Mathematical modelling of the effect of the ‘free fall distance’ on the predicted heat transfer performance in the HSBC process

Horizontal Single Belt Casting (HSBC) is an ecological Near Net Shape Casting (NNSC) alternative to traditional casting processes used in the production of sheet metal alloys. The process principle has been applied at both the pilot and industrial scales to successfully produce aluminum and steel alloy sheets, 5–12 mm thick and 200–250 mm wide, directly from molten metal. This is achieved by high rates of heat extraction, leading to uniform rates of cooling during unidirectional solidification. In the present work, the Computational Fluid Dynamics (CFD) software, ANSYS-Fluent v. 19.0, was used to generate 2D and 3D transient heat transfer models, to study the effect of the ‘free fall’ distance of liquid metal to the cooling belt (from 3 mm to 6 mm), on heat transfer behaviour for several commercial aluminum alloys, during the production of 250 mm wide strips. Additionally, 2D models with moving belts of 1 and 5 metres long were developed to determine the start and end locations for solidification. Wall heat fluxes, ranging between 2.7–3 MW/m2, and wall heat transfer coefficients ranging between 1–2 MW/m2K were obtained from the present simulations, showcasing the heat transfer capabilities of the HSBC process, compared to DC Casting.