Are there long-time tails in granular flows?

TL;DR

This paper investigates the long-time behavior of the velocity autocorrelation function in granular flows using a theoretical model, revealing that the long-time tail vanishes under gravity.

Contribution

It provides a theoretical analysis showing the disappearance of long-time tails in VACF for granular flows influenced by gravity.

Findings

Long-time tail of VACF disappears under gravity

Theoretical analysis based on the optimal velocity fluid model

Long-time behavior differs from non-gravitational cases

Abstract

The long-time behaviors of the velocity autocorrelation function (VACF) for granular flows based on the optimal velocity fluid model are investigated theoretically. It is found the long-time tail of VACF disappears in a granular flow under the gravity.