topic Re: Problem Airfoil NACA 6412 in Fusion Design, Validate & Document Forum

Problem Airfoil NACA 6412

xav_lambert123 — Wed, 05 Jun 2024 15:35:00 GMT

Hi, I have been trying to import the NACA 6412 spline into Fusion 360. To do this, I downloaded a Fusion 360 app called Airfoil DAT to Spline. However, when I import it into Fusion 360, I notice that the spline is incomplete. I tried to close it manually with an arc, but I would like to keep the original complete shape. When I modify the spline manually in Fusion 360, I get a strange shape that alters its aerodynamics. Can anyone import this airfoil directly into Fusion 360 while keeping the complete shape of the airfoil? If not, could someone manually adjust it so that the airfoil's shape is complete and identical to the original closed model? If anyone wants to try to solve the problem, I added the link to the airfoil, a screenshot of the issue, and the Fusion 360 file.

Thank you in advance.

The link to the airfoil: http://airfoiltools.com/airfoil/details?airfoil=naca6412-il

Betreff: Problem Airfoil NACA 6412

Josef_A_K_ — Wed, 05 Jun 2024 17:35:22 GMT

I have checked the data file, which contains the coordinates for the spline. It seems that the spline is not closed.

Please try to open the data file with an text editor and copy the end coordinates of one spline also to the end of the second spline.

Than load it with your tool into Fusion.

I have added tree pictures, hope it works.

Re: Problem Airfoil NACA 6412

davebYYPCU — Wed, 05 Jun 2024 18:38:12 GMT

You did not say how big the chord line should be.

If you change anything, you are changing the aerodynamics. Catch 22.

Delete the last point on the bottom curve. Draw a line across the gap..

After that Fusion will choke on the number of spline points - anyway.

Might help….

Re: Problem Airfoil NACA 6412

Drewpan — Wed, 05 Jun 2024 23:54:19 GMT

Hi,

Simple fix for this is to go to the Airfoiltools website and create your DAT file but remember to click the option of close

the airfoil. I have been caught out with this exact same problem. If you use this to close your airfoil it uses the

software to calculate the closure point and it does not muck up you aero.

Cheers

Andrew

Re: Problem Airfoil NACA 6412

wersy — Fri, 07 Jun 2024 08:11:22 GMT

@Drewpan schrieb:
Hi,

Simple fix for this is to go to the Airfoiltools website and create your DAT file but remember to click the option of close
the airfoil. I have been caught out with this exact same problem. If you use this to close your airfoil it uses the
software to calculate the closure point and it does not muck up you aero.

Cheers

Andrew

@Drewpan
That's a very good idea!
Can you please describe the steps how to download the correct dat file?

Re: Problem Airfoil NACA 6412

user015M86Y — Sat, 08 Jun 2024 22:29:23 GMT

Hi, as @wersy recommand, I build a new airfold with the same parameters of NACA 6412

Max camber 6%, Max camber position 40%, Thickness 12%, Number of points 81

Cosine spacing On, Close trailing edge On

The airfoil is perfectly closed

Re: Problem Airfoil NACA 6412

wersy — Sun, 09 Jun 2024 13:39:53 GMT

@user015M86Y schrieb:
Hi, as @wersy recommand, I build a new airfold with the same parameters of NACA 6412
Max camber 6%, Max camber position 40%, Thickness 12%, Number of points 81
Cosine spacing On, Close trailing edge On
The airfoil is perfectly closed

Can you describe how you proceeded?

Re: Problem Airfoil NACA 6412

user015M86Y — Sun, 09 Jun 2024 18:07:59 GMT

Hi, I build the spline airfoil sketch with the app Airfoil DAT to Spline

First you create the airfoil dat file in Airfoil Tools : NACA 4 digits generator

Enter the parameters from my last post, don't forget to close trailing edge

Then run the Fusion 360 addins Airfoil_Dat_to_spline_v2.0 and follow the menu

Hope this help

Re: Problem Airfoil NACA 6412

wersy — Sun, 09 Jun 2024 19:16:19 GMT

Thank you, now I found the "NACA 4 digit airfoils" to generate it.

Re: Problem Airfoil NACA 6412

Drewpan — Mon, 10 Jun 2024 12:10:10 GMT

Hi Wersey,

I have only ever used standard airfoils from this site. I have always just cut and pasted the data into a text file. You can

download the dat file clicking the button. The close airfoil check box is a bit non-intuitive to find but it is there.

At least one of the tools allows a roll your own airfoil designer.

It is here on the airfoil generator but not the airfoil plotter pages.

Cheers

Andrew

Re: Problem Airfoil NACA 6412

wersy — Mon, 10 Jun 2024 13:41:27 GMT

Thank you!