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-   -   [GAMBIT] Meshing airfoil using .dat file problem (http://www.cfd-online.com/Forums/ansys-meshing/70085-meshing-airfoil-using-dat-file-problem.html)

creggie November 13, 2009 15:58

Meshing airfoil using .dat file problem
 
1 Attachment(s)
Hi,
I am using the cornell tutorial (amazing thing) to mesh an airfoil. I have been through the tutorial using the airfoil .dat file provided and had no problems. However when trying to mesh an airfoil that I wish to investigate, I seem to run into some problems. When importing the file only the vertices seem to appear, however with the provided airfoil the faces appear to, this means that when it comes time to seperate the airfoil from circ1, I cannot select the airfoil to do so, and I cannot split the airfoil surfaces later on in the tutorial. please find a .txt version of the airfoil .dat file i wish to investigate.

your help is much appreciated

Liam

teguhtf November 13, 2009 19:29

Hi creggie,
Your number of vertex is wrong (Your number is 87 & the correct is 97).
Your number of matrix is wrong (Your matrix is 2 & the correct is 1).
You cannot divide your matrix become two. because number of your vertex is odd.
hope it helps
teguhtf

creggie November 14, 2009 09:32

Fantastic, worked perfectly. When meshing the circ1 part of the geometry I now recieve the error "each boundary must have an even number of intervals". In the tutorial he uses an odd number of intervals on EF, as do I. Sorry for these amatuer problems

teguhtf November 14, 2009 10:35

Number of matrix show number of edge.

creggie November 14, 2009 10:56

sorry im not sure I understand. I have meshed the airfoil, I am now attempting to mesh the face that connects the circular edge to the airfoil. I have meshed each edge with the same amount of points as the airfoil top and bottom. I still however, recieve the same error as above

teguhtf November 14, 2009 11:15

You should check the value of element and node of your foil and your circular. By using option summarize. Btw, what is number of edge of airfoil??

creggie November 14, 2009 11:23

I have split the airfoil into 4 edges, as the tutorial suggests, at x=0.3*c. The tutorial made me summarize the mesh edges in order to mesh the circular edge with the correct number of intervals. The top part of the airfoil contains 40 elements from the leading edge to 0.3*c, and 36 elements from 0.3*c to the trailing edge. Thus the top half of the circular edge was meshed with 40+36=76 elements. Using the same technique the bottom half of the airfoil, and thus the bottom of the circular edge was meshed with 75 elements. This is where I assume the error is occuring (the bottom of the airfoil) but this error would be apparent in the tutorial as well, it cleary hasn't occured there though.

teguhtf November 14, 2009 11:31

Number of element in upper and lower edge must same. upper has 76, so does lower. I think there much error of the tutorial. Try others!! chek this tutorial. I think its good for you!! I've run this tutorial and it works well.
http://web.missouri.edu/~solbrekkeng...is_logsdon.pdf
hope it helps
teguhtf

creggie November 14, 2009 12:24

Tried the tutorial you sent, it's great. However I still have the same problem. When trying to mesh the circular area, I run into problems. However, I can now mesh if i use a pave type, it does however come out extremely skewed. Any suggestions (your help has been great so far). I have also had problems in the subtracting the airfoil from the circular area part, not sure if that affects the meshing of the circular area (ACIS error 8032- inconsistent edge face relationship)

teguhtf November 14, 2009 13:22

pave is unstructured mesh. It has flexible usage. But most of airfoil use map or sub map mesh. Quality of mesh will take effect of your simulation.
Read thesis carefully, please!! It will spend much time!! That is the only way.

sohail_27 June 27, 2010 19:24

Airfoil in vertical motion
 
Hi,
I am trying to run simulation (2D) for 3 bladed NACA 0012 airfoil in vertical motion with respect to central axis using gambit and fluent. I know how to create mesh for single airfoil and run simulation on it, but i don't know how to create mesh for airfoil and to rotate it in fluent. I would be glad if anyone could help me out.
Here is a youtube video of what i actually want to do. Please help me out guys, its part of my thesis.
http://www.youtube.com/watch?v=1eyEtzdHDEE

Regards.


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