Granular flow over inclined channels with linear contraction

TL;DR

This paper develops and validates a one-dimensional hydraulic model for dry granular flow over inclined channels with contraction, combining theoretical, numerical, and empirical approaches to predict flow regimes.

Contribution

It introduces a novel extended one-dimensional hydraulic theory validated by discrete particle simulations and two-dimensional shallow granular equations.

Findings

The one-dimensional model accurately predicts flow regimes.

The model remains valid despite variations in oblique granular jumps.

Discrete particle method confirms the empirical constitutive law.

Abstract

We consider dry granular flow down an inclined chute with a localised contraction theoretically and numerically. The flow regimes are predicted through a novel extended one-dimensional hydraulic theory. A discrete particle method validated empirical constitutive law is used to close this one-dimensional asymptotic model. The one-dimensional model is verified by solving the two-dimensional shallow granular equations through discontinuous Galerkin finite element method (DGFEM). For supercritical flows, the one-dimensional asymptotic theory surprisingly holds although the two-dimensional oblique granular jumps largely vary across the converging channel.