jaxdem.domains.reflect_sphere#

Reflective boundary-condition domain.

Classes

ReflectSphereDomain(box_size, anchor)

A Domain implementation that enforces reflective boundary conditions only for spheres.
class jaxdem.domains.reflect_sphere.ReflectSphereDomain(box_size: Array, anchor: Array)[source]#

Bases: Domain

A Domain implementation that enforces reflective boundary conditions only for spheres. We have this dedicated version for performance reasons.

Particles that attempt to move beyond the defined box_size will have their positions reflected back into the box and their velocities reversed in the direction normal to the boundary.

Notes

  • The reflection occurs at the boundaries defined by anchor and anchor + box_size.

static apply(state: State, system: System) → Tuple['State', 'System'][source][source]#

Applies reflective boundary conditions to particles.

Particles are checked against the domain boundaries. If a particle attempts to move beyond a boundary, its position is reflected back into the box, and its velocity component normal to that boundary is reversed.

\[\begin{split}l &= a + R \\\\ u &= a + B - R \\\\ v' &= \\begin{cases} -v & \\text{if } r < l \\text{ or } r > u \\\\ v & \\text{otherwise} \\end{cases} \\\\ r' &= \\begin{cases} 2l - r & \\text{if } r < l \\\\ r & \\text{otherwise} \\end{cases} \\\\ r'' &= \\begin{cases} 2u - r' & \\text{if } r' > u \\\\ r' & \\text{otherwise} \\end{cases} r = r''\end{split}\]
where:

  • \(r\) is the current particle position (jaxdem.State.pos)

  • \(v\) is the current particle velocity (jaxdem.State.vel)

  • \(a\) is the domain anchor (Domain.anchor)

  • \(B\) is the domain box size (Domain.box_size)

  • \(R\) is the particle radius (jaxdem.State.rad)

  • \(l\) is the lower boundary for the particle center

  • \(u\) is the upper boundary for the particle center

TO DO: Ensure correctness when adding different types of shapes and angular vel

Parameters:

  • state (State) – The current state of the simulation.

  • system (System) – The configuration of the simulation.

Returns:

The updated State object with reflected positions and velocities, and the System object.

Return type:

Tuple[State, System]

Note

  • This method donates state and system

  • Only works for states with ONLY spheres.