Abstract
A numerical technique of solidification analysis is presented which is based on "Inner Nodal Point Method" and takes account of fluid flow induced by solidification shrinkage and variable fluid density. As examples. solidifications of tapered steel ingots have been analysed. It is shown that (1) a step by step method, where the equations of conservation laws for heat- and fluid-flow are solved alternately, can be employed, (2) the value of permeability in solid-liquid region affects considerably the magnitude of fluid velocity, pressure and rate of solidification, (3) the magnitude of negative pressure and rate of solidification decrease with increasing taper, and (4) the movement of solid phase should be considered in some cases. In addition, the mechanisms of formation of V- and A-segregation are discussed on the flow and pressure field calculated. The proposed technique, which can handle complicated boundary shape, may be more useful for the determination of ingot shape and casting condition than conventional ones.
