# Grid suggestion

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May 1, 2017, 07:53
Grid suggestion
#1
Member

Join Date: Dec 2015
Posts: 33
Rep Power: 10
This just a simple case with a circular obstacle in the middle

What would you suggest to enhance the grid specifically in the area around the circle ?

Thank you
Attached Images
 Capture.JPG (112.6 KB, 27 views)

May 1, 2017, 09:51
Here's one way to do it
#2
Senior Member

Rick Matus
Join Date: Mar 2009
Location: Fort Worth, Texas, USA
Posts: 116
Rep Power: 17
Extrude domains inward and outward from the circle, then build the same topology you already have in the remaining voids. Next, run the elliptic solver on the domains interior to the circle with the floating boundary elliptic solver boundary condition applied to all edges. Finally, run the elliptic solver on the domains exterior to the circle with the floating boundary bc applied.

See attached picture.
Attached Images
 circleinrectangle.jpg (114.2 KB, 28 views)

 May 2, 2017, 06:22 #3 Member   Khaled Ahmad Join Date: Dec 2015 Posts: 33 Rep Power: 10 Thank you so much, I think this is the way I was looking for even though I don't know that much about Pointwise, if you could help me and mention some sources. Actually I am drawing the lines, circle, ellipse,... in AutoCAD and then import it by pointwise then keep assembling the domains, are you making it, somehow, in the same way ? did you draw that ellipse in the pointwise because I don't know exactly what did you mean by "run the elliptic solver" !! Thanks

 May 2, 2017, 08:50 It's all done in Pointwise #4 Senior Member     Rick Matus Join Date: Mar 2009 Location: Fort Worth, Texas, USA Posts: 116 Rep Power: 17 Khaled: The geometry and grid topology were all made in Pointwise. Here are some short videos that describe the techniques used. These videos and hundreds more are available on the CFDMeshing YouTube channel. Creating circles: https://www.youtube.com/watch?v=iQ4g...eO5ZhHpHIVBxHT Creating extruded grid: https://www.youtube.com/watch?v=mLRU...eO5ZhHpHIVBxHT Running the elliptic solver with floating boundaries: https://www.youtube.com/watch?v=NUbZ...eO5ZhHpHIVBxHT Hope this helps, Rick kh.aa likes this.

 May 2, 2017, 09:12 #5 Member   Khaled Ahmad Join Date: Dec 2015 Posts: 33 Rep Power: 10 This really does help Thanks Rick

 May 2, 2017, 10:10 #6 Member   Khaled Ahmad Join Date: Dec 2015 Posts: 33 Rep Power: 10 Sorry rick, but could you please attach for me the PW file to see exactly what did you do ? Thank you

May 2, 2017, 10:15
Pointwise project file
#7
Senior Member

Rick Matus
Join Date: Mar 2009
Location: Fort Worth, Texas, USA
Posts: 116
Rep Power: 17
No problem. It is attached.
Attached Files
 CircleInRectangle.zip (69.7 KB, 8 views)

 May 2, 2017, 10:20 #8 Member   Khaled Ahmad Join Date: Dec 2015 Posts: 33 Rep Power: 10 Is there any wayto join all of this to get the whole domain's structured points ?

 May 2, 2017, 11:07 #9 Senior Member     Rick Matus Join Date: Mar 2009 Location: Fort Worth, Texas, USA Posts: 116 Rep Power: 17 If you select a 2D CAE format (CAE, Select Solver and CAE, Set Dimension), select all the domains, and then use File, Export, CAE all of the points will be written to whichever CAE format you have selected. You probably want to set up CAE BCs in CAE, Set Boundary Conditions before you do that though.

 May 2, 2017, 11:20 #10 Member   Khaled Ahmad Join Date: Dec 2015 Posts: 33 Rep Power: 10 Oh, I am writing my own code so I am gonna need just the coordinates of each point, of course organized in an "structured" way so what I was doing is exporting the grid to a data file but the problem is when the domain is not joined well, the points become messy. On the other hand, if it's well joined like just one mesh for the whole domain the points exported well from pointwise .

 May 2, 2017, 12:56 #11 Senior Member     Rick Matus Join Date: Mar 2009 Location: Fort Worth, Texas, USA Posts: 116 Rep Power: 17 A drawback to this topology is that it does not fit into a single structured grid. It is inherently multi-block. You could try using one of the structured CAE export formats Pointwise supports or write a CAE plugin to export the grid and BCs in your code's native format. Information on writing a CAE plugin is available in Appendix II of the Pointwise User Manual and here: http://www.pointwise.com/plugins/html/index.html kh.aa likes this.

 Tags circle, grid, obstacle, pointwise