;;;File-name: output.tut


    

***************************************************************** TUTORIAL on Non-Graphics Output from PHOENICS *****************************************************************

Contents -------- 1. An example: library case 248 2. Changing the print-out of "spot" values and residuals 3. Changing the print-out to the screen 4. The use of RESTRT or AUTOPS 5. Changing the print-out of "field" values 6. Changing the print-out of "profiles" 7. Changing the print-out of "contours" 8. Other output facilities

Preface ------- In order to understand this tutorial it is important to read the preface to the companion tutorial, entitled: "Non-Menu Data Input to PHOENICS".

In the present case, the first line of the otherwise-excised screen displays between the VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV and ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ lines has been retained so as to provide a context for the interspersed comments. -----------------------------------------------------------------

----------------------------------------------------------

. An example: library case 248 *******************************

>>> The lecture on data input to PHOENICS introduced case 248 of the Input-File Library. In the first section of the present lecture, the computer output corresponding to that case will be presented and discussed in a preliminary way. Thereafter detailed attention will be given to the commands which controlled the print-out, and to how they may be altered.

>>> Library case 248 is a modification of case 247, which in turn is a modification of case 244. The description of case 244 can be brought to the screen by the command SEELIB 244. A relevant extract is:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV GROUP 1. Run title and other preliminaries ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The description showing the relevant feature of case 247 is shown by an extract of the response to the command SEELIB 247:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV TEXT(PIPE WITH INTERNAL RESTRICTION ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> A rough sketch of the geometry is as follows:

__________________________________________wall________ . | ^ . . |plate | . . | y-direction . .inlet outlet. . orifice . - - - - - - - - - - - - - - - - - - - - - axis - - - - z-direction -->

A related extract from the message following SEELIB 248 is:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV GROUP 1. Run title and other preliminaries ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> Other features which can be recognised by inspecting the input file reproduced in the previous lecture are:-

* the flow is steady; * laminar conditions are presumed; * only one phase is present; * the thermophysical properties of the fluid are uniform; * the fluid flows from small z to large; * the y-direction is radial; * the fluid enters the duct at z=0.0 at a prescribed rate, and leaves at z=0.2 under the influence of a prescribed-pressure boundary condition. * in addition to heat transfer between the fluid and the wall, a mass-transfer process takes place, in which three substances, A, B and C, having different diffusion coefficients, diffuse from the pipe wall.

>>> The results presented below will be commented upon by way of interspersed notes. These can be distinguished from the PHOENICS print-out, by their employment of lower-case characters. The VVVVV and ^^^^^ dividing lines will provide further indications.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV CCCC HHH PHOENICS VERSION 1.4, 23 JULY 1987 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The above "boiler-plate" information changes from time to time and from installation to installation.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV ***------ STORAGE INFORMATION ------*** ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The first two entries show that more than enough storage was provided for the numbers of cells and variables in question. Had NZ been set at 100 rather than 20, since 5x10251 exceeds 50000, PHOENICS would have automatically moved itself into the out-of-core mode of operation.

Since the latter mode is slower, the user might decide to avoid its being activated by increasing the F-array dimension. Typing DIMENS during satellite interaction will elicit advice on how to do this.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV GROUP 1. RUN TITLE & NUMBER ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> Here the title of the run is printed, exactly as it would be by the SEE 1 command during satellite TALKing.

If, in the Q1 file, the statement ECHO=T had been provided, "SEE" print-out would have been provided for all 24 data groups.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV IRUNN = 1 ;LIBREF = 244 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The cell-centre coordinates are printed above.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV --- INTEGRATION OF EQUATIONS BEGINS --- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> YZPR means that the dependent-variable field values will be printed in blocks corresponding to y-z planes. This is automatic when NX=1, as here; otherwise it is a user option. (See "help" entry YZPR)

Values are printed only for z-planes 4 through 8, because of the settings IZPRF=NZ/4-1(=4);IZPRL=NZ/4+3(=8) in Group 23 of the Q1 file. Similarly, the setting IYPRF=NY/2-1(=9) has suppressed print-out of values for IY=1 through IY=8. This has enabled attention to be concentrated on the region close to the orifice plate.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV FIELD VALUES OF P1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The orifice plate lies between "slabs" 5 and 6. This explains why the pressure changes from positive to negative there. The outlet pressure is set to zero; so there is a pressure recovery, as expected, in the downstream half of the pipe.

