WORKSHOP - Flow Simulation within a pipe.

The following instructions will allow the user to set up and run the simulation of gas in a pipe using VR. The domain is treated as a solid, and the pipe is 'carved' out by making the pipe sections from a fluid material.

The flow is three-dimensional and its geometry is shown below:

 

Accessing PHOENICS-VR.

From the system level:

To enter the PHOENICS-VR environment, type 'pc'.

In PHOENICS-VR environment,

Start with an ‘empty’ case - click on 'File' then on 'Reset Default data’, then click on ‘OK’ to confirm the resetting.

To enter VR Editor:

This is the default mode of operation.

 

Within VR Editor.

Set the domain size, activate solution of variables and set the domain material:

Click on 'Menu' and then on 'Geometry'.

Change the X-domain Size to 1.5 m.

Change the Y-domain size to 0.3 m.

Change the Z-domain size to 2.0 m.

 

Click on 'Models'.

Set the 'solution for velocities and pressure' ON.

Select the LVEL Turbulence model in 'Turbulence Models'.

Click on 'Top menu' then on 'OK'.

If the graphics image still shows the default domain, right-click on 'reset view parameters' to update the view.

 

Create the solid domain block:

Click on 'Obj'.

Change name to DOMAIN.

Set POSITION and SIZE of object as:

Xpos: 0.0 Xsize: 1.5

Ypos: 0.0 Ysize: 0.3

Zpos: 0.0 Zsize: 2.0

Define Type: Blockage (default).

Click on 'Attributes', click on 'Other materials', 'Solids' and set the material as 'No111, Steel'.

Click on 'OK' to exit the attributes menu, and click on 'OK' to close the Object Dialogue box.

The object is selected, click on the 'Hide' button (below the 'Axis toggle') to hide it.

 

Create the first horizontal pipe segment:

Click on 'Obj'.

Change name to PIPE-1.

Set POSITION and SIZE of object as:

Xpos: 0.0 Xsize: 0.3

Ypos: 0.0 Ysize: 0.3

Zpos: 0.0 Zsize: 0.3

In 'Geometry', select SHAPES/CYLINDER.DAT.

Define Type: Blockage (default).

Click on 'Attributes', click on 'Other materials', 'Gases' and set the material as 'air at 20 deg, 1 atm'.

Click on 'OK' to exit the attributes menu, and click on 'OK' to close the Object Dialogue box.

The object is selected, click on the 'Rotate object up' button (below the 'Axis toggle') to give it the right orientation: the axis of the cylinder is in X-direction.

 

Create the second horizontal pipe section by duplication from PIPE-1:

Click on 'Duplicate object or group'.

Click on 'X position up' until the copy object has moved as far as possible in X (Xpos=1.2)

Click on 'Z position up' until the copy obect has moved as far as possible in Z (Zpos=1.7)

Click on the copy object and change name to PIPE-2.

 

Create the vertical pipe section:

Click on 'Obj'.

Change name to PIPE-3.

Set POSITION and SIZE of object as:

Xpos: 0.6 Xsize: 0.3

Ypos: 0.0 Ysize: 0.3

Zpos: 0.6 Zsize: 0.8

In 'Geometry', select SHAPES/CYLINDER.DAT.

Define Type: Blockage (default).

Click on 'Attributes', then on 'Other materials', 'Gases' and select the material as 'air at 20 deg, 1 atm'.

Click on 'OK' to exit the attributes menu, and click on 'OK' to close the Object Dialogue box.

The cylinder already has its axis in the Z-direction as desired.

 

Create the lower pipe bend:

Click on 'Obj'.

Change name to BPIPE-1.

Set POSITION and SIZE of object as:

Xpos: 0.3 Xsize: 0.6

Ypos: 0.0 Ysize: 0.3

Zpos: 0.0 Zsize: 0.6

In 'Geometry', select SHAPES/PIPEBEND.DAT.

Define Type: Blockage (default).

Click on 'Attributes', then on 'Other materials', 'Gases' and select the material as 'air at 20 deg, 1 atm'.

Click on 'OK' to exit the Attributes menu, and click on 'OK' to close the Object Dialogue box.

Rotate the pipe to give it the right direction (clip art rotation 9/24).

 

Create the second pipe bend by duplication from BPIPE-1:

Click on 'Duplicate object or group'.

Click on the copy object (at 0,0,0)

Change name to BPIPE-2.

Set POSITION of object as:

Xpos: 0.6

Ypos: 0.0

Zpos: 1.4

Rotate the pipe to give it the right direction (clip art rotation 3/24).

 

Create the fluid inlet:

Click on 'New Object'.

Change name to INLET.

Set POSITION and SIZE of object as:

Xpos: 0.0 Xsize: 0.0

Ypos: 0.0 Ysize: 0.3

Zpos: 0.0 Zsize: 0.3

In 'Geometry', select SHAPES/CYLINDER.DAT.

Click on 'Rotation' and toggle clip art rotation to 24/24

Define Type: Inlet.

Click on Attributes to define the inlet conditions.

Set the velocity of the inflow in X-direction at 1.0 m/s.

Click on Inlet density is 'Domain Fluid' to toggle it to 'user-set', and set the density to 1.189 kg/m**3, i.e. that of air.

Click on 'OK' to close the Attributes menu, and on 'OK' in the Object Dialogue Box.

 

Create the fluid outlet:

Click on 'New Object'.

Change name to OUTLET.

Set POSITION and SIZE of object as:

Xpos: 1.5 Xsize: 0.0

Ypos: 0.0 Ysize: 0.3

Zpos: 1.7 Zsize: 0.3

In 'Geometry', select SHAPES/CYLINDER.DAT.

Click on 'Rotation' and toggle clip art rotation to 3/3.

Define Type: outlet.

Leave the default values in the Attributes Dialogue box.

Click on 'OK'.

 

Set the grid and remaining solution control parameters:

Click on 'Main Menu' and then on 'Geometry'.

Set grid dimension

in X-direction at 20 cells,

in Y-direction at 5 cell,

in Z-direction at 30 cells.

 

Click on 'OUTPUT'.

Place the probe in the middle of the vertical pipe section by setting

XMON to 0.75,

YMON to 0.15,

ZMON to 1.5.

 

Click on 'Numerics'.

Set the number of iterations to 100.

Click on 'Relaxation control' and set DTFALS (false time step) for U1, V1 and W1 to 10.

Click on 'Previous panel' to return to 'Numerics'.

 

Click on 'Top menu' to return to the top menu.

Click on 'OK' to exit the Main Menu.

 

Running the Solver.

In the PHOENICS-VR environment, click on 'Run', then 'Earth' and on 'Yes' when prompted to save data to files.

 

Using the VR Viewer.

In the PHOENICS-VR environment, click on the 'VR Viewer' button and view the velocity vectors, contours and iso-surfaces.

 

Saving the results.

In the PHOENICS-VR environment, click on 'Save as a case', make a new folder called 'PIPE' (e.g.) and save as 'CASE1' (e.g.)