Directional cellular growth of succinonitrile-0.075 wt% acetone bulk samples Part 2: Analysis of cellular pattern

Cellular pattern formation in the system succinonitrile-0.075 wt% acetone i n a supercritical regime is analyzed on the basis of a set of purely diffus ive space experiments in bulk samples. Order-disorder investigations using the minimal-spanning-tree approach yield steady-state patterns for the micr ogravity experiments of an order which suggests a honeycomb structure distu rbed by Gaussian noise. The most important morphology parameter, primary sp acing of the cellular array, is critically discussed in comparison to the e stablished theoretical models. It is found that analytical models fail to d escribe cell sizes in supercritical cellular growth. In contrast, excellent agreement is demonstrated using the numerical model of Hunt. This implies that modelling supercritical cellular growth requires consideration of inte racting solute diffusion fields ahead of the cells and free development of cell shapes, (C) 2001 Elsevier Science B.V, All rights reserved.