Selected laboratory benchmarks for validating numerical simulation of casting problems

The complicated physical phenomena which occur within solidifying metals during casting processes can not be easily observed. In the present paper the results of laboratory experiments with mould filling and freezing are presented. The experimental benchmarks have been constructed, based on so called analog fluids which are transparent and have well known physical properties: succinonitrile, polyethylene glycol, water and glycerine. The observed processes were investigated in small rectangular containers: inclined channel with forced flow, freezing at two isothermal, parallel walls; freezing from the top surface in a cubic cavity immersed in hot environment; volumetric freezing in a cube filled with fluid. Optical methods: Particle Image Velocimetry and Thermometry were applied for the flow analysis. Computer supported experimentation combined with digital data recording and processing allowed for the acquisition of a large amount of details on temporary temperature and velocity fields, as well as on phase front position. Herein the attention is focused on some technical problems illustrated by the examples of selected laboratory benchmarks for validating computer codes for casting problems.