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Description of the PHOENICS-Direct facility:
Multirun

by Alexey Ginevsky, Elena Pankova and Brian Spalding, May 2013

Contents

  1. The purpose of the Multirun facility
  2. Getting to know the Multirun facility
  3. Concluding remarks

1. The purpose of the Multirun facility

A useful utility of the PHOENICS-Direct package is its Multirun facility. It has been created to enable a user:

2. Getting to know the Multirun facility

2.1 User interface

The Multirun utility of the PHOENICS-Direct software can be accessed by clicking on the Multirun button of the PHOENICS-Direct main screen.

Having done so, the user opens the Multirun screen looking as follows.

The Multirun screen displays the following components:

Toolbar The toolbar presents buttons for common commands, such as:

- 'Add parameter' button - to open any group in search of a variable to be changed in the Multirun calculation;

- 'Open file with settings' button - to open files with previously saved settings for the concrete multirun calculation;

- 'Save settings' button - for saving concrete settings to be used in future multirun calculations;

- 'Run' button - to launch a Multirun calculation;

- 'Terminate calculations' button - to stop the calculation in progress if for any reason it is no longer needed;

- 'Open CSV-file' button - to open the Multirun plotting screen and create a csv-file.

Saving Files area The area on the left contains the list of files that, when selected, can be saved in course of this multirun. There is also the 'File Prefix' box wherein the name of the multirun session is to be entered should a user wish to save separately the earlier chosen files for each concrete variant of the multirun session.
The 'Collect inforout' box in the bottom left corner is selected by default; otherwise the results of the Multiruns session might be lost.
If the results to be obtained are to be represented graphically, i.e. in the form of plotted curves, the 'Plot from inforout' box should be also selected.

Changing Parameters area The 'Changing Parameters' area on the right will contain the names of variables to be changed in the calculation and their concrete values.

2.2 Introducing changing patrameters for multiruns

We remind that all parameters apart from those to be changed in the course of multiruns are transferred from the basic window ('Inspect or modify Input Data' tab) of the PHOENICS-Direct package. The following examples pertain to the TubeFlow SimScene; but the facilities described are available for all SimScenes.
  1. Click the 'Add parameter' button to be able to open any group from the list


    containing a parameter to be changed.
  2. Having decided upon e.g. the tube inner diameter from the Geometry group, a user will have to choose this parameter from the 'Changing Parameters' box and then type the necessary values of this parameter into the empty box to the right, separating one value from another by a semicolon.

    Some users might wish to introduce another to-be-varied parameter from some other group. In this case, they may click the 'Add Parameter' button again, choose another group from the list, choose the parameter in question from the 'Changing Parameters' list and set its values in a new box on the right.

    Users may add as many parameters as they wish. It should be noted, however, that computer time will be increased accordingly, as during the Multiruns calculations only one parameter is changed at a time. What follows is a set of parameters chosen for the multirun, Reynolds number from the Boundary conditions group and Prandtl number - from the Material properties group.

  3. Should a user wish to represent the obtained results graphically by means of curves, he should put a check-mark into the 'Plot from inforout' box, which is not selected by default.

    The results will not be plotted if a user has not selected the box in question.

2.3 Saving settings and making multiruns

It may be convenient to save the created list of selected parameters into a separate xml-file if one has any need to use these same parameters for future calculations. To do so, the 'Save settings' button should be pressed and the name of the file should be typed in a standard dialog window. To use these very settings in future calculations, the user will only have to open this xml-file from the multirun folder clicking on the 'Open file with settings' button from the Multirun window toolbar, instead of typing them manually into the corresponding boxes.

Finally, to carry out the multirun click on the 'Run' button.

2.4 Drawing plots

If the user has selected the earlier-mentioned 'Plot from inforout' box, upon termination of the Multirun session the following window will open wherein the necessary plotting parameters should be specified.

  1. In the 'File Name' box type the name of the csv-file to be created from the inforout file that will contain the data for results plotting, e.g. t1.
  2. From the 'Abscissa' box select a variable to be used as the plot abscissa, e.g. REYNOLDS_NO.
  3. In the ordinates section choose variables that will be the ordinate or ordinates if several curves will be plotted, e.g. NUSSELT_NO.
  4. In the 'Split by parameter' box choose PRANDTL_NO to draw the Nu(Re) curves for different Prandtl numbers. The screen should look similar to what follows.

  5. To save the t1.csv file click on the 'Save File' button below.
  6. The message confirming that the t1.csv file was created will appear. Click on the 'OK' button.
    If it is desired to make other plots in different coordinate systems, all that is needed is to create new csv-files and save them in the described manner. However, this can be done later so long as the current inforout file resides in the Multirun folder.
  7. In the end click on the 'Close' button to close the Multirun plotting window. There will be another message asking whether the plot for the latest csv-file should be drawn. Press 'OK' to confirm this.
    The following image will then appear.


    Three curves Nu=f(Re) for three various values of the Prandtl number are plotted.
    You can change the settings for this plot clicking on the button and opening the window that follows.


    This window allows the logarithmic scale to be used for the abscissa and ordinate axes, introduction of new ranges for the axes as well as new variables names to appear in the plot upon making these necessary changes and clicking on the 'OK' button.
    The image that follows shows the previous plot redrawn in logarithmic axes, with changed value ranges and names for the variables applied.


  8. If you want to save this image for later use, click on the ’Save’ button , type its name and location, and specify the graphic format (jpeg, bmp, wmf, gif) from the pull-down list of the 'Save as' box. However, once the original csv-file has been saved, the graphic file can always be obtained from it.
  9. The Multirun window still remains open and it is a good opportunity to save the parameter set being used for future calculations if not done earlier (as shown in section 2.3).
  10. Close the Multirun window to return to the PHOENICS-Direct main one.

2.5 Using inforout file and drawing plots without calculation

It is now possible to use the old inforout file for creating new csv-files and drawing new plots without immediate calculation. Since the Multirun calculation has been made, the inforout file created and stored in the multirun folder, one can use it any time to draw new plots from new csv-files.

The sequence of actions is as follows.

  1. Open the PHOENICS-Direct main window.
  2. Get to the Multirun window.
  3. Click the button to open already familiar Multirun plotting screen to create a new csv-file.
  4. Repeat the steps 1-6 of the previous subsection and close the Multirun window.
  5. In the PHOENICS-Direct main window click on the 'Open csv-file' button  , browse to in the /phoenics/d_sapps/TubeFlow/multirun folder, wherein the results of the multiruns are saved by default, and choose the file in question by the name of the corresponding csv-file. It must be mentioned here that these files contain tables that can be read by MS Excel which is definitely a more powerful editor for graphical representation of table data.

3. Concluding remarks

Thus the Multirun facility of the PHOENICS-Direct package enables its users
  1. to carry out multiple runs of the Solver module without further intervention,
  2. to vary several parameters in one multirun calculation,
  3. to undertake thus parametric studies of a required variable,
  4. to examine the results by examination of both graphical displays and printed documents,
  5. to draw the required plots at a later time chosen by the user,
in a very simple and intelligible way.