affect greatly the turbulent flow pattern in steel continuous casting, which leads to potential benefits such as decreasing flow instability, surface defects, and inclusion entrapment if applied correctly. To gain a fundamental understanding of how EMBr affects transient turbulent flow, the current work applies large eddy simulations (LES) to investigate the effect of three EMBr ruler brake configurations on transient turbulent flow through the bifurcated nozzle and mold of a liquid-metal GaInSn model of a typical steel slab-casting process, but with deep nozzle submergence and insulated walls with no solidifying shell. The LES calculations are performed using an in-house graphic-processing-unit-based computational-fluid- dynamics code (LES-CU-FLOW) on a mesh of ~7 million brick cells. The LES model is validated first via ultrasonic velocimetry measurements in this system. It is then applied to quantify the mean and instantaneous flow structures, Reynolds stresses, turbulent kinetic energy and its budgets, and proper orthogonal modes of four cases. Positioning the strongest part of the ruler magnetic field over the nozzle bottom suppresses turbulence in this region, thus reducing nozzle well swirl and its alternation. This process leads to strong and focused jets entering the mold cavity making large-scale and low-frequency (<0.02 Hz) flow variations in the mold with detrimental surface velocity variations. Lowering the ruler below nozzle deflects the jets upward, leading to faster surface velocities than the other cases. The double-ruler and no-EMBr cases have the most stable flow. The magnetic field generates largescale vortical structures tending toward two-dimensional (2-D) turbulence. To avoid detrimental large-scale, low-frequency flow variations, it is recommended to avoid strong magnetic fields across the nozzle well and port regions

Original languageEnglish (US)
Pages (from-to)532-553
Number of pages22
JournalMetallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
Volume43
Issue number3
DOIs
StatePublished - Jun 1 2012

Fingerprint

braking
Large eddy simulation
large eddy simulation
Braking
turbulent flow
nozzles
Turbulent flow
Nozzles
Casting
slabs
electromagnetism
Steel
Magnetic fields
Turbulence
turbulence
magnetic fields
steels
low frequencies
energy budgets
brakes

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys
  • Materials Chemistry

Cite this

@article{1eee1fc7d7d94fdfa0ac9d555b8894c3,
title = "Effect of electromagnetic ruler braking (embr) on transient turbulent flow in continuous slab casting using large eddy simulations",
abstract = "Static electromagnetic braking (EMBr) fields affect greatly the turbulent flow pattern in steel continuous casting, which leads to potential benefits such as decreasing flow instability, surface defects, and inclusion entrapment if applied correctly. To gain a fundamental understanding of how EMBr affects transient turbulent flow, the current work applies large eddy simulations (LES) to investigate the effect of three EMBr ruler brake configurations on transient turbulent flow through the bifurcated nozzle and mold of a liquid-metal GaInSn model of a typical steel slab-casting process, but with deep nozzle submergence and insulated walls with no solidifying shell. The LES calculations are performed using an in-house graphic-processing-unit-based computational-fluid- dynamics code (LES-CU-FLOW) on a mesh of ~7 million brick cells. The LES model is validated first via ultrasonic velocimetry measurements in this system. It is then applied to quantify the mean and instantaneous flow structures, Reynolds stresses, turbulent kinetic energy and its budgets, and proper orthogonal modes of four cases. Positioning the strongest part of the ruler magnetic field over the nozzle bottom suppresses turbulence in this region, thus reducing nozzle well swirl and its alternation. This process leads to strong and focused jets entering the mold cavity making large-scale and low-frequency (<0.02 Hz) flow variations in the mold with detrimental surface velocity variations. Lowering the ruler below nozzle deflects the jets upward, leading to faster surface velocities than the other cases. The double-ruler and no-EMBr cases have the most stable flow. The magnetic field generates largescale vortical structures tending toward two-dimensional (2-D) turbulence. To avoid detrimental large-scale, low-frequency flow variations, it is recommended to avoid strong magnetic fields across the nozzle well and port regions",
author = "R. Chaudhary and Thomas, {B. G.} and Vanka, {Surya Pratap}",
year = "2012",
month = "6",
day = "1",
doi = "10.1007/s11663-012-9634-6",
language = "English (US)",
volume = "43",
pages = "532--553",
journal = "Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science",
issn = "1073-5615",
publisher = "Springer International Publishing AG",
number = "3",

}

TY - JOUR

T1 - Effect of electromagnetic ruler braking (embr) on transient turbulent flow in continuous slab casting using large eddy simulations

AU - Chaudhary, R.

