NACA/Airfoil Profiles

[pawilkes]

I've searched the site and the web for NACAss airfoil profiles to use as a template to design rooflines but so far I haven't found anything. Does anyone know of a website that has a bunch for download or know of a book that would include a bunch that I could copy and/or scan. I live right by a University so i could use there library if I knew what I was looking for.

[Peter7307]

I have cut / pasted a few sites from my booklist which may help.
NACA evolved into NASA and RACE Magazine is a local (Australian) car tech mag. They ran a series of article on aero wings and profiles and how to build them.


naca.larc.nasa.gov.
http://www.hanleyinnovations.com/racecar1.html
Race Magazine - Home

Look specifically for wings / section with the numbers E 423 (E is for Eppler) and NACA
4415.
The NACA numbers mean:
First number: amount of camber of the mean line
Second number: Where it occurs
Last two numbers: Thickness to chord ratio.
So for 4415: 4 degrees , 40 % back from the leading edge ; with 15% t/c.

Hope this helps,

Pete.

[pawilkes]

Thanks Pete, that is definately a good start

[aerohead]

pawilkes,if you do a search for MetroMPG's permanent Kammback,we've got a template you can use.It's developed from a 2.5:1 teardrop body of revolution,which has the lowest profile drag and lowest skin friction.---------- Wing profiles are going to have more skin friction do to their length.-------- If you follow the scaling protocol on our template,you'll end up with a roofline with zero separated flow,maximum static regain,and minimum skin friction,for minimum drag.

[elsp]

this is a nice site with drawings in .DWG file
ww.davincitechnologies.com/AirfoilOptimizerStdAirfoils.htm
(add a "w" in front)

[aerohead]

Originally Posted by elsp

this is a nice site with drawings in .DWG file
ww.davincitechnologies.com/AirfoilOptimizerStdAirfoils.htm
(add a "w" in front)

Bear in mind that airfoils are designed for flight.Abbott and von Doenhoff warn,in their Theory of Wing Sections that if a wing is used outside the context for which it is created,then none of its performance criteria have any validity.
Wings are designed for laminar environments far beyond ground effect.They have zero profile drag and are governed by skin friction.
In an automotive environment all the air is turbulent,you are emersed in ground effect,skin friction plays only an insignificant role,and the greatest challenge is moving the point of separation as far back as possible,which is achievable only with the longer,gently tapering tail as depicted in the streamlining template.If you make it longer,drag goes back up do to increased skin friction.
You might want to look at W.A.Mair's work on boat tails.This is what works with motor vehicles.Leave that wing stuff for the 'upper' sky.

[Bicycle Bob]

Yeah, "The Theory of Wing Sections" by Abbott and Von Doenhoff has a lot of great shapes for wings, not for fuselages. Most of the book is devoted to the laminar flow shapes in the "6" series. A 66021 is (6) a laminar shape, (6) thickest at 60% back, where it transitions to turbulent flow, (0) not cambered - a symmetrical wing and (21) 21% as thick as it is wide. The cd is about .04 at low angles of attack. Some earlier shapes were as low as .03, but were too fussy for safe flight.
PLEASE DON'T GET EXCITED ABOUT THESE SHAPES unless you are ready to use them exactly, with no seams, ripples, roughness, bugs or vibration, and understanding that turbulent flow will spread at 15 deg from the wheel openings.
To get away from wing shapes, which are designed for good lift with a stable center of pressure and options for flaps, with low drag, and find low-drag volume containers, search on "Bodies of Revolution." (Note to NSA robot - that is not a political comment.)