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-   -   Modeling CSTR (http://www.cfd-online.com/Forums/ansys/80764-modeling-cstr.html)

vitormhenrique October 5, 2010 21:18

Modeling CSTR
 
Hello,

I trying to model a CSTR in ANSYS (CFX or FLUENT) but i'm having doubt to build the geometry of the problem.

Someone has a tutorial of this kind of problem? I do not know how to insert the initial conditions for the impeller or if you need to separate it somehow from the rest of the geometry.

Thank you for your consideration,

Vitor Henrique

Pallen October 7, 2010 21:23

There is a tutorial in CFX for the multiphase modelling which involves a CSTR model.
Basically you need to make 2 geometries, one for the main tank with baffles and one for the impeller region with a surrounding mesh. Then put them together. You can add in hubshafts and the like once you understand what's going on.

But I highly recommend doing the tutorial in CFX first.

vitormhenrique October 8, 2010 09:03

Hello,

I've had a look at this tutorial, but i have doubt in the geometry creation, and the mesh generation for the impeller, and for this tutorial, the geometry was already established.

Do you know any tutorial with geometri creation, for moving parts?

Tanks,

Vitor Henrique

PAMPS September 25, 2012 10:36

geometry creation of impeller for CFX
 
Quote:

Originally Posted by vitormhenrique (Post 278444)
Hello,

I've had a look at this tutorial, but i have doubt in the geometry creation, and the mesh generation for the impeller, and for this tutorial, the geometry was already established.

Do you know any tutorial with geometri creation, for moving parts?

Tanks,

Vitor Henrique

Hi Vitor Did you manage to solve your problem. I'm having the same problem now.
There is anywhere explained how to make the correct geometry of an impeller with its rotating domain.

PAMPS

Pallen September 25, 2012 19:21

Sorry Vitor for not replying I did not realise you had followed up all that time ago. Since you are probably well passed this question I'll reply to you PAMPS.

The creation of the geometry is easiest in a 3D modelling program which you will have to learn to use. If you do the tutorials for whichever 3D modelling program you should be able to learn how to make an impeller quite easily. You don't need to do a tute specifically related to an impeller as you'll get the basic tools you need and go from there. Also, it is not something that is easy to explain in words, you'll need to just practise it.

My basic process involves making the impeller geometry, then making a cylindrical domain. Then I boolean subtract the impeller geometry from the cylinder to leave the cfd volume. The same as pretty much all cfd volumes.

Good luck.

Pallen

PAMPS September 26, 2012 11:34

Importing/Creating Impeller Geometry in DM
 
Hi Pallen,

Thank you for the answer. I am studying ANSYS DM. I am struggling with the first steps of drawing the impeller surface which cannot be done by the standard process of 2D sketch to 3D surface.

1. As I have the impeller sections in ACAD, and in script files (sections and periphery line). I do not have a surface.

Is the best aproach to use text files to import all the points I have as "construction points" into ANSYS DM and then loft a surface through them?
or is there another possibility?

2. After having the impeller geometry I have to create the rotating (the cylinder) domain with the same pitch and shape at periodic domain interfaces (as do not want to model the 360 but only one blade (120).
Is that possible to create the periodic interfaces with standard Design Modeler or do I have to use DM withTurboEditor?

3. I have studied several tutorials and some of them have a "stagefluidzone" behind the impeller. Do I need this feature?, since at the end of the day I need to have a good estimate of the POWER and TORQUE delivered/absorbed by the ensemble impeller/shaft.


Thank you for some guidance.

PAMPS November 11, 2012 18:20

Modeling an impeller + shaft geometry
 
1 Attachment(s)
Hi All,

Since my last questions I managed to model the impeller using construction points, splines and the loft function.
Now the following steps are not working:

1. The impeller is a surface body while the shaft is a solid body. When I try boolean operations, in order to match perfectly the impeller with the hub (by subtracting excess of material which is inside the hub), it doesn't work.

What should I do?

2. When I try to mesh the geometry in ANSYS meshing tool, it doesn't mesh the impeller.
Even when I manage to mesh de impeller blade using ICEM CFD, then CFX Pre doesn't recognize it and doesn't import it.

What should I do?


Other questions that I still do not have a clue:

3. After having the impeller geometry I have to create the rotating (the cylinder created by function "Enclosure") domain with the same pitch and shape at periodic domain interfaces (as do not want to model the 360 but only one blade (120).
Is that possible to create the periodic interfaces with standard Design Modeler or do I have to use DM withTurboEditor?

4. I have studied several tutorials and some of them have a "stagefluidzone" behind the impeller. Do I need this feature?, since at the end of the day I need to have a good estimate of the POWER and TORQUE delivered/absorbed by the ensemble impeller/shaft.


Thank you for some guidance even if only in one of these questions.


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