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soni_sth October 6, 2011 10:37

Mesh generation
 
Hi I am trying to make grid of a turbine which was modelled from blade modeler. I am using gridgen for that but I am not being able to refine the grids at the blades.I am making structured mesh.The cells get skewed and and when I make a mesh check on FLuent,it fails.So is Gridgen a proper tool for meshing a turbomachine?I have turbogrid now.But if it works on gridgen I wanted to do it on that.Can anyone please suggest me!!! I would really appreciate..Thanks!

Far October 6, 2011 12:42

Use TurboGrid, It is lot easier than working on Gridgen. As TG will do many tasks automatically, on the other hand in Gridgen you have to do every thing yourself. It is to be noted that Turbo-Machinery have curved geometry at hub and casing, which makes them very much difficult manually.

soni_sth October 6, 2011 15:00

Thanks for the reply Far.But I have iges file of the whole turbine.I went through the manual of turbogrid,it requires curve files.Are these curve files generated in Blademodeler?CAn I use my IGES file for turbogrid?

Far October 6, 2011 15:08

Use gridgen for this purpose. Put 200-300 nodes on the periphery of turbine. plance 5-6 nodes along span wise direction. make the domain on the blade surface. Now you will see the 5-6 airfoil with mesh on them, take these coordinates and past them in turbogrid file (profile). Similarly work on hub and shrould and past these coordinates in the respective files i.e hub.curve and shroud.curve

jchawner October 7, 2011 09:25

Hi Soni:

TurboGrid is a great program for meshing bladed geometries, especially those that come from Blade Modeler. After all, the two programs were designed to work together. Plus, I know the guy who wrote one of the original versions of TurboGrid.

However, I'd like to point out that Gridgen and Pointwise are very well suited for turbomachinery meshing which is why it's one of our largest markets. We have several people on staff with turbo experience so if you want to exchange ideas about meshing, don't hesitate to contact our tech support at support@pointwise.com.

Best Regards

soni_sth October 11, 2011 10:59

@Far:thanks for the reply Far.I dont have database for the curve passages.IS it possible to make it on gridgen or do I need to make it on blademodeler?Thanks

@John:Thanks John.I have contacted Wenny for this matter.

Far October 11, 2011 11:09

you can make the mesh in gridgen as well. If you have some script then It will be very easy to make mesh, other wise it is not as straight forward as making mesh for the 3-D wing. Same goes for the ICEM CFD. I should say it is a painful job of couple of weeks or so.

But if you have turbo grid, it has built-in function for generating high quality meshes for the rotating machinery in couple of minutes or so. For this you don't need to have the data base in the gridgen. If you have connectors/domains or data in the x,y,z format you can easily setup the turbogrid file.

Let me know if you need detailed help in going from one program to other.

soni_sth October 11, 2011 11:46

Thanks Far,

Can I send you the file in your mail.So it's easier for me to explain my question?

soni_sth October 11, 2011 12:30

Hi Far,
Can you please take a look on the attached file.

Far October 11, 2011 13:33

sure. i m sending my email id in PM

Far October 11, 2011 13:42

@John Chawner: If you can send him the TCL/Tk script for turbo machinery, then It would be much easier for him to make the good quality mesh in couple of minutes I guess? I know Gridgen is very very good mesh generation software for CFD and FEA.

@soni_sth : If you have the PointWise license and can get the special script (TCL/Tk aka Glyph) for your geometry, then I guess you will be in the good position. But definitely I share my experience that how to transport data from one code to other as I have the good experience in working with gambit, Gridgen, Turbo Grid and ICEM simultaneously.

vij October 11, 2011 18:23

Soni I have similar issue.Please check the PM.

soni_sth October 12, 2011 17:11

Hi Far! I tried to export the file from gridgen.They can be exported as grd file but turbogrid requires in .curve format.

Far October 12, 2011 17:34

can you send me the gg file? how did you build this file in gridgen?

soni_sth October 12, 2011 17:49

It was built in blade modeler.I hve an iges file.I used gridgen to make a mesh.

Far October 12, 2011 18:07

hmmmm, why dont you come directly to turbogrid ?

soni_sth October 12, 2011 18:24

That's what I am trying to do Far.I have a database file.I don't see any option in gridgen to change in .crv format.


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