New airfoil website

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Joined
Jun 23, 2018
Messages
14
Location
SEATTLE WA
Hello everyone,

I was trying to find a nice airfoil my homebuilt plane, then things got a little out of hand and I ended up making a website with all of the airfoils I could find, all of their JavaFoil-computed data for varying Re, Mach, roughness, flap setting, etc... and where I could find it, wind tunnel and CFD data. So now I have 5318 airfoils and many many GB of data cataloged.

BigFoil

The sections presented herein are provided largely by the UIUC Airfoil Coordinates Database or generated programmatically by Martin Hepperle's JavaFoil. A handful of sections were sourced from NACA-TR-824 and other freely available sources.
For each shape, scripted JavaFoil batch runs were used to compute the lift, drag, and moment polars for a variety of Reynolds numbers, Mach numbers, surface roughnesses. Data was also generated for plain flapped sections with varying chord length and deflection angle.
Where available, wind tunnel data has been imported, largely from the UIUC Low-Speed Airfoil Tests and NACA-TR-824.
CFD data has also been imported for a select number of airfoils, such as for NACA0012 from the NASA Langley Turbulence Modeling Resource.

For each airfoil, I share the DAT and DXF files, show the parameters for a Venkataraman (four-spline) fit, list the top 20 most similarly-shaped airfoils, and show this data:
Cl vs alpha, Cd vs alpha, Cm vs alpha, Cl/Cd vs alpha, Cd vs Cl - and cubic curve fits for these.
The above data, plotted for various Mach numbers to examine compressibility effects.
The above data, plotted for various surface roughnesses.
Data for plain-flapped sections of a variety of flap lengths and flap deflections. This data can be used to approximate aileron effects.

To aid in selecting airfoils, I present a visual catalog showing every airfoil, and there is a "Big Table" showing data like airfoil family, thickness, Cl max, Cl/Cd max, and Cd at various lift coefficients.
There is also a tool for comparing airfoil shapes, a Re and Mach calculator, and a tool to interrogate the database to find and compare data for airfoils.


I hope you all enjoy it. Please contact me or share in this thread any issues, comments, or suggestions.

-Mike
 
Last edited:
Joined
Jun 23, 2018
Messages
14
Location
SEATTLE WA
Well done!

Is there any chance that you could add some of the 7 series NACA airfoils such as the NACA 747-A415 and the -A315?


747A315 and 747A415 are in there, both categorized under “NACA”.

Both have NACA-TR-824 wind tunnel data which is a decent match to the JavaFoil data.

I am working on a better search feature, but right now under the Big Table page, you can search.

Here are direct links:

BigFoil



Thank you,

Mike
 

PiperCruisin

Well-Known Member
Joined
Jan 17, 2017
Messages
413
Location
Idaho
I was trying to find a nice airfoil my homebuilt plane, then things got a little out of hand and I ended up making a website with all of the airfoils I could find, all of their JavaFoil-computed data for varying Re, Mach, roughness, flap setting, etc... and where I could find it, wind tunnel and CFD data. So now I have 5318 airfoils and many many GB of data cataloged.

BigFoil
Nice. I'm going to be wasting a lot of time playing with this. I do like Javafoil. Airfoil Tools is a good site also, but that graph results look wonky.

2 Questions:
1. What kind of plane are you working on?
2. What would you do with the Venkataraman parameters? Maybe do some Monte Carlo runs to test tweaks to the airfoil? That would be cool.

Rich
 
Joined
Jun 23, 2018
Messages
14
Location
SEATTLE WA
Nice. I'm going to be wasting a lot of time playing with this. I do like Javafoil. Airfoil Tools is a good site also, but that graph results look wonky.

2 Questions:
1. What kind of plane are you working on?
2. What would you do with the Venkataraman parameters? Maybe do some Monte Carlo runs to test tweaks to the airfoil? That would be cool.

Rich
Thanks Rich
I am working on something most similar to a Glasair Sportsman. The Venkataraman parameters are useful for creating smooth CAD geometry compared to splining through an array of points. They can also be used for parametric optimization which I plan to do.
 

AJLiberatore

Well-Known Member
Joined
Nov 27, 2011
Messages
133
Location
Canton MI
Hello everyone,

I was trying to find a nice airfoil my homebuilt plane, then things got a little out of hand and I ended up making a website with all of the airfoils I could find, all of their JavaFoil-computed data for varying Re, Mach, roughness, flap setting, etc... and where I could find it, wind tunnel and CFD data. So now I have 5318 airfoils and many many GB of data cataloged.

