It has been known for some time now that vortex generators reduce stall speeds and improve the aircraft’s handling performance. Vortex generators allow the wing to develop more lift at lower airspeeds. This reduces takeoff speed and improves the rate of climb. Vortex Generators also retain positive aileron control and enhance your rudder authority in higher angles of attack. You will immediately notice an improvement in your aircraft.
HOW DO THEY WORK?
As air normally flows over the wing of an aircraft in flight, the air "sticks" to the surface of the wing. This adherence to the wing's surface produces lift. If the airflow loses its adherence and separates from the wing, aircraft performance can suffer in the form of increased drag, loss of lift and higher fuel consumption.
Researchers at NASA Langley Research Center developed Micro Vortex Generators to control this flow detachment by producing miniature, controlled tornadoes, called "vortices". The Micro Vortex Generators sweep away uncontrolled airflow separation over the airplane's wings and flaps with the benefit of reduced drag and increased lift (i.e., less engine power needed to produce the same lift).
Micro Vortex Generators technology contributed to performance and safety improvements as well as cost and noise reduction for the domestic aerospace industry. Its relatively simple design and ease of installation make Micro Vortex Generators one of the most cost-effective means of aircraft safety and performance enhancement
The Air Wave Vortex Generators dramatically improve the control surfaces as well and can be applied to the vertical and horizontal stabilizers.
Testimonial Used on a Taylorcraft L-2B:
A friend shot the photos, I hope they are clear enough.
I think 16 - 18 degrees is good.....they should in pairs, with the spacing no closer then indicated. If I permanently install these, I will separate the pieces 1/4” more, and the pairs by and additional 1/2”.
These are located 14% of the wing’s m.a.c., aft of the leading edge. There was no improvement here, over 12%. For more symmetrical airfoils, this seems good, but for highly cambered, flat bottom airfoils (like the J-3’s), I think 8 - 10% would be better
Over all I reduced the stall speed by 10 mph. I gained nearly 2 mph I.A.S. reduction in stall speed by the addition of VG’s over the fuselage!
Optimum stall speed reduction was noted with VG’s reaching 2/3’s of the wing span. With this configuration, VG’s were added in front of the aileron gaps, to evaluate roll enhancement. No significant difference could be seen. These were removed and the VG’s were continued to the wing tips. There was no further stall speed reduction, however, at cruise, the wing is so much more efficient, with a lower AOA, that i now get 10 mph more speed at each power setting. Previously, I got 70 mph at 2100 rpm / 80 at 2200 / 90 at 2300 and now i get 80, 90, and 100 mph respectively!
In summary, the addition of the Airwave Micro Vortex Generators to a Taylorcraft L-2B, will reduce the “indicated” stall speed to 30 mph. (Very high AOA, certainly adds to position error), so maybe it’s 32 or 33 mph
Still, that’s nearly a 20% reduction in stall speed and a 12% increase in cruise speed.
Plus, on takeoff, I don’t have to hop over the power lines anymore.