CFD Utilities Files

The surface_patch_utilities module packages a few routines for manipulating
surface grid patches and optional surface data.  It was prompted by a need
to reorganize patches into standard form for comparison of corresponding
results.

centroids_areas   (patchin, patchout)    patchout%xyzf = centroids & areas
clone_grid        (np, nf, grid1, grid2) allocates and copies header info.
match_patch_edges (np, grid, tol)        averages common edge coordinates
patch_data_range  (patch)                assigns patch%xmin/xmax, etc.
reflect_x_y_or_z  (patch, n)             reflects about any coord. plane
reverse_patch_i   (patch, nf)            reverses the i indices
reverse_patch_j   (patch, nf)            reverses the j indices
scale_and_shift   (patch, scale, dx, dy, dz, pout)  scales/shifts x, y, z
surface_connectivity (np, grid, tol, icon)  sets up patch abutment info
surface_vectors   (np,grid,ip,i,j,tani,tanj,unorm) -> unit norm @ ip(i,j)
swap_coordinates  (patch, m, n)          swaps coordinates m and n
transpose_patch   (patch, nf)            swaps i and j in place
update_patch      (patch1, patch2, nf)   transfers patch1 to patch2

04/09/05  D. A. Saunders   Initial implementation for Shuttle cavity grids.
06/16/05     "      "      Added scale and/or shift option.
06/20/05     "      "      Added calculation of cell centroids and areas.
02/22/06     "      "      Premature STOPs on Steve Alter's Opteron were
                           traced to an ier /= 0 test in centroids_areas that
                           should not have been there.
03/31/09     "      "      Added update_patch option.
07/26/10     "      "      %mi, %mj, %mk are now set in centroids_areas
                           in case of I/O via xyzq_io.
09/18/15     "      "      Started adding a surface_vectors utility that
                           produces unique results along patch edges for unit
                           normal vectors (at grid points only, for now).
09/22/15     "      "      Started adding a surface_connectivity utility that
                           is needed by surface_vectors.
09/28/15     "      "      Started adding a match_patch_edges utility, which
                           is really needed first for surface_vectors to do
                           what it promises (unique results at edge points).
10/06/15     "      "      The surface_vectors utility appears to be working
                           in a version of SURFACE_CURVATURE, including
                           averaged unit normals at corner points.  We still
                           don't have more than a stub for match_patch_edges.
11/30/15     "      "      Completed match_patch_edges with match_corners and
                           y0_edges.
05/19/15     "      "      Two glitches were detected when the CONVEX_GRID
                           application made use of surface_vectors:
                           patches reflected about y = 0 DO need to be
                           rectified, and "if (jev == 2)" had iev, not jev.
06/21/21     "      "      The cloning was missing index (ib).
 
For a sample application, see CAPSULE_GRID.  For use of the most recent
surface_vectors and match_patch_edges, see SURFACE_PATCHES.  In particular,
observe the use of first_unit_normal in the "Impose fissures along all
patch edges" option associated with the use of surface_vectors.
See also CONVEX_GRID's use of surface_vectors.