02 LIU-R Simulation of Argon Flow through UTN Refractory ...ccc.illinois.edu/s/2011_Presentations/02_LIU-R_Simulation... · ANNUAL REPORT 2011 UIUC, August 18, 2011 Model of Argon

$Page 1: 02 LIU-R Simulation of Argon Flow through UTN Refractory ...ccc.illinois.edu/s/2011_Presentations/02_LIU-R_Simulation... · ANNUAL REPORT 2011 UIUC, August 18, 2011 Model of Argon$
ANNUAL REPORT 2011UIUC, August 18, 2011

Model of Argon Flow through UTN Refractory and Bubble Size EstimationRefractory and Bubble Size Estimation

R. Liu*, B.G. Thomas* and J. Sengupta**

University of Illinois at Urbana-Champaign • Metals Processing Simulation Lab • Rui Liu •

*Department of Mechanical Science and Engineering **ArcelorMittal Global R&D

University of Illinois at Urbana-Champaign ArcelorMittal Dofasco Inc.

Simulation of Argon Gas Flow through UTNthrough UTN

• Purpose of the study:– to gain insight into argon-steel two-phase flow in UTN and SEN,

which greatly influences flow in the mold (especially asymmetric flow)

– to obtain a reasonable initial bubble size distribution in the argon-steel two phase flow in UTN and SEN, which is needed to simulate argon-steel flow in the moldargon-steel flow in the mold

– to run parametric studies of gas injection on the flow pattern

– to evaluate/design UTN geometry / material for optimal gas flow

• This work includes:– Description and validation of two models:

• pressure-source model

• porous-flow model

– Simulation of argon flow through Dofasco UTN

University of Illinois at Urbana-Champaign • Metals Processing Simulation Lab • Rui Liu 2

• Heat transfer analysis

• Gas flow simulation using porous-flow model

Governing Equations-- Pressure-Source Model-- Pressure-Source Model

Darcy’s Law: (1)pKD∇−=vMass Conservation (or continuity): (2)( ) 0=⋅∇ vρHeat Conduction: (3)( ) 0k T∇ ⋅ ∇ =

( ) 0=∇⋅∇ pKDρ ( ) ( ) 0=∇⋅∇+∇⋅∇ pKpK DD ρρ

Ideal Gas Law: (4)( )

p RTρ=

Eqn (1) and (2) ( )pDρ ( ) ( )pp DD ρρ

( ) ( )[ ]pKpK DD ∇⋅∇−=∇⋅∇ ρρ1

p ( ) ( ) SpKRT

pRTpK DD

=

∇⋅

∇−=∇⋅∇

q ( ) ( )

RT

p=ρ( ) ( )p

RTpp DD

-- For Pressure-Source Model pressure diffusion Pressure source due to gas

expansion

• The left hand side of the final equation (in red box) is the standard diffusion term, while the right hand side is in the form of a source term that accounts for the effect of gas expansion due to temperature and pressure gradient.

(


• Add the source term into a FLUENT model of 3-D scalar diffusion (with pressure as the scalar) and solve coupled with a 3-D energy equation

Governing Equations-- Porous Flow Model-- Porous Flow Model

Mass Conservation (or continuity): (1)( ) 0=⋅∇ vρ

F ll S t f N i St k E ti f fl i di

Heat Conduction: (2)

Ideal Gas Law: (3)( ) 0k T∇ ⋅ ∇ =

p RTρ=Full Set of Navier-Stokes Equations for flow in porous media:

viscous resistance0

Re ~2.3, C=0 for laminar flow

( )2 2

40.3 0.0073 4.6 100.035

V

r

ρρ −×∇ ⋅ = ≈ ×Δ

vv

0

( ) ( ) ( ) 12

p Ct

ρ μρ μ ρα

∂ + ∇ ⋅ = −∇ + ∇ ⋅ ∇ + − + ∂

vvv v F v v v

0

1

DK

μα

=

inertial resistance

(steady state problem)