BigFoil

The sections presented herein are provided largely by the UIUC Airfoil Coordinates Database or generated programmatically by Martin Hepperle's JavaFoil. A handful of sections were sourced from NACA-TR-824 and other freely available sources.
For each shape, scripted JavaFoil batch runs were used to compute the lift, drag, and moment polars for a variety of Reynolds numbers, Mach numbers, surface roughnesses. Data was also generated for plain flapped sections with varying chord length and deflection angle.
Where available, wind tunnel data has been imported, largely from the UIUC Low-Speed Airfoil Tests and NACA-TR-824.
CFD data has also been imported for a select number of airfoils, such as for NACA0012 from the NASA Langley Turbulence Modeling Resource.

For each airfoil, I share the DAT and DXF files, show the parameters for a Venkataraman (four-spline) fit, list the top 20 most similarly-shaped airfoils, and show this data:
Cl vs alpha, Cd vs alpha, Cm vs alpha, Cl/Cd vs alpha, Cd vs Cl - and cubic curve fits for these.
The above data, plotted for various Mach numbers to examine compressibility effects.
The above data, plotted for various surface roughnesses.
Data for plain-flapped sections of a variety of flap lengths and flap deflections. This data can be used to approximate aileron effects.

To aid in selecting airfoils, I present a visual catalog showing every airfoil, and there is a "Big Table" showing data like airfoil family, thickness, Cl max, Cl/Cd max, and Cd at various lift coefficients.
There is also a tool for comparing airfoil shapes, a Re and Mach calculator, and a tool to interrogate the database to find and compare data for airfoils.


I hope you all enjoy it. Please contact me or share in this thread any issues, comments, or suggestions.

-Mike

Mike,
Outstanding. I say that as someone who has for quite a while reading, researching, and using all the free-bee airfoil software I can to learn more and about them. I get what you have done here and IMHO it is monumental. The compare feature is off the hook. If you could get Mike Shuck to give you his catalog that would be icing on the cake. The only 2 of interest I found missing and you may have them are the NACA 2r112 and the even harder to find De Havilland Mosquito sections . Thank You Sir.
 

PiperCruisin

Well-Known Member
Joined
Jan 17, 2017
Messages
413
Location
Idaho
Thanks Rich
I am working on something most similar to a Glasair Sportsman. The Venkataraman parameters are useful for creating smooth CAD geometry compared to splining through an array of points. They can also be used for parametric optimization which I plan to do.
Any hints on how to go from the Venkataraman parameters to create airfoil coordinates? I was looking on Venkataraman's site, but not finding it. I would like to take the Venkataraman parameters and vary some of them slightly to see the performance impact. Select the best on and do it again.
 
Joined
Jun 23, 2018
Messages
14
Location
SEATTLE WA
Any hints on how to go from the Venkataraman parameters to create airfoil coordinates? I was looking on Venkataraman's site, but not finding it. I would like to take the Venkataraman parameters and vary some of them slightly to see the performance impact. Select the best on and do it again.
To convert from the Venkataraman parameters to coordinates for a DAT file or similar, I write out the parametric equation for each spline segment. These are parametrized by arc parameter “s”. varying s from 0 to 1 across, say, 100 points gives the x and y coordinates of each point.
I’ll write up the math and post it.
 

Moosedude

Member
Joined
Apr 30, 2020
Messages
13
There's also airfoiltools.com It's more directed to the RC crowd with RE of 1,000,000 being the max, but they have almost every airfoil in the database. And I've found it super easy printing off the files at any size. No flap data, but still a useful tool. Thanks for this one though, it's pretty awesome
 
