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-   -   [ANSYS Meshing] Inlet Pump - Creation of sweepable bodies (http://www.cfd-online.com/Forums/ansys-meshing/112233-inlet-pump-creation-sweepable-bodies.html)

DarkRudy January 24, 2013 07:06

Inlet Pump - Creation of sweepable bodies
 
2 Attachment(s)
Hello,

my name is Martin and I'm new to this forum. I've started working with Ansys Workbench a couple of weeks ago und now I'm having some problems with a small project. I hope you can help me with that.
I would like to simulate a flow at the entrance of a pump. I have designed a simplified model of the flow channel with the ansys design-modeler. This one you can see in the picture, which i have attached.

1. The fluid enters at the bottom of the annular chanal.
2. ... then it flows trough the four inclined, small tubes to the 3rd section of the model.
3. The fluid leaves the model at the top area of the cylinder in the middle.
4. I have cut the whole system along the longitudinal axis.

When I open the system to create the mesh, the programm shows me that every body is sweepable. But for the simulation I want to define only "one entry" and "one exit" ( in addition to that the nodes and edges on the contact surfaces should be identical between the individual bodies), so I put the bodies together to one assembly. Now only the small connecting channels are sweepable. Is there a way to get this assembly sweepable? Or is the geometry too complex? How do I deal with this problem?
I have read that the sweep-method is advantageous for such flow simulations, but which alternative can I use, if this method can not be applied to the bodies? The mesh of the net should be very fine to examine the movement of particles or bubbles.

Mhh, I hope, I did not forget anything. Thank your very much for your help.

Kind Regards
Martin

flotus1 January 24, 2013 07:22

Remember to freeze the bodies before forming an assembly.

jrunsten January 24, 2013 09:25

The fact that you have formed a part from all your bodies creates imprints of the small tubes on the faces of the big ones:

http://i.imgur.com/J3FSxk4.png

If you explode the part it will be sweepable. You will end up with separate bodies with nodes not matching, so you will then need to set up interfaces between them.

http://i.imgur.com/MmDMBKc.png

DarkRudy January 25, 2013 14:33

...wow, thx for your help and the fast answers. Unfortunately I am only able to work on it at my university. So I will try it on monday and then I can give a feedback. Have a nice weekend!

DarkRudy January 28, 2013 08:55

Thank you for your help so far.
@ flotus1: I guess, that the DM automatically creates the frozen bodies, when I separate them with the function “slice”. In the tree outline all bodies are marked with that “icecube”-symbol. Nevertheless I have recreated the parts with the function “Add frozen”. But it doesn’t change the fact, that the created assembly is not sweepable.
@ jrunsten: What do you mean with setting up interfaces between them?:)

jrunsten January 28, 2013 08:58

I mean in the solver (Fluent, CFX etc), you need to set up interfaces between the bodies, since the mesh is not connected node by node. This also means that the inflation layers at these interfaces wont be continuos. Now I'm just talking about sweep meshing here, since that's what you asked about. You could also tet mesh the entire thing, or go into ICEM and create a nice hex mesh.


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