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TUTORIAL- Simulation of a Labyrinth Flow.

This tutorial shows how to set up and run the simulation of steady turbulent flow of air with heat exchange.

The geometry is 2-dimensional, of (y-direction) depth 1.0m, with the other dimensions shown in the figure below:

wherein:

Preliminary remarks

  1. The tutorial must therefore explain how to:
  2. In addition to physically-meaningful data of the above kind, all CFD codes, and therefore PHOENICS also, require non-physical inputs such as:
  3. The non-physical settings suggested below are such as to make the calculations rapid rather than accurate.
  4. Other tutorials will be provided which will enable you to explore the influences of the settings on accuracy and speed of calculation.

Starting the tutorial

First close any windows which are already running PHOENICS modules.
Then activate the PHOENICS Satellite module, in its VR-Editor mode, by either:

  1. clicking on the PHOENICS VR icon on the desktop; or
  2. entering the Run Modules panel of the PHOENICS Commander, and then clicking the VRE button; or
  3. typing 'vre' at the Command prompt.

Your working directory, i.e. the folder in which will appear all the files which the tutorial creates, will be, according to the method which you have used:

  1. /PHOENICS/d_priv1 [You can change this, if you wish, by clicking the 'options button' at the top of the satellite panel; or
  2. that which appears after: set globdata(cwd) in the file: /PHOENICS/d_pc/userpref/pcprefs . [You can change this, if you wish, by clicking the 'Customise' button of the PHOENICS Commander Top Page]; or
  3. that of the prompt itself.

In PHOENICS-VR Editor

Set the domain size

Select the working fluid

Indicate for which variables solution is required

Re-sizing the domain

The domain no longer fits the screen; to resize, click on the pull-down arrow next to the 'R' icon on the toolbar; then 'Fit to window'.

reset1.gif (3045 bytes)

Introduce the required objects

  1. Introduce the H-BLOCK object

  2. Introduce the L-BLOCK object

  3. Introduce the WALL-E object

  4. Introduce the WALL-W object

  5. Introduce the IN-PLATE object

  6. Introduce the IN-BLOCK object

  7. Introduce the INLET object

  8. Introduce the OUTLET object

Inspect the 'default' grid

The PHOENICS satellite sets a computational grid which has sufficient lines at least to co-incide with the extremities of all the objects which have been introduced, with some additional lines in-between.

This is known as the 'default' grid. It can be displayed by pressing the 'Mesh toggle' button, which in the present case should generate a picture such as the following.

wk1grid.gif (9803 bytes)

The remaining solution-control parameters

In later tutorials, you will be invited to click on 'Menu' and then on 'Numerics', in order to inspect and modify other solution-control parameters. However, the defaults which have been set will suffice for the present purposes.

Setting the Probe Location

Running the Solver

You are now ready to perform the simulation by activating the PHOENICS solver module (known as 'Earth').

In order to do so, click on 'Run', 'Solver'(Earth), and click on 'OK' to confirm.

You will then see, in quick succession, indications on the screen of:

Click the 'END' button to terminate the calculation and to return to the VR Environment.

You are now able to launch the VR Viewer, in order to inspect the results of your calculation.

Using the VR Viewer.

Click on 'Run', 'Post processor', then GUI Post processor (VR Viewer) . Click 'OK' on the file names dialog to accept the default files.