vortex generators?
Drew and Jan
reduce the stall speed and improve the landing flare.The problem is I don't
know where to start. i.e. how many, how big, how far back on the wing and
stabilizer etc. Are there any basic rules of thumb for installing them or can
anyone reccomend a text where this is covered.
thanks Drew Dalgleish
Craig C.
Drew: I don't think anyone has done any work with the Rebel, so you
are on your own.The first place to start is to do a flow study on the
a/c. Thiw will require either doingthe work via CFD or by flow
visualisation. Once you have established what the flow patterns are,
then you can begin to experiment with location and size and quantity
to adjust the flow to what you need. It is not an easy task, it is
tedious and can have very unexpected results without proper testing.
You relaize that once you start hanging v.g.'s on your aircraft, you
are now THE ONE and ONLY experimental test pilot that has flown that
configuration. If you are really going to get that deep into it, you
are looking at flying a considerable amount of time to do the
developmental work.
BTW...I used to be a flight test instrument engineer and did stuff
like this all the time. Hope you've got a nice gas budget and a couple
of buddies that can fly chase for doing the flow vis studies.
Craig C.
Stephen Ambrose
Adding Vortex Generators to you wing will reduce your stall speed and give
you
better aileron control at lower speeds. My brother add a set to his RANS S7
and reduced his stall speed by 9 MPH. The plane now stalls at around 25 MPH
and we have positive aileron control all the way thought the stall. We
performed a tuft test on the wing before and after the vortex generators and
video taped it in flight, it was incredible. He will not fly with out them
now. We now have 3 or 4 planes in the club flying with them and everyone
loves them.
I don't have a picture of the ones we purchased. They are white and made of
polycarbonate. They are paintable. They are slightly concaved and are a
rectangle on the bottom and a triangle shaped on top. Front view looks like
a inverted T. The tall end of the triangle faces aft.
To install them you want to place them just before the maximum thickness of
your air foil. This is import because if they are to far aft they will
become ineffective at high angle of attacks. Place them at a 15 degree angle
in pairs facing each other. Example: / \ / \ / \ / \
Spacing between them is not that critical but you will probably need 100
VG's. On a RANS S6ES with lace on fabric we placed the so the stayed even
between the ribs. We made a poster board template and marked them with a
pencil and glued then on with silicon. We ran a string lengthwise so they
would all be lined up.
They will adversely NOT effect your cruise speed.
We used a total of 96 VG's on each plane. The RANS has a 29' 3" wing and the
RANS S6 has a 29' wing.
We purchased them from:
Contact: Art Bianconi
Computer Certainty Inc.
P.O. Box 494 Milford, NJ 08848
(732) 699-0400
These are non TSO and therefore fairly inexpensive, something like 50 VG's
for $30.
Tell Art Bianconi that Mark Ambrose said hello, I'm Marks brother Steve. We
get no kick back or anything like that. Just want to say hello to Art.
Good Luck
Steve Ambrose
--
"Drew and Jan" <dre...@execulink.com> wrote in message
news:drewjan.10...@execulink.com...
Frank Stutzman
> They will adversely NOT effect your cruise speed.
True. The only downside that they have that I know is that they also
reduce your manuvering speed (Va). May or not be a problem, depending
on the plane and the conditions you fly in. I've decided against putting
them on my Bonanza as I often fly in turbulent conditions and the need to
get below the manuvering speed in a hurry does happen on occaision.
Frank Stutzman
Drew Daglish
wrote:
>I'd like to experiment with vortex generators on my Murphy rebel to try to
>reduce the stall speed and improve the landing flare.The problem is I don't
>know where to start. i.e. how many, how big, how far back on the wing and
>stabilizer etc. Are there any basic rules of thumb for installing them or can
>anyone reccomend a text where this is covered.
>thanks Drew Dalgleish
thanks to everyone that responded on the group and by email I guess
theres a lot more to this than just slapping on some tabs and happily
flying away.
O-ring Seals
wrote:
Frank,
I have the MicroVortex vg's on my C310G. There is no mention in the
STC of a reduction in maneuvering speed. I wonder what is peculiar
about the Bonanza? I suppose that it has something to do with the
reduction in stalling speed. l think that the structure is still OK
at your old maneuvering speed in rough air, you just can not count on
full control deflections resulting in a stall before something bends.
O-ring (ride out the turbulence) Seals
Frank Stutzman
> On 16 Jun 2000 15:41:47 GMT, Frank Stutzman <stut...@mate.kjsl.com>
> wrote:
> Frank,
> I have the MicroVortex vg's on my C310G. There is no mention in the
> STC of a reduction in maneuvering speed.
Interesting. I must confess that I made that statement on Va speed
without actually looking at an STC. It just seemed to me that since the
VG's lowered the stall speed, the Va would also go down.
> I wonder what is peculiar about the Bonanza?
Don't know. I see that MicroVortex now has an STC for Bonanza's. I talked
to them years ago regarding doing the Bonanza. They had looked into it
and decided that the testing would be too difficult. Something about the
spin characteristics. Guess they changed their mind.
Frank Stutzman
Bonanza N494B
Hood River, OR
Dave Hyde
> doesn't change.
From the article:
"Va is a purely theoretical figure that represents the maximum speed
at which abrupt control deflection will not stress the aircraft beyond
its designed load limit...you'd have to enter the maneuver at an
airspeed significantly higher than Va, then perform an abrupt pull-up
or accelerated stall that would produce load-limit G-forces and reduce
the airspeed to Va precisely at the point where the airplane stalled."
I respectfully suggest that the author of this article learn a little
about the term 'corner speed' and the windup turn maneuver. A little
experience with both of these will point out the inaccuracies in the
quoted section. Face it, anything that enables a wing to develop a
higher lift coefficient (what properly-installed VG's do) will lower the
minimum speed at which you can attain limit normal acceleration (g),
which is the usual criterion that sets the not-so-theoretical
'theoretical' Va.
The article then goes on to suggest that Va actually is lowered, while
the regulations do not require that the published limit be changed.
Dave 'two circle' Hyde
na...@brick.net