Oscillatory instabilities of the liquid and mushy layers during solidification of alloys under rotational constraint
This paper considers the problem of linear flow instabilities due to oscillatory disturbances of the liquid and mushy regions during solidification of binary alloys, under a rotational constraint where the rotation axis is inclined to gravity vector. The governing partial differential equations and boundary conditions are treated numerically in both the liquid and mushy regions, using a novel method proposed by the authors. This method seems to work very efficiently for problems of the present type. The authors present the results of stability analysis and numerical computations for a preferred centrifugal mode of general oscillatory disturbances at zero and non-zero rotation rates. It is found that, at different Prandtl numbers, the spatial locations of the mushy layer tend to form a freckle change as the rotation rate changes. Additionally, it is shown that the preferred oscillatory solution remains unchanged with respect to the change in the sign of the frequency in the absence of rotation, although it changes, generally, in the presence of rotation.
scientific article; zbMATH DE number 1019277