0 0

( )5

42 2

8.1 10 0.0073 4.8 100.035

V

r

μμ−

−× ×∇ ⋅ ∇ = = ×Δ

v

-- Porous-Flow Model• Construct a complete set of 3-D Navier-Stokes equations, with the momentum equation

( )

pKD∇−=v


simplified into equation (1), adopting the ideal gas law to relate density with pressure and temperature. Solve with FLUENT (porous-media flow module) with energy

Permeability (material property model)

Permeability Varying with Temperature:

y ( p p y )

12 21 01 10DSK m−= × (constant specific permeability, from Z. Hashisho, ‘06)

Specific permeability, from ArcelorMittal for MgO or Alumina refractory: 0.8 – 1.2 x10-12 m2

( )DS

D

KK

Tμ=

1.01 10DSK m× (constant specific permeability, from Z. Hashisho, 06)

( )Tμ (gas dynamic viscosity, as a function of local temperature)

)

Viscosity Varying with Temperature:

Dawe ’69*( ) ( )20.63842lg 6.9365/ 3374.72/ 1.51196

0 10 T T TTμ μ − − −= ∗

sity

(P

a*s)

Dawe 69*50 2.228 10 Pa sμ −= × ⋅

Room temperature (20 C) argon ic

Vis

cos

Ref:*R. Dawe and E. Smith. Viscosity of Argon at High

viscosityn

Dyn

am


y g gTemperatures. Science, Vol. 163, pp 675~676, 1969.

Temperature (K)Arg

o

Model Validation --- 3D FLUENT Models

• Test Problem (2 cases)– 1-D problem of gas flowing through a porous medium,

--- 3D FLUENT Models

1 D problem of gas flowing through a porous medium,

– cylindrical coordinate system,

– heat conduction from heated inner surface (fixed at T1) to outer surface (fixed at T2))

– gas injected into outer radial surface, and exits inner surface;

– Effects of varying permeability and dynamic viscosity with temperature on pressure distribution are studied;p ;

– Both pressure and mass flow rate boundary conditions are tested in this simple problem, and three models are implemented for each of the cases.

B.C. for Case 1, fixed pressure: R2, T2, V, (or P)T t lr=R1, P=P1, T=T1; r=R2, P=P2, T=T2.

B.C. for Case 2, fixed gas mass flow rate: r=R1 P=P1 T=T1; r=R2 V=Vi l t T=T2

2, 2, , ( )Total:60000 hexahedral cells

R1 (m) R2 (m) P1 (Pa) P2 (Pa)

0.0375 0.0725 100000 200000

r=R1, P=P1, T=T1; r=R2, V=Vinlet, T=T2.

Symmetric Plane


P1, T1, R1

Symmetric PlaneVinlet (m/s) T1 (K) T2 (K)

0.0073 1800 1000

1-D Test Problem – Matlab Solution

1-D numerical solution is obtained independently via a Matlab code to compare and validate solutions from FLUENTFor the 1-D test problem, the equation above can be written as an ODE, together with the heat conduction equation for heat transfer process:

compare and validate solutions from FLUENT.

g q p

21 0T PP P

T P

′ ′ ′′ ′+ − + =

constant permeability, considering gas expansion

( )1 0

r T P

rTr

′′ =

dPP

dr′ = dT

Tdr

′ =

dP dT

21 0DKT PP P

r T K P

′′ ′′′ ′ + − + + = dK′

considering the thermal effects on both argon permeability and gas expansion

dPP

dr′ = dT

Tdr

′ =

( )1 0

Dr T K P

rTr

′′ =

DD

dKK

dr′ =

Solver uses:Implicit scheme


- Implicit scheme- TDMA method- 2nd central difference scheme

Heat Transfer Calculation Temperature Profile– Temperature Profile

For this 1-D test problem, the heat conduction equation can be solved alone without coupling with any fluid flow equations (one-way coupling assumption)without coupling with any fluid flow equations (one-way coupling assumption). The resultant temperature distribution is shown below:


