A method is presented for finding the osculating circle, and thus the curvature and the normal, of a curve defined by an array of partial volumes. This method is applied, within the framework of an enthalpy formulation. to the analysis of a moving interface separating ice and supercooled water. For short to moderate times the numerical results agree well with available theory; at longer times a morphological oscillation is observed. Such an oscillation was seen in earlier calculations but is not predicted by linearized stability theory. Some speCUlations regarding its origin are offered.
Running title: Curvature and solidificationMailing ad,dress: