These
vortex kits can increase speeds by up to 7.5 MPH.
This is accomplished by placing vortelators at certain critical locations
which cause the boundary layer to stay attached to flying surfaces for
a greater distance, and to keep the boundary layer thinner. The net result
of these two actions is that it reduces both the profile drag and skin
friction drag components of parasite drag. Another way to think of it
is that the wake behind the aircraft will be smaller thus requiring less
horsepower to propel the aircraft through the air.
The figure shows the flow of black motor oil on a lift strut with,
a short strip of vortelator attached, during a flight test. Notice that
behind the vortelator mini vortices are created as can be seen by the
lines of oil that form behind the vortelator. These mini vortices sweep
the oil to a point in between the mini vortices, and thats how the oil
lines are formed. Whenever one sees these characteristic oil lines forming
behind the vortelator one knows the vortelator is working. The vortelator
allows the air flow to stay attached to the lift strut for approximately
80% of the lift struts chord. In the area where there is no vortelator
the air flow separates from the lift strut at approximately 40% of the
lift struts chord, as can be seen from the pile up of oil at the 40% chord
position.
Here the lift strut is 2.01" thick, and at the 80% chord position the
lift strut is 1.18" thick. That means the wake coming off the lift strut
is only 59% as thick with the vortelator attached as without the vortelator
attached. That also means with a narrower wake less horsepower is required
to propel the lift strut through the air.
Kit 246-100 is FAA approved for the following Cessna aircraft: 140A,
all models of 150, all models of A150, all models of 152, all models of
A152, 170A&B, all models of 172 (USAF T-41A), P172D, R172E (USAF T-41B),
and (USAF T-41C & D), R172F (USAF T-41D), R172G (USA T-41C & D), R172H
(USAF T-41D), R172J, R172K (known as 172XP, 172RG, all models of 75, all
models of 180, all models of 182, R182, T182, TR182, all models of 185,
A185E, A185F, all models of 205, all models of 206, all models of P206,
all models of U206, all models of TP206, all models of TU206, all models
of 305 known as L-19.
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