# Curve is Lines!! , visual Or real?

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July 24, 2013, 10:57
Curve is Lines!! , visual Or real?
#1
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mohamed khedr emam
Join Date: Oct 2011
Location: Egypt
Posts: 121
Rep Power: 7
Hi experts ,
I have simple question

My geometry contains blade where the leading edge of the blade is a CURVE but Fluent shows it as group of lines (figure 1)

Is this just visual problem or real problem and hence effect on results.. I should noted that my geometry was built SolidWorks and i'm sure that it was curve not lines

thanks in advance
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 July 24, 2013, 14:49 #2 Super Moderator   Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,299 Blog Entries: 6 Rep Power: 43 It simply shows that your mesh is coarse in that region. Or may be you be have zoomed too much

July 24, 2013, 20:07
#3
Senior Member

mohamed khedr emam
Join Date: Oct 2011
Location: Egypt
Posts: 121
Rep Power: 7
Thanks far for replay
Quote:
 Originally Posted by Far It simply shows that your mesh is coarse in that region. Or may be you be have zoomed too much
no it is not the mesh (it also appears in same way in ICEM) , and also i'm not zooming too much

I can upload my Case file if you need

 July 25, 2013, 11:22 #4 Senior Member   mohamed khedr emam Join Date: Oct 2011 Location: Egypt Posts: 121 Rep Power: 7 here is the case file http://www.4shared.com/file/DseLJUYW/Case.html I wonder that the circle (at the hub) also appera as a group of lines while the enclosure's curves domain (which contains the blade) is typical curves in general

 July 27, 2013, 15:31 #5 Senior Member   mohamed khedr emam Join Date: Oct 2011 Location: Egypt Posts: 121 Rep Power: 7 Any recommendation?

 July 27, 2013, 16:36 #6 Super Moderator   Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,299 Blog Entries: 6 Rep Power: 43 It is the problem of meshing. If it was not the meshing problem, then it could be due to geometry

July 27, 2013, 16:43
#7
Senior Member

mohamed khedr emam
Join Date: Oct 2011
Location: Egypt
Posts: 121
Rep Power: 7
Quote:
 Originally Posted by Far It is the problem of meshing. If it was not the meshing problem, then it could be due to geometry
Dear Far,
I choose from fluent Mesh Display menu to display the edges not the faces , is this mean it display the mesh (where is the mesh it is just an edge) !! see Figures pls

 July 27, 2013, 16:55 #8 Super Moderator   Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,299 Blog Entries: 6 Rep Power: 43 I have check your mesh file, you have attached in above post.

July 27, 2013, 17:00
#9
Senior Member

mohamed khedr emam
Join Date: Oct 2011
Location: Egypt
Posts: 121
Rep Power: 7
Quote:
 Originally Posted by Far I have check your mesh file, you have attached in above post.
OK thanks Far , sorry for this noise

Quote:
 Originally Posted by Far If it was not the meshing problem, then it could be due to geometry
But i still don't know what is your recommendation : is this Mesh or Geometry error

thanks in advance

 July 27, 2013, 17:14 #10 Super Moderator   Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,299 Blog Entries: 6 Rep Power: 43 I am saying that if you have faulty (degenerated) geometry like sharp leading edge instead of curved one then even fine mesh cannot do anything. For example by packing more mesh points in sharp leading edge you cannot make it round. Got it!!! So if you have perfect geometry (you need to confirm it) then it is the problem of mesh.

 July 27, 2013, 17:27 #11 Senior Member   mohamed khedr emam Join Date: Oct 2011 Location: Egypt Posts: 121 Rep Power: 7 Thanks Far , this is Last inquiry you confirmed that it is not a VISUAL (screen) trick , it is REAL?

 July 27, 2013, 17:32 #12 Super Moderator   Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,299 Blog Entries: 6 Rep Power: 43 It is real

 July 27, 2013, 19:19 #13 Senior Member   Join Date: Dec 2009 Posts: 129 Rep Power: 11 did not get the case file. in general using ICEM using mesh quality, select the surface deviation (surface dev) to essentially show you the deviation/error in the elements face center to the actual surface of the geometry. you can color the mesh with mesh quality (it is a little flaky so you may need to set it, unset it and set it back again). if your surface is not split so the nose can be in a separate part, then you need to reduce the max deviation in the Part Mesh Setup for the blade surface. Or use the geometry line and surface tools to split the surface in ICEM along a ISO line if you can create a reasonable line. depending on what you want to look at I would recommend using a hexa for your wind turbine blade.

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