Granular convection and the Brazil nut effect in reduced gravity

TL;DR

This study investigates how granular convection and the Brazil nut effect behave under different gravity conditions, including Martian and Lunar gravity, revealing that the rise velocity of large beads scales linearly with gravity.

Contribution

The paper provides experimental evidence that granular convection scales linearly with gravity across Earth, Mars, and Moon, extending understanding of granular dynamics in reduced gravity environments.

Findings

Rise velocity scales linearly with gravity

Convection behavior consistent across gravity regimes

Experimental validation in parabolic flight

Abstract

We present laboratory experiments of a vertically vibrated granular medium consisting of 1 mm diameter glass beads with embedded 8 mm diameter intruder glass beads. The experiments were performed in the laboratory as well as in a parabolic flight under reduced-gravity conditions (on Martian and Lunar gravity levels). We measured the mean rise velocity of the large glass beads and present its dependence on the fill height of the sample containers, the excitation acceleration, and the ambient gravity level. We find that the rise velocity scales in the same manner for all three gravity regimes and roughly linearly with gravity.