The goal of the project is to develop a theoretical model capable of predicting the turbulent double-diffusive transport during the continuous alloy ingot casting process, and its implication on macrosegregation. These issues, while critical to meeting demands for enhanced performance of the US aerospace and power industries, have not been properly addressed. The motivation of the work is that for the ingot casting processes of the production scales, their physical sizes and operating conditions cause the convection field to be in the turbulent regime. Consequently, contrary to the information gathered from the small scale laboratory studies that the mushy zone is generally thin everywhere, evidences indicate that turbulent convection makes the instanteous mushy zone thickness and local solutal/thermal distributions vary considerably. The classical way of deducing the materials structure based on the casting speed and mean temperature gradient is largely based on the conduction analysis alone, and hence may no longer be valid for the large scale production. The new model to be developed attempts to address the scaling issue and will be validated by the experimental information specifically designed for the present collaboration. The research will contribute to the production of defect free metal ingots, which will improve the productivity of the ingot casting process.