AU - Thomas, B. G.

AU - Vanka, Surya Pratap

PY - 2012/6/1

Y1 - 2012/6/1

N2 - Static electromagnetic braking (EMBr) fields affect greatly the turbulent flow pattern in steel continuous casting, which leads to potential benefits such as decreasing flow instability, surface defects, and inclusion entrapment if applied correctly. To gain a fundamental understanding of how EMBr affects transient turbulent flow, the current work applies large eddy simulations (LES) to investigate the effect of three EMBr ruler brake configurations on transient turbulent flow through the bifurcated nozzle and mold of a liquid-metal GaInSn model of a typical steel slab-casting process, but with deep nozzle submergence and insulated walls with no solidifying shell. The LES calculations are performed using an in-house graphic-processing-unit-based computational-fluid- dynamics code (LES-CU-FLOW) on a mesh of ~7 million brick cells. The LES model is validated first via ultrasonic velocimetry measurements in this system. It is then applied to quantify the mean and instantaneous flow structures, Reynolds stresses, turbulent kinetic energy and its budgets, and proper orthogonal modes of four cases. Positioning the strongest part of the ruler magnetic field over the nozzle bottom suppresses turbulence in this region, thus reducing nozzle well swirl and its alternation. This process leads to strong and focused jets entering the mold cavity making large-scale and low-frequency (<0.02 Hz) flow variations in the mold with detrimental surface velocity variations. Lowering the ruler below nozzle deflects the jets upward, leading to faster surface velocities than the other cases. The double-ruler and no-EMBr cases have the most stable flow. The magnetic field generates largescale vortical structures tending toward two-dimensional (2-D) turbulence. To avoid detrimental large-scale, low-frequency flow variations, it is recommended to avoid strong magnetic fields across the nozzle well and port regions

AB - Static electromagnetic braking (EMBr) fields affect greatly the turbulent flow pattern in steel continuous casting, which leads to potential benefits such as decreasing flow instability, surface defects, and inclusion entrapment if applied correctly. To gain a fundamental understanding of how EMBr affects transient turbulent flow, the current work applies large eddy simulations (LES) to investigate the effect of three EMBr ruler brake configurations on transient turbulent flow through the bifurcated nozzle and mold of a liquid-metal GaInSn model of a typical steel slab-casting process, but with deep nozzle submergence and insulated walls with no solidifying shell. The LES calculations are performed using an in-house graphic-processing-unit-based computational-fluid- dynamics code (LES-CU-FLOW) on a mesh of ~7 million brick cells. The LES model is validated first via ultrasonic velocimetry measurements in this system. It is then applied to quantify the mean and instantaneous flow structures, Reynolds stresses, turbulent kinetic energy and its budgets, and proper orthogonal modes of four cases. Positioning the strongest part of the ruler magnetic field over the nozzle bottom suppresses turbulence in this region, thus reducing nozzle well swirl and its alternation. This process leads to strong and focused jets entering the mold cavity making large-scale and low-frequency (<0.02 Hz) flow variations in the mold with detrimental surface velocity variations. Lowering the ruler below nozzle deflects the jets upward, leading to faster surface velocities than the other cases. The double-ruler and no-EMBr cases have the most stable flow. The magnetic field generates largescale vortical structures tending toward two-dimensional (2-D) turbulence. To avoid detrimental large-scale, low-frequency flow variations, it is recommended to avoid strong magnetic fields across the nozzle well and port regions

UR - http://www.scopus.com/inward/record.url?scp=84861844941&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84861844941&partnerID=8YFLogxK

U2 - 10.1007/s11663-012-9634-6

DO - 10.1007/s11663-012-9634-6

M3 - Article

VL - 43

SP - 532

EP - 553

JO - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science

JF - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science

SN - 1073-5615

IS - 3

ER -