Transient Flow and Superheat Transport in a CC Mold Pool

Transcription

1 Transient Flow and Superheat Transport in a CC Mold Pool Bin Zhao & B.G. Thomas University of Illinois at Urbana-Champaign University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 1

2 Acknowledgements & Refs. Quan Yuan, P. Vanka, (UIUC) & R. O Malley (formerly AK Steel) CCC, NSF & NCSA Thomas, B.G., R. O'Malley, T. Shi, Y. Meng, D. Creech, and D. Stone, Validation of Fluid Flow and Solidification Simulation of a Continuous Thin Slab Caster, Modeling of Casting, Welding, and Advanced Solidification Processes - IX, Aachen, Germany, August 2-25, 2, P. Sahm, ed., Shaker Verlag GmbH, Aachen, Germany, 2, pp B. Zhao, B.G. Thomas, and P. Vanka, CCC Report, 23 University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 2

3 Outline Validate 3D LES Heat Transport Model with Impinging Jet Experiment Apply Model to thin slab caster Validate through comparison with Temperature measurements in molten pool Breakout shell measurements Thermocouple & water rise measurements University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 3

4 Inlet (uniform velocity and temperature) Impinging jet simulation domain and boundary conditions D r Adiabatic walls 1D x 5D ~1D Impingement plate (constant temperature) 16D Outlet (Convective boundary condition) University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 4

5 Impinging Jet Experiment: Transient velocity and temperature.5 5m/s.4 x(m) y(m).5 T( C) x(m) y(m) University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 5

6 Mean velocity & temperature fields.5 5m/s.5 T( C) x.3 x y y University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 6

7 Mean temperature field.5 T( C) x y University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 7

8 Comparison of measured and computed heat flux 8 Mean RMS Experiment 7 6 Nu/Pr 1/ r/d University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 8

9 Thin Slab Caster (3 port nozzle) Instantaneous and mean temperature field in centerplane Temperature field z.6 Centerplane Animation.6.7 T (K) Narrowface Impingement Animation Top Surface Animation Temperature field z T (K) x x University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas

10 Schematic of plant measurement Ron O Malley, Ya Meng, T. Shi University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 1

11 Temperature measurement T( C) SEN 5 mm Probe insertion Probe withdrawn Profile location Measurement position NF Distance below meniscus (mm) University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 11

12 Temperature measurement T( C) 155 Probe insertion Probe withdrawn Molten flux Molten steel Powder Measurement position Distance below meniscus (mm) SEN 5 mm Profile location NF University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 12

13 Comparison of simulated and measured temperature profile in mold T( C) Profile location 155 Simulation (mean) Probe insertion Probe withdrawn SEN 5 mm Measurement position NF Distance below meniscus (mm) University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 13

14 Heat flux profile down NF Heat flux q (kw/m 2 ) Mean heat flux Heat flux RMS z(m) University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 14

15 Superheat Distribution (k-ε) Superheat (C) Probe (insertion) Probe (withdrawal) Model SEN Profile Location Middle Point Measurement Position NF Distance below the Meniscus (mm) 155 B.G. Thomas, R. O'Malley, et. al., 2. University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 15

16 Mold Temperature Near Meniscus (3D) thermocouple mold top meniscus B.G. Thomas, T. Morthland, 21. water slot Interior view (showing slots) Temperature Predictions University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 16

17 Heat flux profiles from calibrated model Heat Flux (MWm -2 ) B.G. Thomas, R. O'Malley, et. al., Mold hot side -WF Mold hot side -NF Superheat -WF Superheat -NF Distance below Meniscus (mm) University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 17

18 Mold temperatures B.G. Thomas, R. O'Malley, et. al., 2. Cooling Water Temp. Rise Model Calibration Temperature (C) IR WF 325 mm East of CL IR WF 75 mm East of CL IR WF 75 mm West of CL IR WF 325 mm West of CL OR WF 325 mm East of CL OR WF 75 mm East of CL OR WF 75 mm West of CL OR WF 325 mm West of CL CON1D Predicted WF Distance from Top of Mold (mm) Predicted Measured Narrowface 8.2 degc 8.1 Wideface University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 18

19 Effect of superheat on shell growth: Predicted and Measured Shell Thickness (mm) Solidifcation Time (s) East I.R. 86mm from CL West I.R. 86mm from CL East O.R. 86mm from CL West O.R. 86mm from CL CON1D Transient CON1D Steady-State Shell Thickness (mm) Solidifcation Time (s) East Central Narrow Face West Central Narrow Face CON1D Transient CON1D Steady-State Distance below Meniscus (mm) Distance below Meniscus (mm) Wide face Narrow face Thomas, B.G., R. O'Malley, et al, Modeling of Casting, Welding, & Advanced Solidification Processes - IX, Aachen, August 2-25, 2, P. Sahm, ed., Shaker Verlag GmbH, Aachen, Germany, 2, pp University of Illinois at Urbana-Champaign Metals Processing Simulation Lab BG Thomas 19