Transport in Porous Media, Vol.88, No.2, 225-234, 2011
Stability of Moderate Vadasz Number Solutal Convection in a Cylindrical Mushy Layer Subjected to Vertical Vibration
We consider vibration effects on the stability of solutal convection in a mushy layer being cast in a cylindrical geometry. The near eutectic limit is applied and moderate Vadasz numbers are considered to retain the second-order time derivative in the Darcy equation. Since small to moderate radii casting crucibles are the current area of interest, only synchronous modes are analyzed. The results indicate that the presence of vibration in solidifying mushy layers stabilizes the convection, and provides a quantification of the Rayleigh number associated with solutal convection. Of particular interest is the fact that in solidifying systems, the Rayleigh numbers are significantly smaller than that of a passive porous layer.
Keywords:Vibration;Mushy layer;Solutal convection;Solutal Rayleigh number;Froude number;Vadasz number