Effect of turbulent heat transfer on continuous ingot solidification

Journal Article · Fri Jan 01 04:00:00 EST 1993 · Journal of Engineering Materials and Technology; (United States)

DOI:https://doi.org/10.1115/1.2902163· OSTI ID:6466751

Shyy, W; Chen, M H ^[1]; Pang, Y; Wei, D Y ^[2]; Hunter, G B ^[3]

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1. Univ. of Florida, Gainesville, FL (United States). Dept. of Aerospace Engineering
2. GE Aircraft Engines, Engineering Materials Technology Labs., Lynn, MA (United States)
3. GE Aircraft Engines, Engineering Materials Technology Labs., Cincinnati, OH (United States)

For many continuous ingot casting processes, turbulent heat transfer in the molten pool plays a critical role which, along with buoyancy and surface tension, is responsible for the quality of the end products. Based on a modified low Reynolds number K-[epsilon] two-equation closure, accounting for the phase change and mushy zone formation, the effect of turbulent heat transfer on the solidification characteristics during titanium alloy ingot casting in an electron beam melting process is investigated. The overall heat transfer rate is enhanced by turbulent transport via two sources, one through the correlated velocity and temperature fluctuations present for both single- and multi-phase flows, and the other through the correlated velocity and release of latent heat fluctuations which are unique to the flows with phase change. The roles played by both mechanisms are identified and assessed. The present turbulence model predicts that although the mushy zone defined by the mean temperature field is generally of substantial thickness as a result of the convection effect, the actual instantaneous zone thickness varies substantially due to turbulence effect. This finding is in contrast to the traditionally held viewpoint, based on the conduction analysis, of a generally thin mushy zone. The impact of turbulent heat transfer on local dendrite formation and remelting is illustrated and the issues involved in model development highlighted.

• OSTI ID: 6466751
• Journal Information: Journal of Engineering Materials and Technology; (United States), Journal Name: Journal of Engineering Materials and Technology; (United States) Vol. 115:1; ISSN 0094-4289; ISSN JEMTA8
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
CASTING
CRYSTALS
DENDRITES
ELECTRON BEAM MELTING
ENERGY TRANSFER
FABRICATION
FLUID FLOW
HEAT TRANSFER
MATHEMATICAL MODELS
MELTING
MULTIPHASE FLOW
PHASE TRANSFORMATIONS
SOLIDIFICATION
TITANIUM ALLOYS
TURBULENT FLOW