Flow Behavior of Grains through the Dosing Station of Spacecraft under Low-Gravity Environments

Abstract

For the design of the grain-processing stations of spacecrafts, such as EXOMARS 2020, reliable estimates are required on the internal and bulk flow characteristics of granular media under low-gravity environments. Using theoretical and computational modeling, the authors present the results on the generic flow behavior of granular materials through flow channels under different gravity levels. For this, the authors use three approaches: (1) a simple one-dimensional discrete-layer approach (DLA) based on hybrid-Lagrange continuum analysis; (2) Kirya’s three-dimensional structural continuum model; and (3) three-dimensional discrete-element modeling (DEM). Each model has its merits and limitations. For the granular simulant considered in this paper, a good level of agreement is obtained between the results of Kirya’s model and the DEM simulations on the flow properties of the grains. Some qualitative comparisons are also reported favorably on the flow characteristics of grains between the results of the experimental parabolic flight campaign and the DEM simulations. The theoretical and DEM simulations presented in this paper could help to minimize relying on the complex experimental programs, such as the parabolic flight campaign, for evaluating the processing behavior of grains under low-gravity environments in the future.