Rensselaer Isothermal Dendritic Growth Experiment

The Rensselaer Isothermal Dendritic Growth Experiment (RIDGE) is a continuation of the Isolated Dendritic Growth Experiment (IDGE), which flew on three space flight experiments aboard the space shuttle Columbia. The RIDGE is an extension to the completed flight experiments by IDGE, to further investigate phenomenon uncovered in the analysis of data obtained by these earlier efforts. The first two space flight experiments, USMP-2 and 3, were conducted with succinonitrile (SCN) as the growth material. Analysis showed that SCN dendrites closely followed the predictions of Ivantsov for dendrites grown in convection free environments, but with important differences. The third microgravity experiment, USMP-4, used pivalic acid, (PVA), a more anisotropic material, for the growth medium. Preliminary analysis found that, while existing solidification theories could closely predict the growth of SCN dendrites the approximation was not as good for pivalic acid. The third flight experiment was equipped with a video capture system. Data obtained from the captured video contained approximately 30 frames per second of data, over the entire growth process. Initial analysis of the video has shown that the dendrites grown in PVA exhibit a time dependent growth characteristic and may not always have reached steady-state growth during the experiment. The purpose of this paper will be to present continued analysis of the characterization of PVA dendrites as well as further in-depth analysis of the data obtained from the video images captured on the final flight experiment.