When you use the PACC command to toggle on the point accumulation, before using the ASEQ command to generate your polar points, XFOIL will prompt you to enter in the polar save filename (step 7 in my polar plot basics video). If you enter in a filename, like NACA4412_polar.txt , then the software will not only turn on polar point accumulation but it will also save the data from each point of the ASEQ (AOA sequence) into the file automatically. You can then open this file using any .txt program and see the CL, CD, CDp, Cm, Top_Xtr, and Bot_Xtr for each angle of attack you ran the analysis at. If you run into problems, check out the videos I did on the polar save/dump files where I cover some of the finer details. Hope this helps!
Can anyone explain how to load an airfoil on xfoil but on Mac? Naca airfoils work just fine, but when trying to load one of the airfoils from the site, it doesn't work.
Before trying to load an airfoil into XFOIL from an online database, like the UIUC Airfoil Database, you need to check that the file is the right file type (.txt/.dat) and that the data in the file is in the right format (plain or labeled format preferred), and the coordinate points are in the right order (TE to TE, either clockwise or counter-clockwise around the airfoil shape). In fact it is recommended to format any airfoil you get off an online database so that it is in the "Plain" file format (each coordinate gets it's own row with the x-coordinate first, then a space, and then the y-coordinate; with nothing else in the file). I've got a video on my channel all about loading an airfoil into XFOIL. Check it out and let me know if you still have issues.
Hi friend, how to de-rotate airfoil please ? green line is not aligned with TR et LD edge for me. I have tried the command dero, but it doesn't work, do you have an idea how to use it, please?
I obtained polars for different values of Ncrit from 4 to 12. I would like to know how I can get all of them in one plot. This way I can see the polars for all values of n one a single plot. Can someone help me? I am using a Mac and pplot doesn't seem to be recognise the polar name even when I use it correctly.
Hello, I do have one question, If I want to plot an airfoil with an control surface (say slat or spoiler) in Xfoil, how I can do it?.When I imported the coordinates for an airfoil with a spoiler, XFOIL show wrong chord length and .GDES command shows an airfoil which is not according to the coordinates given. But .PPAR command shows that airfoil as the coordinate points. However, the solution is not converging. Could you please give me a solution for the same?
It is currently not possible using MS Excel only. This is because XFOIL wants a space-delineated .txt/.dat file but MS Excel only exports a worksheet to a tab-delineated .txt file (MS Excel will export to a space-delineated .prn file but XFOIL doesn't recognize .prn files). I find that if I am using a file type that isn't supported in XFOIL it will prompt me so, but if I try and use a tab-delineated .txt file XFOIL will crash (current version is 6.99). If you are still wanting to use MS Excel, to be able to, say, use the sort function, you will need to export to a tab-delineated .txt file (x-coordinate in column a, y-coordinate in column b, each coordinate pair has it's own row) then use another software like MS Word to "Find and Replace" the tabs with a single space, which isn't too hard and goes pretty quick. Other than file type and file format, it's just a matter of making sure the coordinate points are in the right order (TE to TE, either clockwise or counter-clockwise). I also wouldn't try to add points in MS Excel, instead I'd use the paneling parameters in XFOIL. I used your comment as an inspiration for a video on my channel. I've got some others on loading an airfoil in XFOIL, the different file formats that XFOIL recognizes, adjusting the paneling parameters, running analysis, and more to come. If you have any additional issues loading an airfoil, let me know.
Good video! But i still have a problem. i've downloaded a dat file of the selig 1223 airfoil, and Xfoil is refusing to load it. i've tried loading in .txt and .dat. there's nothing wrong with the file itself, the coordinates are exactly as shown, but xfoil sais the file is non existent. Can someone help me?
Wow thank you! I was starting to freak out about how to use it, but now it makes so much more sense.
You've saved my coursework \o/
8:02 How do you create a text file for the AoA values vs. cp, cd and cm?
When you use the PACC command to toggle on the point accumulation, before using the ASEQ command to generate your polar points, XFOIL will prompt you to enter in the polar save filename (step 7 in my polar plot basics video). If you enter in a filename, like NACA4412_polar.txt , then the software will not only turn on polar point accumulation but it will also save the data from each point of the ASEQ (AOA sequence) into the file automatically. You can then open this file using any .txt program and see the CL, CD, CDp, Cm, Top_Xtr, and Bot_Xtr for each angle of attack you ran the analysis at. If you run into problems, check out the videos I did on the polar save/dump files where I cover some of the finer details. Hope this helps!
