DEM simulation of granular segregation in two-compartment system under zero gravity

Abstract

In this paper, granular segregation in a two-compartment cell in zero gravity is studied numerically by DEM simulation. In the simulation using a virtual window method we find a non-monotonic flux, a function which governs the segregation. A parameter  is used to quantify the segregation. The effect of three parameters: the total number of particles N , the excitation strength  , and the position of the window coupling the two compartments, on the segregation  and the waiting time  are investigated. It is found that the segregation observed in zero gravity exists and does not depend on the excitation strength  . The waiting time τ, however, depends strongly on  : Higher the  , lower the waiting time  . The simulation results are important in guiding the SJ-10 satellite microgravity experiments.

Experimental and numerical study on energy dissipation in freely cooling granular gases under microgravity

“…Considering the limitation of the experimental opportunities, we perform simulations based on the discrete elements method (DEM). [45,46] The cell size in the simulation is fixed at 10 cm×10 cm×10 cm. In Haff's theory, the contribution of the energy dissipation caused by friction during collision between particles is not considered; however, in reality, friction exists.…”

Numerical simulations of dense granular flow in a two-dimensional channel: The role of exit position

“…The flow of granular materials has been a research topic of extensive interest in scientific and engineering fields and is involved in many complex phenomena such as avalanches, [1][2][3] mixing and segregation, [4][5][6] and jamming. [7][8][9] When granular flow is confined in a silo with an exit, a typical flow state is the dense granular flow and the most important issue is how to control the flow rate.…”

An instrument for studying granular media in low-gravity environment

“…However, the mechanisms leading to the exchange of particles between the compartments are poorly understood in the absence of gravity. [40][41][42][43] Within a box made of two connected compartments, the separation of a granular system into a cold and dense region on the one hand and a hot and dilute part on the other hand is usually called the Maxwell Demon experiment. On Earth, the apparent intrusion of a Maxwell Demon has been investigated theoretically, 44 experimentally, 45 and numerically.…”

“…Thus, investigations in low-gravity experiments involving compartmented systems are foreseen for next PFCs within the VIP-Gran facility. This study will be complementary to the Chinese SJ-10 satellite mission 47 and will be guided by previous numerical simulations with mono-disperse 42 or bidisperse 43 particles in compartmented systems in the absence of gravity.…”