The ICEM/KIVA-3(V) interface writes the grid and boundary condition information in a TAPE17 file according the KIVA-3(V) specifications.
Cell Face Boundary Condition (BCL, BCF, BCB):
In MULCAD, set FLAG to FACE to indicate that a "Cell face boundary condition" is being defined, then set ATTRIB to one of the choices allowed (see list below). In the DDN-Mesher interface, set string1 to BCx and string2 to one of the choices below. In P-CUBE, enter one of the allowed choices in the NAME field. The cell face boundary conditions are only recognized on surfaces.
MULCAD DDN-Mesher ------ ---------- 1.FLAG 1.string1 Enter the word BCx 12.ATTRIB 2.string2 Enter one of the face type below _________________________________________________________ Face Type Description BCx value _________________________________________________________ FLUID between 2 fluid cells 4.0 MOVE moving parts 1.0 SOLID walls 2.0 PERIF periodic front 5.0 PERID periodic derriere 6.0 INFL velocity inflow 7.0 OUTFL continuative outflow 8.0 PRESI pressure inflow 9.0 PRESO pressure outflow 10.0 _________________________________________________________Note that BCx can also equal 3.0 if the face is degenerated into an axis. In such case, the interface automatically assigned a BCx of 3.0. By default the interface assigns type SOLID to all non-degenerated wall face, type AXIS to all degenerated wall face and type FLUID for all interior faces. The faces located between two ghost cells always get a BCx of 0.0.
Moving surface specification (IDFACE):
This additional boundary condition is only available for the KIVA-3V file format. The KIVA-3 format allows only one type of moving surface, the piston face. In KIVA-3V however, a mesh may also display other types of moving surfaces such as intake or exhaust valves. Since different moving surfaces may have different motion, an additional parameter, IDFACE, is defined for each face. Note that this option is not available for P-CUBE generated meshes.
IDFACE may take the following values:
Vertex Flag (FV):
In MULCAD, set FLAG to FV to indicate that a "Vertex flag" is being defined, then set ATTRIB to one of the choices allowed (see list below). In the DDN-Mesher interface, set string1 to FV and string2 to one of the choices below. In P-CUBE, enter one of the allowed choices under NAME and select either USER2 or USER3 for the boundary condition type record. The USER2/USER3 flag will permit the translator to distinguish between vertex flag settings and cell face boundary condition settings. The vertex flag (FV) can be assigned to either domains (blocks), subfaces (surfaces) or edges.
MULCAD DDN-Mesher ------ ---------- 1.FLAG 1.string1 Enter the word FV 2.NR 3.integer Option to specify IDFACE 12.ATTRIB 2.string2 Enter one of the flag type below
_________________________________________________________ Flag in ICEM Description FV _________________________________________________________ GHOST inactive vertices 0.0 FACE vertices on piston face 2.0 BOWL bowl vertices, not on piston face 3.0 SQSH vertices in the squish region 4.0 DOME vertices within the head but not touching the head 5.0 HEAD vertices touching the head 6.0 FLUID vertices not described in the above categories 1.0 _________________________________________________________Note that surface tagging overwrites block tagging and edge tagging overwrites surface tagging. The default value for FV is 1.0 for live nodes and 0.0 for ghost nodes.
In MULCAD, set FLAG to REG and enter the region number under entry NR. In the DDN-Mesher Interface, set string1 to REG and enter the region number under integer. In P-CUBE, use the ZONE number to specify the region number. The region number can be defined on the domains (blocks) only. If no regions are defined by the user, all domains are part of region number one. If some domains but not all are given a region number, an extra region is created by the interface with a distinct number and all the remaining domains are included in this extra region.
MULCAD DDN-Mesher ------ ---------- 1.FLAG 1.string1 Enter the word REG 2.NR 3.integer Enter the region numberThe ghost cells are given a region number equals to zero by the interface so this region number should not be used for other regions.
Cell Flag (F):
This flag is equal to 1.0 or 0.0 depending if the cell is live (fluid) or inactive (dead). Unless otherwise specified, all cells generated by the mesher are set to live. If a region needs to be turned off, simply set its vertex flag to GHOST, as shown above.
Note that an extra layer of ghost cells is always created by the translator on the left, bottom and front side of the model.
Option to split the grid:
This option allows to cut the grid in two parts, translate one of the parts and fill the gap created by this split with a number of layers of cells.
The blocks to translate are tagged with the word MOVE. Note that the translation may only be purely in x, or purely in y, or purely in z.
MULCAD DDN-Mesher ------ ---------- 1.FLAG 1.string1 Enter the word MOVEThe user must specify the "split-plane" by tagging the appropriate face(s) with the word SPLIT. All surfaces with this tagging are copied nlayers time to fill the gap created by the translation of part of the mesh.
MULCAD DDN-Mesher ------ ---------- 1.FLAG 1.string1 Enter the word SPLITThe distance to translate the selected blocks and the number of layers of cells to generate are specified in the KIVA-3(V) translator GUI.