La compasión en el marco de la Teoría del Cuidado Humanístico de Jean

Note that all the above operations have an immediate effect on the boundary definitions, reflected by immediate changes to what is displayed in the list.

However, any subsequent boundary changes made outside this dialog, e.g. by issuing commands via the pro-STAR I/O window, will not be listed. To display these changes, click Update List at the top of the dialog.

Boundary Region Definition

Having specified the location of all boundaries in the model, the next step is to

• define their individual type (i.e. set the boundary condition);

• supply information relevant to that type.

The boundary types available at present are:

1. Inlet 2. Outlet 3. Pressure

4. Non-reflective pressure 5. Stagnation

6. Non-reflective stagnation 7. Wall

8. Baffle

9. Symmetry plane 10. Cyclic

11. Free-stream transmissive 12. Transient-wave transmissive 13. Riemann Invariant

14. Attachment 15. Radiation 16. Monitoring

17. Phase-escape (Degassing)

The extent of the information required to define each boundary properly depends in many cases on the variables being solved. For example, in problems using the k-ε model, an inlet boundary needs information concerning the turbulence quantities k andε. In most cases, the appropriate variables are activated automatically as a result of choosing a given modelling option, e.g.

Boundary Region Definition

• In the“Molecular Properties” STAR GUIde panel, the ideal gas option for density will switch the density solver on

• In the“Turbulence Models” panel, any of the K-Epsilon options will switch on the k,ε and viscosity solver

Note that:

1. In the case of a variable such as temperature, you need to switch on the temperature solver explicitly (in panel“Thermal Models”) before proceeding with region definitions.

2. Specification of alternative sets of variables needed to completely define boundaries of type ‘Inlet’ or ‘Pressure’ is possible, as discussed in the sections dealing with such boundaries.

3. It is possible to check for common mistakes in prescribing boundary

conditions (e.g. boundary velocities specified in an undefined local coordinate system) by using the facilities available within the“Check Everything”

STAR-GUIde panel.

4. Boundary regions may be given an optional alphanumeric name to help distinguish one region from another more easily.

The easiest way of applying a desired boundary condition to a given region is via the STAR GUIde system; go to the Define Boundary Conditions folder and open the

“Define Boundary Regions” panel, as in the example shown below:

The number and purpose of the text boxes appearing in the panel and whether they are active or not depends on

• the type of condition selected;

• which variables are being solved for.

Boundary Region Definition

On the other hand, all forms of the panel possess a number of common features, listed below:

1. New regions are defined by:

(a) Selecting an unused region in the boundary regions scroll list (b) Choosing the desired boundary condition via the Region Type menu

options. The effect of this is to immediately display input boxes for supplying boundary values for all flow variables required.

(c) Typing an optional name in the Region Name text box

2. Modification of existing regions is performed in a similar way. The changes are made permanent by clicking the Apply button.

3. Additional boundary regions with identical properties to a pre-defined base region set may also be generated by typing command RGENERATE in the pro-STAR I/O window.

4. Selected region definitions can be deleted by clicking Delete Region.

5. The Compress button eliminates all deleted or undefined regions from the boundary regions scroll list and renumbers the remaining ones contiguously.

6. All free surfaces in your model that are neither defined as boundaries nor explicitly assigned to a region will become part of region no. 0 (shown in the example above). The latter’s properties may be specified in the same way as for any other region. By default, this region is assumed to be a smooth, stationary, impermeable, adiabatic wall.

7. Non-uniform or time-varying conditions may be specified for some boundary types. This is done by choosing one of the following from the Options menu (the default setting, Standard, means constant and uniform conditions):

(a) User — specify the required conditions in one of the user subroutines listed below (see alsoChapter 14):

i) BCDEFI — Inlet ii) BCDEFO — Outlet iii) BCDEFP — Pressure

iv) BCDNRP — Non-reflective pressure v) BCDEFS — Stagnation

vi) BCDNRS — Non-reflective stagnation vii) BCDEFW — Wall or Baffle

viii) BCDEFF — Free-stream transmissive ix) BCDEFT — Transient-wave transmissive

x) BCDEFR — Riemann invariant

The panel also displays a Define user coding button. Click it to store the default source code in sub-directory ufile, ready for further editing.

(b) Table — use values stored in a table file as boundary conditions. The file name is of form case.tbl (seeChapter 2, “Table Manipulation”) and may be entered in the Table Name text box. Alternatively, the file may be selected using pro-STAR’s built-in browser.

Note that whilst one table can be applied to multiple boundary regions, multiple tables cannot be applied to the same boundary region. A list of

Boundary Region Definition

valid dependent variable names that may be used in tables is given for each boundary type in the sections that follow. In addition, the coordinate system used in a table must be the same as the coordinate system

specified for its associated boundary regions.

Table values are actually assigned to a boundary by the STAR-CD solver during the analysis. This is done as follows:

i) Table data are mapped onto the appropriate boundary region in the mesh

ii) Boundary face-centre coordinates are compared with the table coordinates

iii) Variable values at face centres are calculated from the table data using inverse distance-weighted interpolation

iv) The resulting values are assigned to the boundary for the whole duration of the analysis

Figure 4-3 shows an example of using a table to assign boundary conditions to a computational boundary. The coordinates and

user-supplied values are stored at the nodes of the table data grid and the STAR flow variables are stored at the boundary face centres. In the example, boundary values at face centre 1 are calculated as a weighted average of the table data located at ABCD. Similarly, values at face centre 2 are a weighted average of the table data located at EFGH.

Figure 4-3 Mapping and interpolation of table data onto a boundary Please also note the following:

i) It is possible to produce contour or vector plots of the boundary conditions specified by the table, as a means of checking that the table values have been entered correctly. To do this, click Plot Boundary after you have read in the table and then specify which flow variables you wish to plot.

A B

C D

E F

G H

1

2

Boundary face centre Table data node

Table data map Boundary mesh