>>> The greater pressure at large y than at small must be due, at least in part, to the swirl-velocity component of the incoming stream.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV FIELD VALUES OF U1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The swirl velocity is lowest at IY=20, no doubt because of friction caused by the wall located at large y.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV FIELD VALUES OF V1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The negative V1's correspond to the contraction of the flow upstream and slightly downstream of the orifice.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV FIELD VALUES OF W1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The very small W1's (i.e. z-direction velocities) at IZ=5 are the consequence of the presence of the orifice plate, downstream of which a recirculation exists, as indicated by the negative W1's.

The largest value printed is at IZ=5 (the orifice plane) and IY=9 (i.e. within the orifice opening).

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV FIELD VALUES OF H1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The enthalpy of the fluid (H1) is zero at entry, and 1.0 at the wall. The considerable uniformity of the H1 values downstream of the orifice plate can be explained by the presence of the above- mentioned recirculation.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV FIELD VALUES OF C ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> C, B and A represent concentrations of species having the Prandtl/Schmidt numbers indicated by the Q1-file entry (GROUP 9):

PRNDTL(A)=1.0;PRNDTL(B)=0.1;PRNDTL(C)=10.0

They are all given values of zero at inlet and 1.0 at the wall.

>>> As is to be expected, values of C are lowest and those of B are highest, because the diffusion coefficients of the substances increase in that order.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV FIELD VALUES OF B

FIELD VALUES OF A

WHOLE-FIELD RESIDUALS BEFORE SOLUTIONS

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> This is a fairly-well converged run, because nearly all the normalised residuals are below unity.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV NET SOURCE OF U1 AT PATCH NAMED: INLET = 2.500E-07 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> Among the items of information to be gleaned from the above table is the fact that the sources at the wall are in the order:

B (highest) H1 A C(lowest).

This order is the opposite of that of the Prandtl/Schmidt numbers, as expected.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV SPOT VALUES VS. SWEEP (/ITHYD IF PARAB) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> This plot shows how the values of the dependent variables change with each successive solution sweep at a monitor point, whose location is determined by the values of IYMON and IZMON.

>>> The values from about sweep 16 appear to be remaining fairly steady. However to ensure that these were values corresponding to a converged state, the setting for LSWEEP ought to be made larger to see whether these are steady values at sweep numbers higher than 20.

>>> The frequency of printout in terms of sweeps is controlled by NPLT, which was set to unity in this case. In section 2, settings will be introduced which will allow significant modification to the appearance of this plot.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV RESIDUALS VS. SWEEP (/ITHYD IF PARAB) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> This plot shows how the values of the residuals change with sweep. The frequency of printout for residuals is also affected by NPLT. In section 2 settings will be introduced to affect the appearance of this plot.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PATCH(EXIT ,PROFIL, 1, 1, 1, 20, 19, 19, 1, 1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> This plot shows profiles of several of the dependent variables along a radial line close to the exit.

Understandably, W1 has its largest value on the axis, whereas the concentration variables have theirs at the wall.

The substance B, which has the smallest Prandtl/Schmidt number, has diffused so easily that the range between minimum and maximum value in the plot is the smallest, whereas for substance C the range is the largest.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PATCH(PIPE ,CONTUR, 1, 1, 1, 20, 1, 20, 1, 1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> Like all the line-printer contour plots in this file, the whole of a plane through the pipe axis is covered. The general direction of flow is upward on the diagram.

The radial direction is horizontal, positive to the right. The wall is therefore represented by the right-hand edge, marked by N's, and the axis by the left-hand edge, marked by S's.

>>> This plot shows that the largest values of the swirl component of velocity, U1, are to be found near the axis

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PATCH(PIPE ,CONTUR, 1, 1, 1, 20, 1, 20, 1, 1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> This plot shows clearly how the presence of the orifice plate, situated one quarter of the distance from the bottom of the diagram to the top, has a dramatic effect on the distribution of the axial component of velocity.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PATCH(PIPE ,CONTUR, 1, 1, 1, 20, 1, 20, 1, 1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The enthalpy contours have a somewhat similar shape to those for W1; but of course H1 cannot exhibit both positive and negative values as W1 can.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PLOT(PIPE ,C , 0.000E+00, 1.000E+01) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The contour plot for C, and those for B and A which follow, confirm that substances with high Prandtl/Schmidt numbers diffuse less fast than those with low ones.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV CONTOUR PLOT OF B ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV CONTOUR PLOT OF A ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

. Changing the print-out of "spot" values and residuals *******************************************************

