I am new at RC and just started building a BLUEBABY via my needle cutter cnc and the one thing that caught my fascination was this KFM2 and actually all of it. Great Video!!
Great video 2024 BUMP 💪 I am an old timer aeromodeller who came into aeromodelling building Balsa Chuck Gliders and then of course moved on to FF,CL, RC and so on and now at Drones. I am also working with kids to ring them into the fold of Aviation (any form for goodness sake LOL) In light of that I am creating a simple simon chuck glider to be made from Kebab Skewers and Foam Plates. Did not want to make errr "complex" airfoil shapes ... so was looking more into Kf ! I think your video gave me that extra nudge I needed to do it. (I was holding back for a long long time) So cheers and I wonder where you are now since 5 years of this video !!?
Props for pointing out what the reasons may be for using a KF airfoil. Many just rave about it without going into specifics. Now for some critique: Comparing random geometric/velocity working points does not really give a valid comparison. As you certainly know, airspeed and lift are directly linked, so it only makes sense to compare points of equal lift. To get the whole picture you have to compare complete polars. And the singular of vortices is vortex. You may want to look into the x-foil digital wind tunnel. I'm not sure how well it will do witth the KF airfoils, most such simulations don't do well with separated flow. x-foil can deal with low re separation bubbles, but the explicitly exclude fully separated flow. don't know how KF fits into this scenario.
Colton... Thank you for the work you have done on the KF airfoil concept. If you are interested, give me your email address and I will send you a number of papers from around the world that show very positive results with stepped airfoils. Not only favorable on props, but improvements when applied to a Darrieus Wind Turbine.
I am honored to have the creator of the KF Airfoil see my video and comment! I look forward to doing further research on the airfoils (I'm a little behind right now but will get caught up haha). Email is corsair2014 @ gmail Thank you!
Dude, this video as awesome, but you have to make Part 2 with those simulations you were talking about, diference in stall etc... Really looking foward to that. Cheers
Since the availability of xFoil there is almost no reason to use these airfoils except for very crude models. An inverse designed airfoil will outperform experimental forms in every case. Even a flat plate works well for 3D foamies. And it is very easy to hotwire true airfoil shapes out of XPS styrofoam. Mark Drela has several low Reynolds number airfoils available. As does Selig in his reports titled same. Edit* Clark-Y is a terrible airfoil for almost any use. It has a sharp stall, large negative pitching moment, average maximum lift, and terrible low Reynolds number performance. - If you want a similar archaic airfoil with better performance you are probably better off with a 4412. Or a 4409 for low Reynolds number models. Otherwise, thin Drela or Selig foils.
I've tried a couple different KF style wings with good results. I think my favorite was my FT Flyer. I wonder what would happen if you put serrations across the top of the step. Kind of like VGs, just cut into the upper piece.
I am new at RC and just started building a BLUEBABY via my needle cutter cnc and the one thing that caught my fascination was this KFM2 and actually all of it. Great Video!!
Great video 2024 BUMP 💪
I am an old timer aeromodeller who came into aeromodelling building Balsa Chuck Gliders and then of course moved on to FF,CL, RC and so on and now at Drones.
I am also working with kids to ring them into the fold of Aviation (any form for goodness sake LOL)
In light of that I am creating a simple simon chuck glider to be made from Kebab Skewers and Foam Plates.
Did not want to make errr "complex" airfoil shapes ... so was looking more into Kf !
I think your video gave me that extra nudge I needed to do it. (I was holding back for a long long time)
So cheers and I wonder where you are now since 5 years of this video !!?
Props for pointing out what the reasons may be for using a KF airfoil. Many just rave about it without going into specifics.
Now for some critique:
Comparing random geometric/velocity working points does not really give a valid comparison. As you certainly know, airspeed and lift are directly linked, so it only makes sense to compare points of equal lift. To get the whole picture you have to compare complete polars.
And the singular of vortices is vortex.
You may want to look into the x-foil digital wind tunnel. I'm not sure how well it will do witth the KF airfoils, most such simulations don't do well with separated flow. x-foil can deal with low re separation bubbles, but the explicitly exclude fully separated flow. don't know how KF fits into this scenario.
Colton... Thank you for the work you have done on the KF airfoil concept. If you are interested, give me your email address and I will send you a number of papers from around the world that show very positive results with stepped airfoils. Not only favorable on props, but improvements when applied to a Darrieus Wind Turbine.
I am honored to have the creator of the KF Airfoil see my video and comment! I look forward to doing further research on the airfoils (I'm a little behind right now but will get caught up haha).
Email is corsair2014 @ gmail
Thank you!
Could I contact you please regarding your airfoil? I am very interested in using it on one of my designs. Thank you in advance.
Dave Edwards
Dude, this video as awesome, but you have to make Part 2 with those simulations you were talking about, diference in stall etc... Really looking foward to that. Cheers
Thanks man, appreciated! I hope to someday have time to dive into this again 🙃
Mate, I just randomly stumbled across your videos, but this a brilliant! You would honestly be a great teacher :) I hope you keep making these.
Liked the approach, answered several questions I had about the KF aerofoils; look forward to stall analysis.
Excellent video - very interesting subject
look forward to more
Since the availability of xFoil there is almost no reason to use these airfoils except for very crude models. An inverse designed airfoil will outperform experimental forms in every case. Even a flat plate works well for 3D foamies. And it is very easy to hotwire true airfoil shapes out of XPS styrofoam. Mark Drela has several low Reynolds number airfoils available. As does Selig in his reports titled same.
Edit* Clark-Y is a terrible airfoil for almost any use. It has a sharp stall, large negative pitching moment, average maximum lift, and terrible low Reynolds number performance. - If you want a similar archaic airfoil with better performance you are probably better off with a 4412. Or a 4409 for low Reynolds number models. Otherwise, thin Drela or Selig foils.
Thanks for the explanation.
I've tried a couple different KF style wings with good results. I think my favorite was my FT Flyer.
I wonder what would happen if you put serrations across the top of the step. Kind of like VGs, just cut into the upper piece.
That's an excellent idea! I will add that to my list of things to research
Great channel, i am new to aerodynamics, CFD and F360 but still your video is very useful. Are you using the paid CFD program from Autodesk?
Do you think these would work well for cheap STOL aircraft?
I don't see it in nature. Good enough reason for me to move on.
Hi Colton, Which software do you use to simulation?, Thanks
Great !
Thanks I appreciate it!
Pls make the video
Colton... did you receive the KF documents that I sent you last week? I sent you a number of them. ~ Dick
Yes I did, thank you! I haven't had a chance to go through them yet as work has been busy but I will soon thanks again!
Can you please share the KFM airfoil .dat file . thanks in advance
たくさん話し
your step size is way too high
PaDents are pretty imporDent, right?
I know you can say "but", bud.
Americans DGAF.