Particle tracking with StarCD

Generating a mesh
Boundary conditions
Particle tracking

Generating a mesh (2D)

To do the mesh, you just have to follow the guide.
Be careful to choose shell for the cell type.
Then type the dimension of your domain, and the number of cells.
At last, click the generate 3D mesh from 2D mesh. Now, you have the mesh back

Boundary conditions

The next step is to define the boundary regions.
All you have to do is always to follow the guide.
You select a line, say if it is inlet, outlet, wall... and click the cells you want to be defined. For this step, the zoom is very usefull.

An important thing to know, is that every none defined zone is automatically put by StarCD in the 0 zone and defined as what is written (wall here). If you try to click, you will not be able to make it appear.
Now, if you want to define a geometry as our, with holes in it, here is the magic sequence of instruction we have been looking for during hours:
The first one will enable you to select only somme cells,
the second one draw them
the third one erase them.

cset news gran xmin xmax ymin ymax
cdel cset

For instance, our first element has been erased with:
cset news gran 0.005 0.02 0.06 0.064

Once you have deleted all the zones you want to, this is what you can get.       back

Particle tracking

Once you have made your geometry, you launch the calculation (it is simpl compared to the difficulty of meshing!)
And then you can import the result and draw the tracks.

To that end go in the load data window and choose velocity vectors and density scalar. Then choose the  post processing option and partivle tracking.
Here is what you get    The second picture shows the nodes we have selected when clicking add locations to list

Now, you have defined the initial positions of the particles. You can init the calculation. Click the right upper icon option.

You can see all the vertices that you have selected.

An important thing to do is to click the scan-->all cells so that StarCD dtermines which cells are concerned. You will see the number of the cell appear in the right of the vertice number, instead of a 0.

At last, choose a diameter and a density ( you are not obliged to!), in the white zones under the array. Then click modify for the computer to take the changes into account.

Now, you can get your tracks by clicking Generate tracks and then Plot particle track.

If you want a small animatiom, choose segment instead of continous in the display option icon.

Here is the result.

back EXIT