>>> It was promised above that the plots of spot-values and residual sums would be modified in appearance. The first modification involves editing the instruction stack for case 244-248. An L57 command followed by an LC command reveals that the author of the case set NPLT to 1:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV L57 57 NYPRIN=2;NZPRIN=5;NPLT=1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Use of the command R56 allows the line to be modified to:

NYPRIN=2;NZPRIN=5

Reinterpretation of the instruction stack causes NPLT to assume its default value of -1, which is quickly ascertained by typing NPLT:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV NPLT = -1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> Execution of an EARTH run and analysis of the RESULT file shows that the plots for spot values and residuals have indeed changed. The default setting for NPLT gives rather infrequent values in the plots for spot values and residuals:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV SPOT VALUES VS. SWEEP (/ITHYD IF PARAB) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV RESIDUALS VS. SWEEP (/ITHYD IF PARAB) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The author of the Q1 file probably made a wise decision in his selection of the original value for NPLT.

>>> NPLT will now be reset to 1 for the next run, however attention will be focussed on the last 10 sweeps in the solution sequence by resetting the variable IPLTF, which is the first sweep number for which plots will be produced. IPLTF, formerly at its default value of 1, will now be set to 11, so that the spot-values and residual sums will be printed only for the last ten sweeps.

>>> The opportunity will be taken to exhibit two further print-out controls, namely ITABL and ORSIZ. These will be set to 3 and 0.4 respectively. The first causes tables of numbers to be printed in addition to the plots; and the second doubles the vertical scale of the plots.

The "help" facility should be consulted for further information about these and other GROUP 23 controls.

The relevant part of the RESULT file thereupon becomes:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV SPOT VALUES VS. SWEEP (/ITHYD IF PARAB) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV 1.00 P....+....+....+.B..+.B..+..H.+..A.+...A+...C+....C ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> It can now be seen that changes are still taking place in the spot values during the last ten sweeps; but they are small.

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV TABULATION OF ABSCISSA AND ORDINATES... ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The table and the plot confirm the generally-downward trend of the residuals.

>>> It should be mentioned that the printing and/or tabulation of spot-values and/or residuals can be controlled, variable-by- variable, by means of the last two arguments of the OUTPUT command. This is explained, along with other matters, in the "help" entry for OUTPUT, which is:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV ***** OUTPUT -------------------------------------- OUTPUT ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. Changing the print-out to the screen ***************************************

>>> The frequency, in terms of number of sweeps, with which the imbalances in the equations are transmitted to the VDU, is controlled by the value of the variable TSTSWP, for which the "help" file entry is:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV ***** TSTSWP ------------------------------------- TSTSWP ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> Print-out for a particular variable can be suppressed altogether by the setting of its RESREF to 0.0. Thus, if TSTSWP is set equal to 5 and RESREF(P1) is set equal to 0.0, the first print- out of imbalances to reach the screen is:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV TIME STEP = 1 SWEEP = 5 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This should be compared with the screen output which would have been obtained without these settings of RESREF and TSTSWP:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV TIME STEP = 1 SWEEP = 1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> As indicated by the "help" entry for OUTPUT, reproduced at the end of the previous section, the residuals print-out can also be suppressed for a particular variable by entering N as the fifth argument (i.e. the fourth yes-or-no slot) of the OUTPUT command. It is indeed better to do this than to set RESREF equal to zero; for it allows RESREF still to enter into the decision about when iterations or sweeps should be terminated.

**********************************************************

.. The use of RESTRT or AUTOPS ******************************

>>> Because it was desired to change the print-out relating to the whole run, the changes discussed in sections 2 and 3 necessarily involved repeating the run. This was not troublesome, because the execution time was so small.

When the print-out requirements relate only to final values, however, there is no necessity to repeat the whole calculation; instead one can simply make either a "restart" or an "autopsy" run, merely by changing the print-out control settings in the Q1 file.

>>> Restarts are effected by setting RESTRT(ALL) and LSWEEP=2 in the Q1 file. When EARTH execution starts, the message on the VDU screen (on the presumption that the last-mentioned TSTSWP and RESREF(P1) changes have been undone) is:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV GROUND STATION IS GROUND.FTN 11.10.86 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> Thus, one further sweep has been performed, starting from where the previous run left off (so that the residuals remain small). This was possible because the PIL variable SAVE equalled T (its default value) in the previous run, so that the fields stored on PHIDA could be picked up.