Argon Viscosity Profileg y

The argon viscosity is related to the local temperature via the correlation stated previously (also below)previously (also below)

( ) ( )20.63842lg 6.9365/ 3374.72/ 1.511960 10 T T T

Tμ μ − − −= ∗2 228 5 *e Pa sμ = −0 2.228 5e Pa sμ =

Room temperature (20 C) argon viscosity


Permeability Profile for Argon Gasy g

The permeability for argon gas flowing through UTN refractory is determined by both the specific permeability and the argon gas dynamic viscosity via theboth the specific permeability, and the argon gas dynamic viscosity via the following relationship:

( )DS

D

KK

Tμ= 12 21.01 10DSK m−= ×


Model Validation CASE 1—using Pressures as B CComparison of Pressure Distribution

(Pressure B.C.) •Both the pressure-source

—using Pressures as B.C.

190000

200000(Pressure B.C.) p

model and the porous-flow model match with solution from the 1-D ODE;

170000

180000

)

ODE;

• Largest pressure gradient is found in the case with

150000

160000

essu

re (P

a) both gas expansion effect and varying viscosity effect

120000

130000

140000Pre

Porous-Flow Model

Pressure-Source Model

1-D ODE Solution

Varying Gas Viscosity

• The shape of the curve for the constant gas viscosity case is irrelevant

100000

110000

120000

NO Thermal Effect

Constant Gas Viscosity of the value of the gas viscosity, as long as it is constant throughout the domain


100000

0.035 0.04 0.045 0.05 0.055 0.06 0.065 0.07 0.075

Radial Position (m)

domain.

Model Validation CASE 2:using Mass Flow Rate as B C-- using Mass Flow Rate as B.C.

Considering gas expansion, argon viscosity varying with temperature

argon viscosity at 1800 K

Ignoring gas expansion, argon viscosity varying with temperature

i i 1000 Kargon viscosity at 1000 K

argon viscosity at 293 K


Dofasco UTN Gas Flow Model Assumptions– Assumptions

Specific permeability units: 1 centi-darcy = 9.869*10-15 m2

1 nPm = 10-13 m2

Argon Flow Rate (SLPM) Specific Permeability (npm)

1.0(for half UTN)

10.1

• Porous-flow model is used in current simulationf d l d h h• Heat transfer is modeled once, then the temperature

field is exported to the porous-flow simulation as a fixed field, due to the assumption of one-way coupling between h t t f d th fl id fl

Porous-flow model:

A d it i ith l l d t t

heat transfer and the fluid flow

- Argon density varying with local pressure and temperature- Argon viscosity varying with temperature- one-way coupling with heat transfer- half of the UTN is adopted as computation domain due to symmetry

University of Illinois at Urbana-Champaign • Metals Processing Simulation Lab • Rui Liu 13Total: 180,000 hexahedral cells

p p y y- both circumferential and vertical gas injection slits are included

Heat Transfer AnalysisyThe heat transfer calculation for the real-world problem is more complicated than the previous test case, still the assumption is adopted that the heat transfer is not affected by the gas flow through the UTN refractory (true if the porosity is not large, maybe less than 50%). The following parameters are calculated/adopted:-- heat transfer coefficients at both outer and inner bore surface;

KN *

24.0880a ρα

μ=Pr

μKNu

h*= baNu PrRe015.05 +=

(Sleicher-Rouse correlation)

+

−=Pr4

88.0a

( )Pr6.0exp5.031 −+=b

ρα

μρUD=Re

inner bore diameter

Parameters Values

Y

μParameters Values

hinner (W/m2K) 2.5*104

h (W/m2K) 10

B.C.:

XZ

17001600

houter (W/m K) 10

Heat conductivityKs (W/mK)

