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[ANSYS Meshing] Orthogonal Quality Issues in the Infalation Layer

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Old   September 13, 2014, 11:51
Default Orthogonal Quality Issues in the Infalation Layer
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Hi all,

I am trying to develop a CFD model for a 3D Wing. I have imported the wing shape from inventor and creating a volume of "air" around it. When I come to mesh the fluid I am however encountering issues with Orthogonal quality.
  • Without an inflation layer the fluid meshes without an errors.
  • As soon as I apply an inflation layer I get the warning that I have elements with an orthogonal quality lower than 0.05.
I have noticed that the poor quality elements are at the Trailing and Leading Edges of the wings as well as around the wing tip (I am attaching images showing the location as well as close-up snapshots of the problematic leading edge and trailing edge elements).

I am using the standard Workbench meshing software (when I started the project I imported a Fluent project from the side bar).

Any points which could help point me towards the right direction would be greatly appreciated.
Attached Images
File Type: jpg Poor_Orthoganal_Quality.jpg (96.4 KB, 26 views)
File Type: jpg Poor_Orthoganal_Quality_LeadingEdge.jpg (95.8 KB, 27 views)
File Type: jpg Poor_Orthoganal_Quality_TrailingEdge.jpg (97.2 KB, 25 views)
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Old   September 23, 2014, 21:33
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inflation layer details? also where did you get the airfoil data, i suspect you just drew one in a cad package?
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Old   October 4, 2014, 05:32
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Quote:
Originally Posted by hwet View Post
inflation layer details? also where did you get the airfoil data, i suspect you just drew one in a cad package?
Hi, firstly please excuse the delay but these past two weeks were totally hectic and I barely had time to put on my computer.

Regarding the Airfoil Data, I got the coordinates from the following source:
"Wind Tunnel Aerodynamic Tests of Six Airfoils for Use on Small Wind Turbines," by M.S. Selig & B.D. McGranahan for National Renewable Energy Laboratory (Revised October 2004). I used the values for the FX 63 aerofoil.

I then determined the coordinates of the camberline by finding the mid-point between the upper and lower surface points. Using the camberline I applied the thickness I wanted and scaled the aerofoil for the chord length I wanted.

Inflation Layer Details are as follows (image attached):

Scope
Scoping Method: Geometry Selection
Geometry: 1 Body (Fluid)

Definition
Suppressed: No
Boundary Scoping Method: Named Selections
Boundary: Wall (Aerofoil Wall)
Inflation Option: 1st Layer Thickness
First Layer Height: 4.343e-6m
Maximum Layers: 30
Growth Rate: 1.2

I also tried varying the First Layer height between 1e-6m to 10e-3m, I had similar problems with all heights. If I reduce the height too much then the meshing fails.
Attached Images
File Type: jpg Inflation Layer Details.jpg (93.8 KB, 10 views)
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Old   October 4, 2014, 06:10
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firstly dont force the software to apply mapped face meshing, secondly inflation 10^-6 is way too small, even NASA wont go that small, keep it a few mm i think, is this geometry 2D? also turn on proximity settings on curvature, start with about 60 degrees and then reduce it to the refinement you want. post your geometry file is possible, also try applying program controlled inflation if your a new to the software
i am quite sure cfd for airofoils is very common and there are easy available tutorials on the ansys website for meshing and cfd across airfoils.
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