flow.domain.FlowGrid

flow.domain.FlowGrid(shape, origin, size)

A fixed axis-aligned lattice of cell centres in world coordinates.

Attributes

Name	Type	Description
shape	tuple[int, int, int]	(NX, NY, NZ) cell counts. Flow runs along +Y.
origin	tuple[float, float, float]	World coordinates of the box’s minimum corner.
size	tuple[float, float, float]	World extent of the box along each axis.

Methods

Name	Description
centers	Cell-centre coordinates.
flat_centers	Cell-centre coordinates as a point list.
suggested_epsilon	Half a cell, which puts the interface across about two of them.

centers

flow.domain.FlowGrid.centers()

Cell-centre coordinates.

Returns

Name	Type	Description
	jax.Array	(NX, NY, NZ, 3) world coordinates.

flat_centers

flow.domain.FlowGrid.flat_centers()

Cell-centre coordinates as a point list.

Returns

Name	Type	Description
	jax.Array	(NX*NY*NZ, 3) world coordinates.

suggested_epsilon

flow.domain.FlowGrid.suggested_epsilon()

Half a cell, which puts the interface across about two of them.

sigmoid(-d/eps) runs from 0.12 to 0.88 over |d| < 2 eps, so the transition band is four epsilon wide: half a cell here means two cells of smear. That is the narrowest band the lattice still resolves, and it matters that it is narrow — a wider one never lets chi reach 1 inside a thin fin, so the Brinkman drag never reaches alpha_max and the fin leaks. (Measured on the starter sink at 32x64x32: max chi is 0.85 at one cell diagonal and 0.99 here.)

Returns

Name	Type	Description
	float	The recommended epsilon for :func:solid_fraction.