This document summarizes a student's seminar presentation on developing a computational fluid dynamics (CFD) model to simulate the multi-alloy direct chill casting process. The student reviewed various literature approaches to DC casting modeling. They then described their coupled temperature, fluid flow, and solidification model based on continuum mixture theory. Details of implementing the model in ANSYS CFX were provided. Simulation results of a laboratory-scale multi-alloy DC casting matched experimental measurements and showed the effect of process parameters on sump shape. The model can provide insights to identify appropriate casting conditions.

1. Course- SEMINAR 1 (
Computational model for multialloy casting of aluminiumrolling ingots
BY LOKESH BAVISKAR (M1754005)
Guided by-
DR. R.S.MAURYA

2. Direct Chill (DC) casting

3. DC CO-CASTING MODEL FOR MULTI
ALLOY SYSTEM
The present work focuses on
the development and
validation of a steady-state
computational fluid dynamics
(CFD) model which
appropriately treats heat
transfer, fluid flow and
solidification during multi
alloy casting.

4. Literature review
Weckman and Niessen et al.
Simulated For Steady-state Thermal Condition Of
DC Casting Of A Cylindrical Ingot, Using The Finite
Element Technic
A New Method Of Calculating The Effective Heat
Transfer Coefficient In The Sub Mold Region Of D.C.
Continuously Cast Ingots Cooled By A Free-falling
Film Of Water Was Developed.

5. Literature review
S.K. Das et al.
Developed a steady state DC casting model which is
essentially comprised of a coordinate transformation
philosophy, a non-orthogonal control volume based
discretisation scheme and, a determination of the
location of the solidification front and temperature
field during solidification processing associated with
the DC continuous casting for an al mg alloy system.

6. Literature review
Droste et al.
Developed a coupled 3-D thermo mechanical model,
which employs a heat flux dependent on water flow
rate for the ingot vertical sides.
A continuous weak solidified shell around the ingot is
responsible for the butt curl development.

7. Literature review
Baserinia et al.
A simplified approach for the mold heat-transfer
coefficient [in the DC casting of a rectangular ingot
which is a combination of a one dimensional air gap
model with two-dimensional CFD simulations for
contact heat transfer coefficient (HTC) when the
metal is in perfect contact with the mold.

8. Literature review
Sengupta et al.
They have developed a comprehensive model for
considering primary cooling, secondary cooling with
water ejection and incursion at the inter-face
between the bottom block and the ingot.

9. Literature review
Bennon et al.
 The primary objective is to develop a consistent set of
continuum equations for the conservation of mass,
momentum, energy, and species in a binary, solid-liquid
phase change system.
 In addition to permitting use of the same computational
framework to address a range of multiphase, multi constituent
phase change systems, continuum formulations can be
adapted to single phase problems

10. Coupled temperature fluid flow-
Solidification model
 Continuum Mixture Approach Developed By Bennon And
Incropera
 Modified transport equation to include phase change
phenomena by Bennon
 Contact zone and Air gap zone
 Baserinia air gap predication approach - 1D air gap model
with 2D CFD Simulation for contact HTC
 Calculation of HTC in secondary cooling region

11. Numerical Details
 ANSYS CFX Capability
 Mass fractions are deduced algebraically from the
temperature e.g., tabulated liquid fraction vs. temperature
data which follows Schiel’s equation.
 ANSYS CFX Solver will calculate appropriate average values of
the properties for each control volume in the flow domain, for
use in calculating the fluid flow.
 At the interface of the fluid pairs 1)there is no mass transfer of
the fluids 2) drag force between the fluid pair. 3)it is assumed
that there is no resistance for heat transfer between the fluids.

12. Simulation of laboratory-scale multi- alloy DC
co-casting
AA3003alloy is the core
and AA4045 alloy is clad
Six type-K
thermocouples
Experimental casting
speed of 1.87 mm/s

13. Validation of Temperature field

14. Simulation prediction for(a) sump shape and flow
field (b) temperature profile at the mid-section of
the rolling face

15. Effect of the casting speed on the sump
profiles
 To Avoid Bulk Mixing Of
The Liquid Melt
 At A Casting Speed Of 180
Mm/Min
 Sump Depth Increases with
The Casting Speed

16. Effect of the flow distribution device for multi-
alloy co-casting
 Case 1: a diffuser for the core region and bag filter in the clad
region.
 Case 2: no metal distribution system for the core and clad
region

17. Sump shape and streaklines for the core region

18. Sump shape and streaklines for the clad
region

19. Conclusion
The model predicted sump shape and temperature
profile agrees with experimental observations.
The sump depth for the clad and the core region
linearly increases with the casting speed.
A diffuser, at the end of the feeder tube, should be
used in both core and clad feeding systems so the
metal is more uniformly distributed.

20. Conclusion
The present model is useful in providing the insight
on the thermo-fluid and solidification profile that can
help in identifying appropriate process parameters