Excellent job, test, procedure and video! The best documentation of VG's at work I have ever seen. I fly a Sonex ONEX and am experiencing a severe right wing drop approaching stall. The indicated speed at stall is 42 mph. I will be installing the Stolspeed version today, but first some data before, then after, is in order. Thanks again, I am so much more educated and optimistic about the improvements I am about to make. Carl
What great work, and- a huge amount of effort to get these results! Even in this 'rough' form, it appears that they may assist a transition training pilot? I'm thinking just a little more stability at reduced speeds & power during approach, over the fence, over the numbers & touch down may create confidence in early flights. Once created- remove the training wheels and slightly increase speeds? Additionally, as suggested in the paper, tapered VG's, mounted slightly aft (8.25 or 8.5) may reduce effectiveness, while decreasing drag and allowing a slight stabilization at reduced stall speeds. Regardless, it seems like a compromise that may appeal to a low time in platform, or low time overall pilot. What a project- thank you for all of the work & effort!
Ummmm........ I'm not really sure it gets you THAT much to make transition training easier. And when the plane DID stall - it was much more of a break. YMMV
@@graemejwsmith Well, there DID seem to be the benefit of low speed stability, albeit at the cost of high speed, fuel economy & responsiveness. Funny, but one of your last statements reflects an unwillingness to lose the responsiveness of the plane... Hmmm.
No - I took them off. They were quick and dirty test pieces of angle looking for gross effect. I also didn't like what they did to the roll rate - as I did acro with the plane. No longer own the plane.
@@graemejwsmith thanks for the reply. Sorry to hear it got sold, I know you are still active on the sonex board. (FYI... I think you sent me the head phone adaptor for the sporty radio. Thanks)
Great video! Thanks a lot for showing us! I guess the test was done with low takeoff weight. But it's still amazing how well the wing flies without VGs. Did you end up installing the VGs finally? Just playing with ideas: is there anybody who has done or studied a tapered outer wing section for the Sonex? Maybe 2 feet more wingspan for very high altitude flying in the Alps or Rockies?
I did NOT fit them. It slowed roll rate which is more important for me doing acro. If you dig around in the builder's forum - someone is making tapered wing tip extensions. PERSONALLY I'm not convinced they are worth the extra parasitic drag. The Sonex wingtip has a 45 degree undercut which "moves" the aerodynamic tip and vortex generating point outboard of the actual physical wing - thus "lengthening" the wing anyway. Or you could even for for the extra wingspan XENOS motor glider with 50% more wingspan!
That's not just the VG's. That's a common observation on many GA wings. Hence the recommendation that on an engine failure you PUSH aggressively to keep the wing flying and maintain control.
Does the Sonex Wing have any built in washout? I see in the clean configuration the tufts stay attached on the outboard section of the wing while the inboard section starts to lose airflow. Also, do you know what airfoil is used? I am really impressed with the speed range on the Sonex.
Left wing, pilot sitting left side, left down aileron required to stay level thus left wing chord line has higher angle of attack, stalls first. OR you keep it upright with rudder and plane starts to turn right too. Paper - link in description expand with SEE MORE
Excellent job, test, procedure and video! The best documentation of VG's at work I have ever seen. I fly a Sonex ONEX and am experiencing a severe right wing drop approaching stall. The indicated speed at stall is 42 mph. I will be installing the Stolspeed version today, but first some data before, then after, is in order. Thanks again, I am so much more educated and optimistic about the improvements I am about to make. Carl
Glad I saw your video, wanted to add VGs on my Sonex. I think I will order some then!
This is very intersting. Thank you for taking the time to put this together.
Thanks for making this!
Great video and interesting paper and findings. THANKS!!!
Nicely done Graeme!
After watching your video, I am on my way to the hardware store to Fab VG's for my Quicksilver. Thanks for the encouragement.
That was nice to see the airflow over the wings. Thank you for the video🌈 from 🇿🇦
at this speed, who needs a super cub.
