Back to Input Deck Cards

GRID

Specifies the discretization scheme to be employed in the simulation.

Required Cards:

TYPE <type>
Grid type (options: structured, structured cylindrical, unstructured (implicit), unstructured_explicit)
NXYZ <int int int>
# of cells in x, y, z dimensions (structured only)
BOUNDS (may not be used with DXYZ)
Specifies bounds of structured Cartesian grid (see examples below)
BOUNDS
  x_min y_min z_min
  x_max y_max z_max
/
Notes:
  1. The origin is automatically calculated based on the lower bound.
  2. Cylindrical grids include only x and z coordinates.
DXYZ (may not be used with BOUNDS)
Specifies grid spacing of structured Cartesian grid (see examples below).
DXYZ
  dx
  dy
  dz
/

Use line continuation through a backslash ‘’ when lines exceed ~80 characters (see DXYZ examples below). PFLOTRAN input can handle lines of 512 characters, but that may change.

FILE <filename>
Name of file containing grid information (unstructured only)

Optional Cards:

GRAVITY <float float float>
Specifies gravity vector (default: 0. 0. -9.8068)
ORIGIN <float float float>
Coordinate of grid origin (default: 0. 0. 0.)
INVERT_Z
Inverts the z axis (positive Z is down instead of default up)

Examples

GRID
  TYPE structured
  NXYZ 5 4 2
  DXYZ
    2@1. 3@1.5
    1@1. 3@0.5
    2@0.25
  /
END
GRID
  TYPE structured
  NXYZ 5 4 2
  BOUNDS
    0. 0. 0.
    100. 50. 25.
  /
END

BOUNDS card with GRID

BOUNDS
 0. 0. 0.
 100. 50. 25.
/

DXYZ card with GRID

DXYZ
  1.
  1.
  0.25
/
DXYZ
  2@1. 3@1.5
  1@1. 3@0.5
  2@0.25
/

DXYZ with continuation:

NXYZ 130 1 9
DXYZ
  0.08 0.09 0.10 0.10 0.12 0.13 0.14 0.15 0.17 0.19 \
  0.20 0.22 0.25 0.27 0.30 0.33 0.36 0.40 0.44 0.48 \
  0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 \
  0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 \
  0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 \
  0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 \
  0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 \
  0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 \
  0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 \
  0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53 \
  0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.64 0.76 0.92 \
  1.10 1.32 1.58 1.90 2.28 2.73 3.28 3.94 4.73 5.67 \
  6.80 8.17 9.80 11.76 14.11 16.93 20.32 24.38 29.26 35.11
  1
  1.666666666666666666667 ! note that all 9 cells in z will be assign 1.666...7.
/

Cylindrical Coordinates

Note: For cylindrical coordinates, the X dimension corresponds to the radius of the cylinder while the Z dimension represents the height. It is assumed that the Y dimension is variable with NY = 1, and no Y grid spacing is specified. PFLOTRAN will calculate the distance in the Y direction automatically based on the cylindrical coordinate system.

GRID
  TYPE structured cylindrical
  NXYZ 100 1 10
  BOUNDS
    0.d0 0.
    100.d0 10.d0
  /
END

But all REGIONs must include Y coordinates of 0 and 1. E.g.

REGION all
  COORDINATES
    0.d0 0.d0 0.d0
    100.d0 1.d0 10.d0
  /
END

REGION top
  FACE top
  COORDINATES
    0.d0 0.d0 10.d0
    100.d0 1.d0 10.d0
  /
END