33 hinner houter

Symmetric 1600150014001300120011001000900

μ (Pa*s) 0.0056

ρ (kg/m3) 7200

A t l l it 1 6

yPlane


900Average steel velocity

U (m/s)1.6

Bottom: 0 heat flux

Temperature (K)

Temperature and Argon Density DistributionDistribution

0.3

0.35

0.3

0.35

(m)

0.25

Argon Density(m)

0.25

UT

NH

eig

ht

0.15

0.2

0.560.520.480 44

(kg/m^3)

UT

NH

eig

ht

0.15

0.2

170016001500

Temperature(K)

0.1

0.440.40.360.320.28

0.1

150014001300120011001000

-0 1 -0 05 0 0 05 0 1 0 15

0

0.05

-0 1 -0 05 0 0 05 0 1 0 15

0

0.051000


Radial Position (m)0.1 0.05 0 0.05 0.1 0.15

Radial Position (m)0.1 0.05 0 0.05 0.1 0.15

Pressure Distribution through UTN

0.35

g

0.3

115000

Pressure (Pa)

eig

ht

(m)

0.2

0.25

115000114000113000112000111000110000

UT

NH

e

0.15

0000109000108000107000106000105000

0.05

0.1 104000103000102000

Radial Position (m)-0.1 -0.05 0 0.05 0.1 0.15

0

• Maximum pressure occurs at the conjunction of the “T”-shaped slits• Obvious asymmetry of the pressure distribution is found through the UTN cross section due to the asymmetric


Obvious asymmetry of the pressure distribution is found through the UTN cross section, due to the asymmetric way of injecting gas into UTN• For current case, the maximum pressure found in the domain is about 20 KPa, while the average pressure at the slits is approximately 12 KPa.

Average Velocity Contour at Inner Bore Surfaceat Inner Bore Surface

0.3

0.35

ht

(m)

0.25

Velocity Magnitude(m/s)

UT

NH

eig

h

0.15

0.2

0.0120.0110.010.009

(m/s)

i l i i f d h l i0 05

0.1

0.0080.0070.0060.0050.0040 003 • Maximum velocity is found at the location

corresponding to the conjunction point of the “T”-shaped slits;

Th l it t i th UTN i-0.1 -0.05 0 0.05 0.1 0.15

0

0.05 0.0030.002


• The average gas velocity entering the UTN inner surface corresponding to the circular slit is approximately 5~6 mm/s

Radial Position (m)

Average Normal Velocity Profiles at Different Circumferential Locations

Slice 5

Slice 6Top viewB

Slice 2Slice 3Slice 4Slice 5Slice 6

Slice 7

Different Circumferential Locations

Slice 3

Slice 4Slice 6B

Slice 1

Slice 1

Slice 2Slice 7

vertical slit

circumferential slit

0.009

m/s

)

slice 1, 0 deg (from center plane)

0 006

0.007

0.008

ner

Su

rfac

e (

m

slice 1, 0 deg (from center plane) slice 2, 15 deg slice 3, 30 deg slice 4, 45 deg slice 5, 90 deg slice 6, 135 deg slice 7, 180 deg

0.004

0.005

0.006

city

at U

TN

Inn

0 001

0.002

0.003

No

rmal

Vel

oc

University of Illinois at Urbana-Champaign • Metals Processing Simulation Lab • Rui Liu 18A

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.400.000

0.001

Ave

rag

e

Distance from UTN Bottom (m)

Validation via Static Test

water tankwater tank

upper ring

Static bubbling test

0.01200 0110

Velocity Magnitude(m/s)

Vertical slit at outer surface

0.01100.01000.00900.00800.00740.00700.00630 0060

Gas injection point (at o ter


0.00600.00580.00570.0056

point (at outer surface)

Comparison of Bubble Distribution on UTN Inner Surface

XY

on UTN Inner Surface

ZVelocity Magnitude(m/s)

0.0120.0110.010.009

( )

