helppyFormex - Support: sr #109147, CFD airfoil trailing edge mesh...


sr #109147: CFD airfoil trailing edge mesh creation?

Submitted by:  Klaus Burkart <klausb>
Submitted on:  Tue 20 Sep 2016 04:08:13 PM UTC  
Category:  Open discussion Priority:  5 - Normal
Severity:  3 - Normal Privacy:  Public
Assigned to:  None Open/Closed:  Open
Operating System:  GNU/Linux

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Tue 20 Sep 2016 06:28:26 PM UTC, comment #1: 

1. The Curve.approx(n) method positions n points on the curve, equidistant in parameter space, and then creates a PolyLine through the points. For an initial PolyLine this means that corners may be cut off. Specifying the ndiv= parameter in the approx method will however guarantee that you get a certain number of subdivisions for each segment, keeping the original vertices of the Polyline.

2. The ndiv parameter can be specified as a single number for each segment, or as a list of numbers for all the edges. Since you probably want to control element size, I have included a script that aimis at getting almost equal length along all segments. It is based on the number of elements on the trailing edge. In the image, the nearly equidistant nodes are shown.
For now, I just connected the airfoil boundary with the outer boundary. In order to create a boundary layer of specified size around the airfoil, it would be best to first create an offset over the required boundary layer thickness.

(file #38573,

Benedict Verhegghe <bverheg>
Project Administrator
Tue 20 Sep 2016 04:08:13 PM UTC, original submission:  


When the airfoil section profile is closed

C = PolyLine(X,closed=True)

the trailing edge corners are not captured correctly (the thin red line in the attached picture shows the correct shape).


What would be a py script approach to come up with a trailing edge mesh shape shown in the attached picture "trailing_edge_mesh_tobe.png"?

Let's only focus on boundary mesh made up of square cells and assume these are continued throughout the domain.

Klaus Burkart <klausb>


(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach Files:

Attached Files
file #38573: added by bverheg (1KiB - text/x-python)
file #38574:  naca_0015_4.png added by bverheg (22KiB - image/png)


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    Follow 4 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2016-09-20 bverheg Attached File- => Added, #38573
        Attached File- => Added naca_0015_4.png, #38574
    2016-09-20 klausb Attached File- => Added trailing_edge_mesh_asis.png, #38566
        Attached File- => Added trailing_edge_mesh_tobe.png, #38567

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