>>> Restarts are mainly useful when an exploratory calculation is being carried out, for which the PHOENICS user is certain at the start neither of the total number of print-outs that he will require nor of such other settings as numbers of sweeps and iterations, and values of relaxation parameters.

>>> However, if it is only the print-out about which he is uncertain, he can make use of the special kind of restart known as an "autopsy" run. This is effected by the Q1 command:

AUTOPS=T;RESTRT(ALL)

as the "help" entry for AUTOPS explains:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV ***** AUTOPS ---------------------------------------- AUTOPS ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> When EARTH is again executed, the message to the screen is now:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV INITIAL FIELDS READ FROM PHIDA ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

which differs in that all the residuals are reported as zero, because they have not in fact been calculated. The reason is that, in an AUTOPS run, only the print-out sequences are passed through: no adjustments to dependent variables are made at all.

>>> The RESULT file which EARTH prints looks very similar to one in which calculations were made; but the fact that an autopsy run is in question is indicated by the line, just below the grid-coordinate print-out:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV --- AUTOPSY OF SAVED FIELDS BEGINS --- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Moreover, the spot-value and residuals print-out is totally absent, for obvious reasons.

In the following sections, all the changes to print-out to be shown have been made by use of the AUTOPS facility.

.. Changing the print-out of "field" values *******************************************

>>> As mentioned above, the settings of IYPRF, IYPRL, IZPRF and IZPRL restricted the print-out of field values exhibited in section 1 above. The settings can be changed, if it is desired, in an AUTOPS run.

For example, if the PHOENICS user is interested only in the layer close to the wall, he might set:

IYPRF=NY-1;IYPRL=NY;IZPRF=1;IZPRL=NZ

>>> If, moreover, he were concerned to print values at only one- third of the z-direction locations, he would set:

NZPRIN=3

The resulting print-out for P1 in the autopsy run would be:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV FIELD VALUES OF P1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> The field print-out seen so far has arranged the numbers in 5 columns. This arrangement may be changed by setting the variable NUMCLS to a different value. Thus NUMCLS=3 would lead to:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV IY= 20 1.162E-01 1.098E-01 -2.850E-02 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The largest permissible value of NUMCLS is 10.

**********************************************************

.. Changing the print-out of "profiles" ***************************************

>>> Only one profile plot is shown in the output of section 1. Suppose now that the PHOENICS user wishes to examine the way in which variables change their values along the axis; then an AUTOPS run could be conducted for which the following instructions had been included:

PATCH(AXIS,PROFIL,1,1,1,1,1,NZ,1,1);PLOT(AXIS,W1,0.0,0.0) PLOT(AXIS,P1,0.0,0.0);PLOT(AXIS,A,0.0,1.0) PLOT(AXIS,B,0.0,1.0);PLOT(AXIS,C,0.0,1.0) ORSIZ=0.4

Here the 0.0's in the third and fourth argument slot of PLOT allow the plotting procedure to choose it own vertical scale; but, where 0.0 and 1.0 appear, these values are enforced as the upper and lower limits of the variables in question. The print-out therefore becomes:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PATCH(AXIS ,PROFIL, 1, 1, 1, 1, 1, 20, 1, 1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> From this plot one can see the steep fall and shallower rise of pressure P1, the rise of axial velocity towards a maximum just down- stream of the orifice, followed by a fall, the rapid rise of concentration of the strongly-diffusing scalar B and the correspond- ingly slower rises of the concentrations of A and C.

The slow rate of diffusion of C results in very little information being provided about its axial concentration profile. This would be better shown if the self-scaling settings were made, thus:

PATCH(AXIS,PROFIL,1,1,1,1,1,NZ,1,1);PLOT(AXIS,A,0.0,0.0) PLOT(AXIS,B,0.0,0.0);PLOT(AXIS,C,0.0,0.0)

The resulting autopsy print-out is:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PLOT(AXIS ,C , 0.000E+00, 0.000E+00) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

From this it is possible to detect what would otherwise have escaped notice, namely that the axial profile of concentrations A and C are so similar that the C's are almost all over-written by the A's.

>>> Further inspection of the graphs reveals something interesting about the right-hand end: how is it that low values of concentration arise there? An autopsy run providing profiles for the IZ=NZ slab is informative, as follows:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PATCH(IZEQNZ ,PROFIL, 1, 1, 1, 20, 20, 20, 1, 1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> What this shows is that there is a reduction of pressure at the axis, caused by the rotation; and, tiny though this is, it must suffice to cause a small inflow. Since nothing has been said about the concentration of A, B, and C in any material flowing in from the high-z end of the duct, these concentrations have been taken as zero. This explains the low values of concentration near the axis.

