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-   -   [ICEM] Importing Points for Airfoils (http://www.cfd-online.com/Forums/ansys-meshing/115066-importing-points-airfoils.html)

leo_NM March 22, 2013 14:45

Importing Points for Airfoils
 
1 Attachment(s)
Good Afternoon

I'm Trying to import the selig 1223 coodenates on ICEM like one tutorial I found on youtube but I'm having problems with it.

http://www.youtube.com/watch?v=tYrbScUH9RE

I counted the lines (with xcel ofcourse) and wrote this number and the number of curves like the tutorial said but....

When I select the file and press apply anything happens. I'm uploading the image of the two selig files, one is the original and the other is the one I modified following the tutorial instructions.

What's the correct layout of text to import points on icem CFD ? Is (*).dat a good format ?

thanks

FJSJ March 25, 2013 08:29

2 Attachment(s)
If you followed the video tutorial is easy to do:

1) Number of points per curve

2) How many curves are

3) Points of curves. Starting with the leading edge.

If you are using a. txt to import the points, here I give you a file that you serve as an example.

leo_NM March 25, 2013 09:08

Thank you !!

It worked !!!

micro11sl March 29, 2013 12:46

Leading edge radius?
 
1 Attachment(s)
Quote:

Originally Posted by FJSJ (Post 416207)
If you followed the video tutorial is easy to do:

1) Number of points per curve

2) How many curves are

3) Points of curves. Starting with the leading edge.

If you are using a. txt to import the points, here I give you a file that you serve as an example.

Hi,
Using your coordinate, I've got a sharp leading edge which is not smoothed--see the attachment. Any ideas? Will you suggest more dense data points?

Sheng

FJSJ April 9, 2013 03:06

Hi,

sorry for answering so late. I have always used this method and it works. Maybe it's because you do not have much points in that area (leading edge) or a graphic resolution problem.Try it with other profil with more points.

micro11sl April 9, 2013 04:21

Quote:

Originally Posted by FJSJ (Post 419305)
Hi,

sorry for answering so late. I have always used this method and it works. Maybe it's because you do not have much points in that area (leading edge) or a graphic resolution problem.Try it with other profil with more points.

So this is what I am worried. Because you separate the aerofoil to two curves joined together at the leading edge and trailing edge, how to ensure the curves are tangential to each other at the leading edge?

Regards,
Sheng

FJSJ April 10, 2013 03:43

take a look on Simonīs video:

http://www.youtube.com/watch?v=tYrbScUH9RE

Just only 35 seconds, from 0:15 to 0:50. I always put the pressure area (in this case curve) and suction area, hence, 2 curves. About tangent point, always begin the curves from 0,0,0 and end them at 1,0,0 (x,y,z).

micro11sl April 10, 2013 05:56

3 Attachment(s)
Quote:

Originally Posted by FJSJ (Post 419551)
take a look on Simonīs video:

http://www.youtube.com/watch?v=tYrbScUH9RE

Just only 35 seconds, from 0:15 to 0:50. I always put the pressure area (in this case curve) and suction area, hence, 2 curves. About tangent point, always begin the curves from 0,0,0 and end them at 1,0,0 (x,y,z).

Hi FJSJ,
Thanks for your reply. I've gone through the video again. I tends to think more points near the leading edge will be better. So I grab a coordinate file of a Clark Y aerofoil and import it into ICEM. Please see the attached picture. The leading edge is of good quality as no non-tangent places can be observed.

So the key point is to keep sufficient coordinate points near the leading edge.

Regards,
Sheng

FJSJ April 10, 2013 06:23

Good one. As I said you, in this area must be some points more than you put in the first image attached. There were only 3 points exactly near to the leading edge.
I'm glad it's been resolved!

Far April 10, 2013 14:16

Sufficient points are necessary and more important is to make the airfoil in four sections :

Leading edge
Suction side
Pressure side and
trailing edge.

micro11sl April 23, 2013 18:02

Quote:

Originally Posted by Far (Post 419705)
Sufficient points are necessary and more important is to make the airfoil in four sections :

Leading edge
Suction side
Pressure side and
trailing edge.

Hello,
In the four segments you mentioned, how large or how long should the leading edge be? I guess short?

If using the "leading edge" zone, I am worried because the post processing may be more complicated. When not using the "leading edge" zone, after solution, it is convenient to plot pressure coefficients or skin friction on aerofoil surface because I can simply select the "upper" and "lower" surface as the wall zone. If a "leading edge" zone is in presence, I probably have to export data on all wall zones with coordinate X Y, and then plot in other programs, because it is not necessary to say which part on the plot is on the leading edge in the legend (the upper and lower division is already sufficient).

Sheng


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