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papamichous October 22, 2014 04:46

cylindrical coordinate
 
Hi,:)
How can I use cylindrical coordinates in ANSYS CFX?

Thomas MADELEINE October 22, 2014 05:33

Hi,
your question is quite large...
When you have defined your axis you can access to the radius and theta variables.
See any tutorial in turbomachinery (tuto #14 for instance) to have an example.

papamichous October 22, 2014 09:02

Hi,
i want simulate this case of water flow through a porous media

Thomas MADELEINE October 22, 2014 10:30

So if you want to simulate without the standpipes you have a rotationnal symmetry.
So you can define only a part of the domain (1/6 => 60° for instance) and use the axis to define your symmetry. You will have a radius variable in CFX Pre.

In the case you want to keep your standpipes (it can affect the flow), you don't have any symmetry so you wille have to define the whole domain and I don't know how create an axis...
In this case I will probably use a very ugly method by create my own radius expression...
for instance if you axis is z:
Radius = sqrt((x-x0)²+(y-y0)²)
Theta = atan(y/x)*step(x)+(atan(y/x)+180)*step(-x)
or something equivalent

papamichous October 22, 2014 11:46

can you create the geometry for me for both?

Thomas MADELEINE October 23, 2014 04:18

Hi,
I am sorry but I can't create the geometry...
But I don't think it is really complex... you can create a cylinder a cut it into three pieces...
Then for the one with standpipe:
you add two small cylinders.
For the symmetric one:
you cut every thing by an angle of your choice (45° or 60° sounds correct to me)
Normally any 3D CAD software can handle it

papamichous October 23, 2014 09:33

how can I represent the shear stress between the fluid medium and the porous medium?


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