0.0080.0070.0060.0050 0040.0040.0030.0020.001


Methodology of Bubble Size Estimation in Argon Steel System

Calculate the Gas Calculate Gas Volumetric via solving a Porous-Flow /Pressure-Source model for

Estimation in Argon-Steel System

Velocity profile at UTN/SEN inner surface

Flow Rate in Hot Condition at Stopper-Rod Tip

average normal velocity at UTN inner surface (described previously)

via empirical equation from G. Lee and B.G. Thomas

Estimation of Active Sites for gas injection at UTN and SEN refractory

for gas injection at stopper-rod tip

Number Distribution

Calculation of Gas Flow Rate per Active Site (Total Flow Rate/cm2)/(Active

sites #/cm2)Bubble formation at downward nozzle

Estimation of Mean Diameter

via two-stage model from H. Baiand B.G. Thomas

has been studied by H. Tsuge et al.


Estimation of Mean Diameter of Initial Bubble Formation

Estimation of Active Sites Number in UTN/SEN Refractoryin UTN/SEN Refractory

from ref [1][ ]

from ref [1]

G. Lee and B.G. Thomas suggest[1]:

So the number of active sites per cm2

is:Where:Qg: the gas injection flow rate per cm2 (LPM);U: liquid superficial velocity (m/s);

0.2635 0.85 0.33087 g ermsite

Q U PN

θ=

is:


U: liquid superficial velocity (m/s);Perm: material permeability (npm);θ: contact angle for wettability (rad)

Ref:[1] G. Lee, B.G. Thomas, et al., Met. Mater. Int., Vol. 16, No. 3 (2010), pp. 501~506

Calculation of Gas Flow Rate per Active Siteper Active Site

0.73651Q Q θAdopting the active sites number correlation at UTN inner surface:

0 2635 0 85 0 33087Q U P0.7365

0.85 0.3308

17

g gsite

site erm

Q QQ

N U P

θ= =

0.2635 0.85 0.33087 g ermsite

Q U PN

θ=

Flow Rate per Active Site(LPM)

0.060.0550.050.0450.04

7.56.5

Active Sites Number(#/cm^2)

0.00750.00650 0055

Average Normal Velocity(m/s)

0.0350.030.0250.020.0150.01

5.54.53.52.51.50 5

0.00550.00450.00350.00250.00150.0005

Y

0 00.005

Y

0.5

Y


X

Z

X

Z

X

Z

Estimation of Mean Bubble Size using a Two-Stage Modelusing a Two-Stage Model

Hua’s two-stage initial bubble formation model[2]:

1 Expansion stage (solving for r as r )1.Expansion stage (solving for r, as re)

Drag coefficient:Drag coefficient:

Bubble Reynolds number:

Based on the 1/7th law in turbulentBased on the 1/7 law in turbulent flow in the circular pipe

Contact angle function: Empirical correlation with liquid steel

fi i l l itExpansion stage Elongation stage

Active sites function as drilled holes where gas is injected. So based on the

--Figures from ref [2]2.Elongation stage (solving for rd)

superficial velocityExpansion stage Elongation stage

g jnumber of active sites and gas flow rate over an area, the gas flow rate per active site can be determined.

no le inner diameter (m)D :liquid steel superficial velocity (m/s)U


Ref:[2] B. Hua and B. G. Thomas, Metall. Mater. Trans. B 32, 1143(2001).

:nozzle inner diameter (m)

lρ :liquid density (kg/m3)

gρ :gas density (kg/m3)

ND :liquid steel superficial velocity (m/s)U:surface tension (N/m)σ:kinematic viscosity of liquid steel (Pa*s)υ

Estimation of Bubble Size Distribution


Model Application:Gas Leakage PredictionGas Leakage Prediction

• Parameters for this process:p– Casting speed: 40 ipm

– Mold width: 72 inches

– Mold thickness: 10 inches

– Submergence depth: 8 inches

Dithering amplitude: 14 mm or 7 mm– Dithering amplitude: 14 mm or 7 mm

– Dithering frequency: 0.4 Hz

– Total gas injection flow rate: ~20 SLPMg j

– Back Pressure: 19 psi

– SEN inner bore diameter: 80 mm

– Plate diameter: 75 mm

– SEN bottom shape: Cup bottom

• Gas injection flow rate into the nozzle can be determined


• Gas injection flow rate into the nozzle can be determined by modeling the hot system while considering leakage.

