USP: Unstructured PHOENICS
Click
here for instructions on how to activate unstructured PHOENICS,
or
here for a power-point presentation.
.
The existence of USP frees PHOENICS from its necessity to
employ a structured grid, with consequent advantages of computational economy.
The cells of the unstructured grids which are to be employed are still
predominantly six-sided and, except where obliquely cut by the surfaces
of physical objects, of cartesian or cylindrical-polar shape.
However their faces may have unequal numbers of cells on opposite
sides, usually with on one side and two or four on the other.
One source of economy is the use, in effect, of different grids for different
variables. Thus, if both solids and fluids are present in the same domain, and
the stresses in the solids are not to be calculated, the cells in the solid part
are used only for temperature, because there are no pressures or velocities (or
displacements) to be computed there.
Unstructured PHOENICS and structured PHOENICS exist simultaneously in one
executable;
and they have much in common.
The points of similarity are:
- Problem-set-up data are supplied via a q1 file to the Satellite and via an
eardat file to EARTH;
- The outcomes of the calculation appear in the RESULT and PHI files;
- The graphical output to the monitor is similar in appearance.
The points of difference are:
- USP require additional instructions from the user regarding the grid which
is to be used.
- Formats of the data written to the RESULT and PHI files differ somewhat; and
- For USP, the package recommended for graphical display of the results is
Tecplot, rather than PHOTON or VR-Viewer.
Ready-to-run USP cases
USP is an acronym signifying UnStructured Phoenics.
It denotes the feature of PHOENICS which allows
to use anunstructured grid for its calculations.
This approach facilitates simulation of:
- flows in thin channels,
- calculation in domains containing a large proportion of cells filled with non-participating materials,
- and many other cases in which a fine grid is required only in small regions.