Abstract: In situ observations of the flow morphology during mold filling under counter gravity are conducted on a perspex water model by means of flow visualization, high speed photography and pattern processing. The experimental results indicate that influences of the dynamic factors on flow morphology can be expressed quantitatively with the parameterφ(k). The flow field takes on different morphology with change in values of φ(k). For thick and thin walled castings, the main dynamic factors influencing flow morphology are gravity and surface tension respectively. Under general circumstances, F_r and W_e should be equal in their values to guarantee the similarity between the prototype and the model in simulating mold filling under counter gravity by experiment.

Key words: casting, mold filling, hydrodynamics