Estimation of Gas Flow Rate Entering NozzleEntering Nozzle

• Both argon flow rate and back pressure are measured, though one and only one of these two values is needed to define the problemone of these two values is needed to define the problem

• Use back pressure as B.C. for the porous-flow model to calculate gas flow rate into the nozzle inside.

• Difference between measured total gas flow rate and calculated gas flow• Difference between measured total gas flow rate and calculated gas flow rate into the nozzle reveals the amount of gas leakage

Numerical Model set up:

B C fixed pressure: r=R1 P=P1 T=T1; r=R2 P=P2 T=T2

Heat transfer model coupled porous flow model, with pressure at inner and outer bore surface as boundary conditions.

B.C. fixed pressure: r=R1, P=P1, T=T1; r=R2, P=P2, T=T2.

R1 (m) R2 (m) P1 (Pa) P2 (Pa) T1 (K) T2 (K)

0.04 0.0875 84672 131000 1832 1200

Refractory (specific) permeability (m2): 1.01*10-12

Argon dynamic viscosity (Pa*s): ( ) ( )20.63842lg 6.9365/ 3374.72/ 1.511960 10 T T T

Tμ μ − − −= ∗


g y y ( ) ( ) 0μ μ5

0 2.228 10 *Pa sμ −= ×Room temperature (20 C) argon viscosity

Pressure/Velocity Distribution of Gas Flowing Through Heated UTN WallFlowing Through Heated UTN Wall

Simulation suggests 30 LPM argon entering nozzle (hot condition)

2.84e-02

2.73e-02

2.62e-02

2 51e-02

entering nozzle (hot condition)

2.51e-02

2.40e-02

2.29e-02

2.18e-02

2.07e-02

1.96e-021.96e 02

1.85e-02

1.74e-02

1.63e-02

1.52e-02

1.41e-02

1.30e-02

1.19e-02

1.08e-02

9.75e-03

8.65e-03

7.56e-03

6.46e-03

Radial Velocity (m/s)Note:

contour is just for velocity

University of Illinois at Urbana-Champaign • Metals Processing Simulation Lab • Rui Liu 28Note: pressure shown in the contour is the gauge pressure

contour is just for velocity vectors

Only about 25% of the total gas enters the nozzle

Temperature and Viscosity ProfilesTemperature Profile across UTN Wall

1900

Argon Viscosity Profile across UTN Wall

8.50E-05

p y

1600

1700

1800

atu

re (

K)

7.50E-05

8.00E-05

co

sit

y (

Pa

*s)

1300

1400

1500

Te

mp

era

6.50E-05

7.00E-05

Arg

on

Vis

c

Velocity Profile across UTN Wall

0.03

12000.035 0.045 0.055 0.065 0.075 0.085

Radial Position (m)

6.00E-050.035 0.045 0.055 0.065 0.075 0.085

Radial Position (m)

Gauge Pressure Profile across UTN Wall

50000

0.02

0.025

y (

m/s

)

30000

35000

40000

45000

re (

Pa

)

0.01

0.015

Arg

on

Ve

loc

ity

10000

15000

20000

25000

Ga

ug

e P

res

su

r


0.005

0.01

0.035 0.045 0.055 0.065 0.075 0.085

Radial Position (m)

0

5000

10000

0.035 0.045 0.055 0.065 0.075 0.085

Radial Position (m)

