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A numerical model of the entire casting process starting from the mould filling stage to complete solidification is presented. The model takes into consideration any phase change taking place during the filling process. A volume of fluid method is used for tracking the metal–air interface during filling and an enthalpy based macro-scale solidification model is used for the phase change process. The model is demonstrated for the case of filling and solidification of Pb–15 wt%Sn alloy in a side-cooled two-dimensional rectangular cavity, and the resulting evolution of a mushy region and macrosegregation are studied. The effects of process parameters related to filling, namely degree of melt superheat and filling velocity on macrosegregation in the cavity, are also investigated. Results show significant differences in the progress of the mushy zone and macrosegregation pattern between this analysis and conventional analysis without the filling effect.

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A numerical investigation of turbulent flows through a solar air heater roughened with semicircular sectioned transverse rib roughness has been executed. The physical problem is represented mathematically by a set of governing equations, and the transport equations are solved using the finite element method. The numerical results show that the flow-field, average Nusselt number, and average friction factor are strongly dependent on the relative roughness height. The thermohydraulic performance parameter is found to be the maximum for the relative roughness height of 0.042. Comparisons with previously published work are performed and were found to be in excellent agreement.