How can I change the moment to the aerodynamic center instaed of being calculated about the quarter chord?
thank you a lot man, it is really helpful...
really helpful! Keep up the good work !
I really wnat to learn all this and if any opportunities can work with you
Can anyone explain how to load an airfoil on xfoil but on Mac? Naca airfoils work just fine, but when trying to load one of the airfoils from the site, it doesn't work.
Before trying to load an airfoil into XFOIL from an online database, like the UIUC Airfoil Database, you need to check that the file is the right file type (.txt/.dat) and that the data in the file is in the right format (plain or labeled format preferred), and the coordinate points are in the right order (TE to TE, either clockwise or counter-clockwise around the airfoil shape). In fact it is recommended to format any airfoil you get off an online database so that it is in the "Plain" file format (each coordinate gets it's own row with the x-coordinate first, then a space, and then the y-coordinate; with nothing else in the file). I've got a video on my channel all about loading an airfoil into XFOIL. Check it out and let me know if you still have issues.
a second question please: suppose that I have normalized my airfoil, which command should help me to export my data?
Hi friend, how to de-rotate airfoil please ? green line is not aligned with TR et LD edge for me. I have tried the command dero, but it doesn't work, do you have an idea how to use it, please?
I obtained polars for different values of Ncrit from 4 to 12. I would like to know how I can get all of them in one plot. This way I can see the polars for all values of n one a single plot. Can someone help me? I am using a Mac and pplot doesn't seem to be recognise the polar name even when I use it correctly.
Thank you!!
Great channel
can you run an entire 360 degree simulation in xfoil or are the results inaccurate after a certain maximum attack angle?
Hello,
I do have one question, If I want to plot an airfoil with an control surface (say slat or spoiler) in Xfoil, how I can do it?.When I imported the coordinates for an airfoil with a spoiler, XFOIL show wrong chord length and .GDES command shows an airfoil which is not according to the coordinates given. But .PPAR command shows that airfoil as the coordinate points. However, the solution is not converging. Could you please give me a solution for the same?
my PltLIb does not change.. I am using 6.99 version..
It was like this with me as well
I am facing the same issues. But, I realized I had .dat file that was running, not .txt. It might be because of that.
You hit enter again to update it. Notice how at 3:11 he skipped another command line but you hear a faint click.
Life saver
@@MaplestoryTaiwan
I am trying to load several airfoils from online and it doesn't work (sometimes crashes). Does anyone know how to format data in excel?
It is currently not possible using MS Excel only. This is because XFOIL wants a space-delineated .txt/.dat file but MS Excel only exports a worksheet to a tab-delineated .txt file (MS Excel will export to a space-delineated .prn file but XFOIL doesn't recognize .prn files). I find that if I am using a file type that isn't supported in XFOIL it will prompt me so, but if I try and use a tab-delineated .txt file XFOIL will crash (current version is 6.99).
If you are still wanting to use MS Excel, to be able to, say, use the sort function, you will need to export to a tab-delineated .txt file (x-coordinate in column a, y-coordinate in column b, each coordinate pair has it's own row) then use another software like MS Word to "Find and Replace" the tabs with a single space, which isn't too hard and goes pretty quick.
Other than file type and file format, it's just a matter of making sure the coordinate points are in the right order (TE to TE, either clockwise or counter-clockwise). I also wouldn't try to add points in MS Excel, instead I'd use the paneling parameters in XFOIL.
I used your comment as an inspiration for a video on my channel. I've got some others on loading an airfoil in XFOIL, the different file formats that XFOIL recognizes, adjusting the paneling parameters, running analysis, and more to come. If you have any additional issues loading an airfoil, let me know.
thank`s!
Thanks sir
where are the part 1 and part 3 videos?
Good video! But i still have a problem. i've downloaded a dat file of the selig 1223 airfoil, and Xfoil is refusing to load it. i've tried loading in .txt and .dat. there's nothing wrong with the file itself, the coordinates are exactly as shown, but xfoil sais the file is non existent. Can someone help me?
same here please help if you found the answer
good
This some good shit