Geometry and Meshy

~250 mesh blocks


Total mesh:1 million mapped hexa-cells

Computation Detailsp

Models and Schemes Name

Turbulence Model k-epsilon with std. wall functions

Multiphase Model Eulerian ModelMultiphase Model Eulerian Model

Advection Discretization 1st order upwinding

Meniscus Domain Outlet

No-slip wall Pressure outletB.C.:

Bubble size: 2.4 mm Time step: 0.05 sec

Total mesh: 1.0 million mapped hexa- cells

S d Si kSources and Sinks:Mass and momentum sinks are utilized for solidification of liquid steel adjacent to shell,


and escape of argon gas adjacent to meniscus

Half mold was used as computational domain.

Argon Flow Pattern at Center Plane between Wide Facesbetween Wide Faces

Gas Velocity (m/s)

Gas taking liquid steel to meniscus(buoyancy force dominated flow)

Gas taken by liquid steel jet once coming out of ports, then rising to meniscusmeniscus

120 LPM argon flow rate (hot)(20 SLPM with no leakage)

30 LPM argon flow rate (hot)(20SLPM with 75% leakage


based on porous flow model results)

Liquid Steel Flow Pattern at Center Plane between Broad FacesPlane between Broad Faces

Single Roll Flow Pattern Double Roll Flow Pattern g

120 LPM argon flow rate (hot)(20 SLPM with no leakage)

30 LPM argon flow rate (hot)(20SLPM with 75% leakage


( gbased on porous flow model results)

Steady State Flow Patterns at Different Gas Injection RateGas Injection Rate

(m)

0.20.260.210 5

Horizontal Velocity (m/s)m/s Single Roll Flowfl t d f

ick

ne

ss

0

0.150.100.05

-0.01-0 06

0.5 m/s

120 LPM hot argon

Single Roll Flow Pattern

flow towards narrow face

Mo

ldT

h 0 -0.06-0.11-0.17-0.22

gflow rate (no leakage)

Distance from Mold Center (m)0 0.2 0.4 0.6 0.8 1

-0.2

m)

0 20.26

Horizontal Velocity (m/s)

ck

ne

ss

(m 0.2 0.210.150.100.05

-0.01

0.5Horizontal Velocity (m/s)

m/s Double Roll Flow Pattern

flow towards SEN

Mo

ldT

hic 0

0.01-0.06-0.11-0.17-0.22

30 LPM hot argon flow rate(75% leakage)

University of Illinois at Urbana-Champaign • Metals Processing Simulation Lab • Rui Liu 34Distance from Mold Center (m)

M

0 0.2 0.4 0.6 0.8 1-0.2

(75% leakage)

Conclusions

• Nice matches are achieved among the 1-D ODE l ti d l dsolutions, pressure-source model and porous-

flow model for the test problems, with the f ll i f t id dfollowing factors considered:– expansion of heated gas

– argon viscosity change with temperature

• Validated models of argon flow through heated UTN can be utilized to predict:– asymmetry of gas distribution at UTN inner surface, for

design optimization purpose

– initial bubble size combined with bubble size models (by H Bai and G Lee)


(by H. Bai and G. Lee)

– argon gas leakage, which greatly changes flow pattern

Acknowledgements

• Continuous Casting Consortium Membersg(ABB, ArcelorMittal, Baosteel, Tata Steel, Magnesita Refractories Nucor SteelMagnesita Refractories, Nucor Steel, Nippon Steel, Postech, Posco, SSAB, ANSYS Fluent)ANSYS-Fluent)

• Hongbin Yin, Bruce Forman and Yong Lee from ArcelorMittal global R&D at East Chicago

• Other graduate students in Metals Processing• Other graduate students in Metals Processing Simulation Lab


Documents

02 LIU-R Simulation of Argon Flow through UTN Refractory ...ccc.illinois.edu/s/2011_Presentations/02_LIU-R_Simulation... · ANNUAL REPORT 2011 UIUC, August 18, 2011 Model of Argon