Nice work , and what a nice stall behaviour has the sonex (also without VG's).
thanks for the video.
GREAT work, now I love my Sonex even more 😉
What great work, and- a huge amount of effort to get these results! Even in this 'rough' form, it appears that they may assist a transition training pilot? I'm thinking just a little more stability at reduced speeds & power during approach, over the fence, over the numbers & touch down may create confidence in early flights. Once created- remove the training wheels and slightly increase speeds?
Additionally, as suggested in the paper, tapered VG's, mounted slightly aft (8.25 or 8.5) may reduce effectiveness, while decreasing drag and allowing a slight stabilization at reduced stall speeds. Regardless, it seems like a compromise that may appeal to a low time in platform, or low time overall pilot.
What a project- thank you for all of the work & effort!
Ummmm........
I'm not really sure it gets you THAT much to make transition training easier. And when the plane DID stall - it was much more of a break.
YMMV
@@graemejwsmith Well, there DID seem to be the benefit of low speed stability, albeit at the cost of high speed, fuel economy & responsiveness. Funny, but one of your last statements reflects an unwillingness to lose the responsiveness of the plane... Hmmm.
Very cool vid... thanks for posting. Did you leave the VG on the wings? Crazy to think that this wing didn't stall all the way down to 20kts.
No - I took them off. They were quick and dirty test pieces of angle looking for gross effect. I also didn't like what they did to the roll rate - as I did acro with the plane. No longer own the plane.
@@graemejwsmith thanks for the reply. Sorry to hear it got sold, I know you are still active on the sonex board. (FYI... I think you sent me the head phone adaptor for the sporty radio. Thanks)
Thats really cool! Thank you for the video! I will check out the paper.
Parabéns. Ótimo trabalho. Tenho um waiex e fiquei satisfeito com os resultados visuais.
Great video and read, Thanks!
Great video! Thanks a lot for showing us! I guess the test was done with low takeoff weight. But it's still amazing how well the wing flies without VGs. Did you end up installing the VGs finally?
Just playing with ideas: is there anybody who has done or studied a tapered outer wing section for the Sonex? Maybe 2 feet more wingspan for very high altitude flying in the Alps or Rockies?
I did NOT fit them. It slowed roll rate which is more important for me doing acro.
If you dig around in the builder's forum - someone is making tapered wing tip extensions. PERSONALLY I'm not convinced they are worth the extra parasitic drag. The Sonex wingtip has a 45 degree undercut which "moves" the aerodynamic tip and vortex generating point outboard of the actual physical wing - thus "lengthening" the wing anyway.
Or you could even for for the extra wingspan XENOS motor glider with 50% more wingspan!
The most amazing thing is the imediate return to lift after the stall.
That's not just the VG's. That's a common observation on many GA wings. Hence the recommendation that on an engine failure you PUSH aggressively to keep the wing flying and maintain control.
@@graemejwsmith ok we will just call this not amazing guess I don't know much about eridinamiks
Does the Sonex Wing have any built in washout? I see in the clean configuration the tufts stay attached on the outboard section of the wing while the inboard section starts to lose airflow. Also, do you know what airfoil is used? I am really impressed with the speed range on the Sonex.
No - It's "flat". No twist or washout. But stalling in the root first is normal in a low wing hershey bar wing
@@graemejwsmith Thank you for the response, I wasn't sure if that was normal span wise behavior. Do you have any idea what airfoil is used?
I finally found a reference to the airfoil, it is a 64-415
@@tjohnson9909 NACA 64-415
It looked like the left wing was losing it first. Why? Also, where can I read your paper? Thanks!
Left wing, pilot sitting left side, left down aileron required to stay level thus left wing chord line has higher angle of attack, stalls first. OR you keep it upright with rudder and plane starts to turn right too.
Paper - link in description expand with SEE MORE
looks to me that your vg's are straight not vectored in to speed up the air
@ 6:20 - They were jigged at 4 degrees to the airflow