Optimization of riser design in metal casting

A general model for the optimal design of a riser has been formulated and used to obtain explicit formulations for the optimal design of various top and side risers. Analytic solutions for most of the commonly used riser designs have been obtained using a geometric programming approach. Wherever analytic solutions were not possible, numerical solutions using the flexible tolerance technique have been obtained. In the case of the top risers the effect of neglecting the dissipation of heat through the surface area of the casting at its junction with the riser has also been studied. Optimal designs of the top risers provided with necks of different shapes at the base have also been investigated. The effect of providing extra insulation to the riser on its optimal dimensions has also been studied.