Dist2Walls: wall distance computation

Version: 2.5 (20/09/2017)

Author: Onera

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Preamble

Dist2Walls gathers efficient algorithms for computing the distance fields for arrays (as defined in Converter documentation) or for CGNS/python tree (pyTrees).

This module is part of Cassiopee, a free open-source pre- and post-processor for CFD simulations.

When using the Converter array interface, a (or b) denotes an array, and A (or B) denotes a list of arrays. Then, Dist2Walls module must be imported:
import Dist2Walls as DTW
When using the pyTree interface, import the module:
import Dist2Walls.PyTree as DTW
In that case, a is a zone node and A is a list of zone nodes or a pyTree.

Module functions

DTW.distance2Walls : computes the distance field from a set of bodies.
compute the distance field located at nodes or centers of zone a (or zones in A), provided a list of surfaces defining the bodies to which the distance is computed.
Two algorithms are available:
- type='ortho' means a distance computed by an orthogonal projection to the surface faces defined by bodies.
- type='mininterf' returns the minimum distance of the point to the vertices of bodies.
If loc='nodes', returns a distance computed at nodes of a (A), else if loc='centers, distance is computed at cell centers of a (A).
Parameter 'signed'=1 enables to compute a signed distance (negative inside bodies).
When using signed distances, each body in bodies list must be a closed and watertight surface.
In array version, cellnbodies provides the 'cellN' field for any vertex in bodies. Default value is 1.
The algorithm 'ortho' does not take into account a body face if cellN=0 for all the vertices of that face.
The algorithm 'mininterf' does not compute the distance to a vertex of cellN=0.
b = DTW.distance2Walls(a, bodies, cellnbodies=[], type='ortho', loc='centers', signed=0, dim=3) .or. B = DTW.distance2Walls(A, bodies, cellnbodies=[], type='ortho', loc='centers', signed=0, dim=3)
In the pyTree version, 'cellN' variable must be stored in bodies directly.
If loc='nodes', the distance field is stored as a 'TurbulentDistance' field located at nodes, and if loc='centers', it is stored in nodes located at centers:
b = DTW.distance2Walls(a, bodies, type='ortho', loc='centers', signed=0, dim=3) .or. B = DTW.distance2Walls(A, bodies, type='ortho', loc='centers', signed=0, dim=3)
Example of use: distance to walls (array), distance to walls (pyTree), dump TurbulentDistance node to a file (pyTree).

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