Recent content by 3V152

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  1. 3

    Acceptable surface deviations from an ideal airfoil (Wing construction)

    Here is BigFoil's JavaFoil data comparison for GA35-215 and NACA63A-215 at Re=6M, incompressible. At Cl=0.4 or so, GA35-215 Cd is about 11% lower. Cl max is 1.47 for GA35-215 vs 1.36 NACA63A-215. All normal caveats for computer generated data apply...
  2. 3

    New airfoil website

    What's new at BigFoil Added Cm vs Cl plots. Added NACA 63-series airfoils NACA63A011 thru NACA63A018. Added new airfoils from Peter Wick. Added Lednicer and VisualFoil format DAT files. Work also continues, slowly, on the aforementioned validation study.
  3. 3

    Large format print - and post

    I used Vivyx for a 42x90”. $87 for the print, which was cheaper than any local supplier that had the capability, and $12 for domestic shipping. https://www.vivyxprinting.com/
  4. 3

    New airfoil website

    Will do. 500k Reynolds number to match the UIUC wind tunnel data. will be a good test.
  5. 3

    Airfoil selection for an aircraft out there?

    Keep in mind that the NACA-TR-824 presented wind tunnel data for NACA63-215 is for a split flap, not a plain flap as calculated by JavaFoil and presented at https://www.bigfoil.com I decided not to digitize the split flap data because I can't generate reliable computer results that will match...
  6. 3

    New airfoil website

    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...
  7. 3

    New airfoil website

    What's new at BigFoil Added "Find Airfoils" feature, allowing user to downselect airfoils that match input parameters: Max thickness x-location of max thickness Max camber x-location of max camber
  8. 3

    New airfoil website

    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...
  9. 3

    Airfoil selection for an aircraft out there?

    Not sure of any fullscale aircraft that would use S8036. It was designed for powered model aircraft. bigfoil.com (shameful plug) does have S8036 wind tunnel data, but it is all at low Reynolds numbers, appropriate to model aircraft. The wind tunnel data is from UIUC Low-Speed Airfoil Data, Vol 3.
  10. 3

    New airfoil website

    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...
  11. 3

    New airfoil website

    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.
  12. 3

    New airfoil website

    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...
  13. 3

    New airfoil website

    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...
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