Granular Flow Under Microgravity: A Preliminary Review

The complex macroscopic rheological behavior of granular flow contains elements of both solid and liquid flow. Furthermore, under microgravity, granular flow exhibits novel flow features. To overcome a lack of comprehensive analyses of granular flow under microgravity, this study reviews the microgravity platforms and devices under which granular flow can be observed, the experimental findings made in such settings, and the range of numerical simulations that can be used to examine granular flow under microgravity. Differences in experimental research between normal gravity and microgravity are highlighted. These differences are found in the modifications made to conventional granular flow experimental devices, in new or unique granular flow behaviors, and in the numerical simulation methods needed for microgravity modeling. Additionally, the benefits of numerical simulation methods for examining rapid and dense flows under microgravity are also discussed. This study may have wide-ranging implications in such fields as investigations of the surface geology of asteroids or the efficient design and development of anchoring mechanisms or space vehicles.