>>> This observation is discussed further in the tutorial concerned with boundary conditions. Here it will simply be remarked that the line-printer profile plots, despite their low resolution, can still bring to attention features that might well be missed if only tables of numbers were being inspected.

>>> The profile-plot facility has more features than there is space to describe here. To learn about all of them, the reader should consult the "help" file. One feature is however important enough to deserve attention now; it is the variable IPROF, which is defaulted to 1. An example of its use is the following:

PATCH(NEARWALL,PROFIL,1,1,NY,NY,1,NZ,1,1) PLOT(NEARWALL,B,0.0,2.0);IPROF=0

This leads to the print-out:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PATCH(NEARWALL,PROFIL, 1, 1, 20, 20, 1, 20, 1, 1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> In contrast to the previously-seen profiles, the value of the variable is here plotted horizontally, while the geometrical- coordinate index runs vertically downward. In the latter connexion it should be noted that every third z-location is represented, which implies that the previously-set value of NZPRIN has not been cancelled.

It will also be noticed that the values of the variable are tabulated, a feature that is frequently useful.

>>> IPROF can take other values, namely 2 and 3. If IPROF=2, tables of all the values for the same PATCH are printed side by side. Thus, the above instructions for the patch named AXIS, would have yielded, for IPROF=2:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PATCH(AXIS ,PROFIL, 1, 1, 1, 1, 1, 20, 1, 1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> Here, it will observed, NZPRIN does not operate so as to "thin out" the tabulation.

>>> IPROF=3 causes both tables and profiles to be printed, the profiles being in the IPROF=1 format; but there is no need to illustrate this.

**********************************************************

.. Changing the print-out of "contours" ***************************************

>>> Since tables can be printed out in a selective manner by way of PATCH (with PROFIL as the second argument) and PLOT, it may be recognised that the field print-out feature will not always be needed. This recognition is given added force by the fact that PATCHes with CONTUR as the second argument can also give rise to tabular print-out, either in addition to or as a substitute for the contour-plots themselves.

The relevant "help" entry on this topic, which is elicited by typing CONTUR, is:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV If the name of the PATCH starts with the letters TAB, the ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>>> Consider, for example, the instructions:

PATCH(TBO1,CONTUR,1,1,9,NY,4,8,1,1) PLOT(TBO1,P1,0.0,20.0)

for which the autopsy print-out is:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PATCH(TBO1 ,CONTUR, 1, 1, 9, 20, 4, 8, 1, 1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

It will be recognised that this table contains the same information as appeared under FIELD VALUES OF P1, in section 1; only the arrangement on the page is different. The ability of the user to localise the region for which he wants to have field values tabulated renders the TAB and TBO options extremely useful.

Once again, the reader is advised to turn to "help" for full information about the contour-plotting facilities of PHOENICS. The last feature which will be mentioned here is that the fourth argument of the PLOT command dictates how many contour bands will be plotted.

>>> Consider, for example, a contour plot which is elicited by the command:

PATCH(PIPE,CONTUR,1,1,1,20,1,20,1,1) PLOT(PIPE,H1,0.0,30);NCOLCO=30;NROWCO=30

which differs from that in library case 248 in calling for 30 rather than 10 bands, and also (so as to illustrate other options) in making the plot width 30 columns rather than 45 and the plot height 30 print lines rather than 20. The autopsy run then yields:

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PATCH(PIPE ,CONTUR, 1, 1, 1, 20, 1, 20, 1, 1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

As compared with the 10-band version of this plot in section 1 above, this 30-band version may be considered much more informative; and the changed proportions give a reminder of which is the length dimension and which is the radial.

**********************************************************

.. Other output facilities **************************

>>> Finally it should it emphasised that this lecture has concerned itself with only the most easily accessible of the output options of PHOENICS.

Quite apart from the further details concerning which the user has been advised to turn to "help", there are two large topics which have been entirely neglected.

>>> The first is the use of the true graphical-output facilities of PHOENICS, namely those associated with the VIEW command which can be employed by the interactive-satellite user, and with the separate output-display program PHOTON.

>>> The second is the use of the facilities provided in the sub- routine GROUND, both for eliciting information about other coefficients, sources and quantities which may be of interest, and for printing it out in various ways.