Joined
Jun 23, 2018
Messages
14
Location
SEATTLE WA
What's new at BigFoil

New features:
  • Database now holds 6278 airfoils.
  • Added search feature.
  • Added camber lines and max camber calculation.
  • Improved thickness calculation.
  • Added thickness profile to Shape page.
  • Added "Lift Curve Slopes" to Basic Data for each airfoil.
  • Improved and debugged the "Find airfoil data" feature.
  • Improved plot legend for "Similarly shaped airfoils".
  • Fixed bug where NACA-TR-824 Re=9M wind tunnel data was mislabeled.
  • In Basic Data, included wind tunnel data for rough airfoils.
  • Improved speed of "Compare airfoil shapes".
New airfoils and new data:
  • Added airfoils from the TraCFoil database, courtesy of J-C. Etiemble.
  • Added Riblett ultralight airfoils GA 30U-612, GA 30U-615, and GA 30U-618, courtesy of Rich Buxton.
  • Added more thickness variations of all Riblett airfoils.
  • Added six TsAGI airfoils, courtesy of Jeri.
  • Added NACA NACA2R112 and NACA2R212 from NACA-TR-460.
  • Added Don Ayers airfoils.
  • Added Drela horizontal tail HTxx airfoils.
  • Added Stephane Combet SC17 and SC17s airfoils.
  • Corrected coordinates for Yost EH 3.0/12.
  • Reprocessed data for NACA43012A.
  • Added Eberhard Mauk airfoils.
  • Added OpenFoam CFD validation case for NACA0012.
 

PiperCruisin

Well-Known Member
Joined
Jan 17, 2017
Messages
413
Location
Idaho
To convert from the Venkataraman parameters to coordinates for a DAT file or similar, I write out the parametric equation for each spline segment. These are parametrized by arc parameter “s”. varying s from 0 to 1 across, say, 100 points gives the x and y coordinates of each point.
I’ll write up the math and post it.
I kind of answered my own question in the attached Excel file so 3V152 can work on more meaningful stuff. My coordinate distribution is crap, but it gives the overall idea.
 

Attachments

  • BezierFoil.xlsx
    172.7 KB · Views: 9

J.L. Frusha

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Joined
Feb 17, 2006
Messages
894
Location
Luling, Texas
@3V152

Mike,

Thank you for such an organized, detailed and useful website. While I probably cannot figure it out, I have friends that can. My memory sucks, after 4 strokes.

Jeff
 
Joined
Jun 23, 2018
Messages
14
Location
SEATTLE WA
I have been working on a validation study of NACA wind tunnel data vs XFOIL vs JavaFoil vs some full blown RANS CFD with SU2 I have been running. For NACA0012, I also have NASA's CFD validation study for comparison.

I'd like to answer questions such as "can I believe the computer data in this region?", "how far off could the prediction be?", and "do relative differences between predictions equate to similar relative differences in real life?". "Real life" here means wind tunnel testing, which has a litany of correction factors and issues of its own - as can be seen in NASA-TM-100019 "A Critical Assessment of Wind Tunnel Results for the NACA0012 Airfoil".

I am processing unflapped versions of these airfoils, all at Re=6M and Mach 0.15.
NACA0006, NACA0009, NACA0012
NACA1408, NACA1410, NACA1412
NACA2412, NACA2415, NACA2418, NACA2421
NACA4412, NACA4415, NACA4418, NACA4421, NACA4424
NACA23012, NACA23015, NACA23018, NACA23021
NACA747A315, NACA747A415
NACA64-415, NACA65-415
Maybe AS5045 and AS5048
S8036 (at Re=500k)

Attached is an example of the output for NACA0012.
BigFoil CFD, NASA CFD and XFOIL do well on predicting lift coefficient up to 15 degree angle of attack. JavaFoil encountered difficulty at 15 degree and way underpredicted the lift coefficient. One could tune the stall and transition models in JavaFoil to better match the wind tunnel data, but I selected the Calcfoil stall model and Eppler extended transition model for all cases.
Drag is a much different story. Both CFD methods overpredict drag, as does JavaFoil. XFOIL underpredicted drag but was closer on average to the wind tunnel data than the other methods.

For the other airfoils processed so far, the trends are the same - computer codes do a decent job on lift until near stall, and overpredict drag, except for XFOIL. Averaging JavaFoil/CFD and XFOIL data might do a better job of matching wind tunnel drag data across the angle of attack range.
 

Attachments

  • NACA0012validation.png
    NACA0012validation.png
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Last edited:

PiperCruisin

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Joined
Jan 17, 2017
Messages
413
Location
Idaho
I am processing unflapped versions of these airfoils:
NACA0006, NACA0009, NACA0012
NACA1408, NACA1410, NACA1412
NACA2412, NACA2415, NACA2418, NACA2421
NACA4412, NACA4415, NACA4418, NACA4421, NACA4424
NACA23012, NACA23015, NACA23018, NACA23021
NACA747A315, NACA747A415
NACA64-415, NACA65-415
Maybe AS5045 and AS5048

Could you add S8036 to the list? Seems like a could-be-too-good-to-be-true airfoil, but I like it.
 
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