Is this BCRE or Saint-Venant shallow granular flow?

No. It is a minimal 1D lattice toy for slope thresholds, not a continuum PDE solver.

Why 1D columns instead of a 2D heap?

A 1D slice keeps the control simple while still showing relaxation to a slope threshold; extend mentally to axisymmetric heaps.

Angle of repose

Granular piles on a coarse grid relax by toppling excess height to neighbors until local slopes fall below μ = tan α, the angle of repose for a Coulomb-style friction cartoon. Each column stores continuous height; one grain is a unit increment. Relaxation is iterative, similar to cellular automaton sandpile rules used in hazard and animation demos. The green dashed line is a geometric guide for the chosen μ, not a measured output from a continuum PDE.

Who it's for: Introductory friction, geomorphology intuition, and discrete avalanche models.

Key terms

Angle of repose
Sandpile
Coulomb friction
Avalanche
Lattice model

How it works

Discrete sandpile on a 1D lattice: each column stores height. After a grain lands, sand avalanches until no neighbor exceeds μ = tan α (angle of repose). The green dashed line shows the ideal slope for the current μ.

Frequently asked questions

Is this BCRE or Saint-Venant shallow granular flow?: No. It is a minimal 1D lattice toy for slope thresholds, not a continuum PDE solver.
Why 1D columns instead of a 2D heap?: A 1D slice keeps the control simple while still showing relaxation to a slope threshold; extend mentally to axisymmetric heaps.