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Author Topic: Airfoil Coordinate Conversion  (Read 2450 times)

Offline Stoney

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Airfoil Coordinate Conversion
« on: October 14, 2008, 12:36:06 PM »
I was curious as to whether or not anyone knew how to convert NACA airfoil coordinates into XFoil coordinates?  I've done some searches online and have yet to see anything that's definitive and/or I can understand.

I designed an airfoil for my formula 1 project, and want to do some Xfoil analysis, but can't with the coordinate format I have.

Tango?  Anyone else?
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Offline gripen

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Re: Airfoil Coordinate Conversion
« Reply #1 on: October 14, 2008, 01:52:58 PM »
I have software called Profili 2 (Pro version nowadays). Check it out:

http://www.profili2.com/eng/default.htm

It's for designing RC-planes but as there is Xfoil built in, it can do pretty much everything.
« Last Edit: October 14, 2008, 01:56:30 PM by gripen »
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Offline dtango

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Re: Airfoil Coordinate Conversion
« Reply #2 on: October 14, 2008, 02:29:43 PM »
Hi Stoney - sorry, I have no answer for you here!  I haven't been nearly as brave or tenacious as you taking the xfoil bull by it's horns so I don't have any helpful info.  However I'll go do a little research to see what else I can find.  For sure check out the s/w gripen mentions.

Tango, XO
412th FS Braunco Mustangs
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Offline Stoney

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Re: Airfoil Coordinate Conversion
« Reply #3 on: October 14, 2008, 02:59:21 PM »
My biggest issue is that I'm not using the NACA method of computing the coordinates, and most of the programs that use "stock" airfoils use the NACA method and have a database versus a program that computes them.  For example, the airfoil I designed would be a type of NACA 66115 a=.6 or more accurately a Harry Riblett GA 45-115 (I think).  I have the coordinates using the y values in NACA Report 824 (i.e. .25, .5, .75. etc) but these are not the y values used by XFOIL.  I was just going to use Java foil, but it doesn't draw the laminar airfoils properly that I can tell, especially when using the 66 series and when using the non-standard "a" values.

It appears that Profili uses stock airfoils that you can modify, but since I'm using non-standard airfoil methods to begin with, I'm not sure it will work for me.  I'll do some more investigation with it.  I was just curious as to whether or not anyone knew of anything quick and painless, if there is such a thing with XFOIL.

Thanks guys and cheers...

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Offline dtango

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Re: Airfoil Coordinate Conversion
« Reply #4 on: October 14, 2008, 03:11:37 PM »
OK - gotcha.  Check your PM's.

Tango, XO
412th FS Braunco Mustangs
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"At times it seems like people think they can chuck bunch of anecdotes into some converter which comes up with the flight model." (Wmaker)

Offline gripen

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Re: Airfoil Coordinate Conversion
« Reply #5 on: October 14, 2008, 05:14:11 PM »
The Profili 2 can generate various NACA profiles. Just open the airfoils management, then management pull down menu and choose generate new NACA airfoil. Or you can enter the coordinates choosing the New airfoil from the menu.

Edit: I checked the NACA report 824, you can enter the coordinates to the profili 2 just as given in the report.
« Last Edit: October 14, 2008, 05:21:46 PM by gripen »
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Offline Stoney

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Re: Airfoil Coordinate Conversion
« Reply #6 on: October 14, 2008, 05:17:46 PM »
I'm curious as to how it computes the 6-series shapes.  I'm using Riblett's technique which differs from NACA's technique.  Perhaps I'll download the program and see how it works, and then make a judgement. 


Thanks Gripen...
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"Can we be incorrect at times, absolutely, but I do believe 15 years of experience does deserve a little more credence and respect than you have given from your very first post."

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Offline gripen

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Re: Airfoil Coordinate Conversion
« Reply #7 on: October 14, 2008, 05:23:03 PM »
Ah you all ready replied, it should be possible if you can get the coordinates, no problem.
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Offline Chalenge

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Re: Airfoil Coordinate Conversion
« Reply #8 on: October 14, 2008, 07:46:45 PM »
XFoil has a way to load NACA (XFOIL c> NACA 2412)

2412 is an excellent slope soaring airfoil or sport monoplane foil.  :aok
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Offline dtango

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Re: Airfoil Coordinate Conversion
« Reply #9 on: October 14, 2008, 08:04:39 PM »
The issue is that Stoney's airfoil is not a standard NACA airfoil but a modified one so he has to create a airfoil file for it.

Tango, XO
412th FS Braunco Mustangs
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"At times it seems like people think they can chuck bunch of anecdotes into some converter which comes up with the flight model." (Wmaker)

Offline Chalenge

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Re: Airfoil Coordinate Conversion
« Reply #10 on: October 14, 2008, 08:54:46 PM »
Got it... sorry.
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