Vortex Generators

[Aireal Anarchist]

morning fellow pilots

I see more and more home built RC fixed wings with 3D printed vortex generators, I am aware of the theory and the aerodynamics of vortex generators, my question is......
are you doing this for performance enhancement or modeling aesthetics ?

Im wondering if ( It feels better) is all entirely subjective on small RC models because a feeling is subjective and owning a 3D printer would add a little bias, or has anyone actually made improvements, I could see where an airframe that handles poorly at slow speeds MAY benefit from VG's redirecting faster airflow over the control surfaces

Im an experienced pilot flying for many many years and I only have one plane that I am that confident that I feel like I am REALLY "at one with my wings" & could possibly feel a response difference enough to give V generators a try
I dont have a 3D printer so I could get straight to testing, I will have to pay for 3D printing at this time



I dont care about opinions of the aerodynamics of vortex generators, Im interested in your practical experience guys

 

[LitterBug]

I see a LOT of excess weight in those examples. Should be able to just print a flat piece and stick it right in the foam. Maybe all the added weight is making them fly more stable....

 

[Aireal Anarchist]

I see a LOT of excess weight in those examples. Should be able to just print a flat piece and stick it right in the foam. Maybe all the added weight is making them fly more stable....

well this was my line of thinking but didnt want to sway the responses, if the resistance is infact slowing down the plane it may make a pilot feel like its handling better.... a feeling is subjective

we do think similar regarding this, I was thinking of credit card bits jambed in the foam would be a better option reducing all the added weight
and is the added weight negating the performance benefits of the VG's

 

[Aireal Anarchist]

I suppose one could CA bits of thread across a wing and watch the air flow on FPV, then add the VG's and review the results, but again are we actually improving the flight characteristics on these tiny RC planes we fly or is the resistance and weight on the small models in fact slowing it down....
I have a feeling that although on full size aircraft the benefit is documented on some designs, it may not be as beneficial on our small models and impossible to prove one way or another

but ....inquiring minds want to know

 

[Crawford Bros. Aeroplanes]

well this was my line of thinking but didnt want to sway the responses, if the resistance is infact slowing down the plane it may make a pilot feel like its handling better.... a feeling is subjective

we do think similar regarding this, I was thinking of credit card bits jambed in the foam would be a better option reducing all the added weight
and is the added weight negating the performance benefits of the VG's

I see a LOT of excess weight in those examples. Should be able to just print a flat piece and stick it right in the foam. Maybe all the added weight is making them fly more stable....

I use bits of popsicle stick embedded in the foam. I can;t say anything for performance improvements though, this one is still awaiting a maiden.

 

[Aireal Anarchist]

I use bits of popsicle stick embedded in the foam. I can;t say anything for performance improvements though, this one is still awaiting a maiden.

View attachment 172383

the one plane that I fly so well like Im in the cockpit and I feel at one with, I dont want to mark it up with testing bits

too bad I didnt start the discussion before they were added so that you could have maiden'd with out the VG's and had a base of sorts to compare flight characteristics

 

[Grifflyer]

I know for act that adding VGs to the outboard section of my Shrubsmacker improved the slow speed handlings tremendously, it no longer tip stalls during low speeds.

 

[Crawford Bros. Aeroplanes]

Now that I'm reminded I still need to add VGs to Draco

 

[L Edge]

I suppose one could CA bits of thread across a wing and watch the air flow on FPV, then add the VG's and review the results, but again are we actually improving the flight characteristics on these tiny RC planes we fly or is the resistance and weight on the small models in fact slowing it down....
I have a feeling that although on full size aircraft the benefit is documented on some designs, it may not be as beneficial on our small models and impossible to prove one way or another

but ....inquiring minds want to know

I did what you actually said, put tufts on the wings and took some flights looking at the takeoffs and landings using video. Then we installed vortex generators and did the same.

There were really no noticeable results on takeoffs and landing.

If you do add something that is favorable, it will show. For instance, put some leading edge flaps fixed down, you will have a much better STOL and your top speed will slightly less. They work.

 

[LitterBug]

One thing I have noticed on my umx turbo timber is the flaps really don't seem to do much good when in stabilized modes. Kind of counter intuitive to me. I can definitely feel them in full manual mode. I also think the stabilizer does a better job for low speed flight than the flaps. Totally seat of the pants feel and not a great objective test. Need to do more testing on a calm day.

 

[Aireal Anarchist]

One thing I have noticed on my umx turbo timber is the flaps really don't seem to do much good when in stabilized modes. Kind of counter intuitive to me. I can definitely feel them in full manual mode. I also think the stabilizer does a better job for low speed flight than the flaps. Totally seat of the pants feel and not a great objective test. Need to do more testing on a calm day.

I can see that, the flaps tilt the craft upwards as it attempts to gain altitude and the FC inputs down elevator to keep it level
I havent used flaps with stab mode before will have to try it and see if I get the same results, and I should

I like manual mode, full flaps for FPV and flying really slow, it gets me better video footage to review later counting livestock

 

[PsyBorg]

Check out the FT3d videos here. They had Aaron Bates (pro pilot) fly and give suggestions for better performance in the design. the second video they did and added the Vortex generators and Seemed to have noticeable performance changes.

I noticed @L Edge 3d printed a set. They made mention of using them only at the tips of the wings not full span as the air flow close to the fuselage is still clean from propeller flow.

 

[L Edge]

Check out the FT3d videos here. They had Aaron Bates (pro pilot) fly and give suggestions for better performance in the design. the second video they did and added the Vortex generators and Seemed to have noticeable performance changes.

I noticed @L Edge 3d printed a set. They made mention of using them only at the tips of the wings not full span as the air flow close to the fuselage is still clean from propeller flow.

Actually, what also adds to the performance is the end plates which especially helps in a knife edge. Once the design is finished, it really boils down to the right prop(even wide ones), throws and the pilot's ability. If there's a difference of adding something, it will show.