### 10.9.21. Parts - Zoning - Refine

This window lets you refine structured Lagrange, ALE, Euler-Godunov
and Euler-FCT parts. However, the part must satisfy the following
requirements in order to utilize this new refining facility:

The part must be a 'box' type object.

The X, Y, and Z coordinates of the grid nodes must
increase with the I, J, and K indices respectively.

**I/J/K Factor**

Enter the Refine Factor for the I/J/K index; that is, number
of the new cells created from an original single cell in that direction.

The refining algorithms are by default applied to all cells
within a part. In order to limit the range of cells within a part
that undergo refinement, you can select an appropriate IJK-RANGE first.
In addition it should be noted that the following limitations apply
to the refinement of Euler and ALE parts.

For simplicity with multi-material Euler-Godunov grids,
the material volume fraction of an original cell is assigned to all
the new cells created from that original cell. Thus the material interface
on the new grid may not be exactly the same as that on the original
grid.

For ALE grids, the original motion constraint of the
ALE nodes is not retained during the refining procedure. The motion
constraint for all the new nodes is set to Lagrange, even if the constraint
of the original node is, for example, Equipotential. You will therefore
need to redefine the motion constraints for ALE parts following the
refining process.

The cell index for time history gauge points is also updated
during the refinement. Furthermore, the mass is always conserved between
the original and refined parts. However, the momentum and kinetic
energy in Lagrange and ALE parts may not be conserved exactly because
the mesh refinement modifies the nodal masses and thus affects the
momentum and kinetic energy calculation. For Euler-Godunov and Euler-FCT
parts, since the cell mass is used to calculate both the kinetic energy
and momentums, refinement does not affect the calculation. The kinetic
energy and momentums should therefore always be conserved.

An example of the refinement of a Lagrangian part is shown below.
Note that the refinement factors IFACT, JFACT and KFACT have been
set to 1, 2 and 3 respectively.