vortex generators

[jeff naul]

I'm about order a set for my Zenith Zodiac because everybody that has added them all see huge improvements. 10 m.p.h. cruise increase with 5-7 slower landing speeds with no thump that the HDS is known for on touchdown. So this has me thinkin about my Sonerai, I fly off a grass strip with trees on one end a low power line on the other. When I land to the south over the trees it can get tricky. They post some results with a sonex that are also impressive. The problem with the Zodiac is it flies nose high in cruise which slows it down, after the vortex generators it levels the plane out which gives it the cruise increase. So what do you guys think on a sonerai?

heres the link http://stolspeed.com/

 

[jeff naul]

Sonex


The VG´s are working incredible on my SONEX.

Because I have a private airstrip ( indeed it´s a little patch of green farmland) length 150 m , I could really feel the difference of "no-vortex" and "vortexed wing". I could get the the take-off distance down about 25 m. The climb-rate didn´t change, but the climbspeed is much better now.

Also the max speed is now in the average about 15 km/h more than before, at the same fuel consumption.

The datas:
Sonex aircraft with 90 hp Subaru EA 81 custom made installation
cruise before 185 km/h now 200 km/h
stall speed 92 km/h 80 km/h
Take off distance 300 m 275 m
TO distance in my field 140 m 110 m
landing distance
on my field (Uphill) 100 m 70 m

Climbrate is 650 ft/min

Result: Absolutely positive!

Klaus, Germany

 

[ncam]

I had VG's on my C150 they were good, but not as good as on some aircraft. I noticed that I could haul the 150 off the ground, and I flew it slackly and it was very forgiving, not stalling in unbalanced slow steep turns etc. I will look at them on Dreadful when I get it going. It would be nice to have a lower nose in cruise!
Regards
Neville

 

[racegunz]

I'm very interested in which VG's are being used,there has to be a difference in performance vs. design, sounds like they would be helpful for Libertie as it "drags" the wings a bit if under 100mph (really stubby wings). Gap seals is another mod that at least on some designs makes a big performance difference, especially on climb-out, i.e. short field w/obstacle.

 

[Schmleff]

Keep in mind that the Sonerai wing is partially laminar flow. For more comparative data, it may be helpful to find the results from a laminar flow wing aircraft like a Piper Comanche.

 

[ncam]

There was a beautiful S2 with strap hinges everywhere which gave good narrow gaps, flown into wires by its owner Ray Burgner It was a real inspiration. My S2 had fabric gap seals, I never flew without them, but it flew OK.
Neville

 

[jeff naul]

Jeff, found a little bit on a Comanche, 8 mph lower stall, 5 mph lower touchtown. No mention of cruise improvement. This article talked more about engine out safety so they didnt go much into the over all improvements.

 

[Schmleff]

Wow, that is significant. I would be curious to see the cruise and top speed numbers.

 

[MarkW]

Pics of Ray Burgner's SII

http://www.greatplainsas.com/vwrburgner.html