deturbulated std cirrus flies against Diana 1

For the latest parallel flight of my deturbulated Standard Cirrus vs. a
modern glider, go to
http://sinhatech.com/SinhaFCSD-Progr...08.asp#article .

20 minutes of parallel flying should be enough to make the point.

Download and replay the logs in SeeYou, or what have you.

Jim Hendrix
Oxford Aero Equipment, LLC
417 N. 11th Street
Oxford, MS 38655

662-234-0492 voice
662-234-2195 fax

www.oxaero.com

On Jun 9, 2:59 pm, Jim Hendrix wrote:
For the latest parallel flight of my deturbulated Standard Cirrus vs. a
modern glider, go tohttp://sinhatech.com/SinhaFCSD-Progress-06072008.asp#article.

20 minutes of parallel flying should be enough to make the point.

Download and replay the logs in SeeYou, or what have you.

Jim Hendrix
Oxford Aero Equipment, LLC
417 N. 11th Street
Oxford, MS 38655

662-234-0492 voice
662-234-2195 fax


Am I the only one who is completely underwhelmed by this "exiting"
news that comes well timed after the June article in SSA magazine by
Bill Collum? Is anybody able to explain to me even in basic terms
what the physics behind the claimed effect are? Mr. Collums
explanations are not making any sense, he just throws aerodynamic
terms around and invents new ones such as "slip layer" that nobody
else has ever observed. How the deturbulator "detaches" the boundary
layer from the surface is a mystery and left to future generations of
physicists to explore.

The whole story reminds me actually of the Cold Fusion hype in the
early 90's: a desirable effect is found and described without
theoretical underpinning. In this case, the effect is found only on
one glider, Jim Hendrix' Cirrus and only in a small airspeed window,
make that exactly 51 knots. We are told that more research is needed
before other gliders can be blessed with this "textured tape
Deturbulator". Again, I'm skeptical by nature and this all just
smells of Voodoo science. The claimed L/D that "peaked" at 70 to 120
to 1 (Collum article) at least I can explain: over short distances in
convective air all our gliders reach those numbers. Hell, I flew last
weekend over 66 miles at an L/D of 125 without circling and at 90mph,
according to SeeYou. Maybe the reason is that I dumped my pee-bag out
the side window before that run and the hyper-viscous fluid affected
the drag of fuselage and empennage, who knows!?

This all is right now of no practical use to us. I could run all day
in Jim's Cirrus at 51 knots and still not make good speed going x-
country. In fact I would guess I spend about 30 seconds at that speed
on a typical 3 hour flight. Sorry for being so negative but again,
please show me the underlying effect. Saying we don't know right now
doesn't cut it. Come back when you can explain what you believe you
measured.
If this 'revolutionary' improvement is for real, Dr. Sinha will
shortly be a very rich man. Until then, good luck. His patent
application is pending and if you google the subject you will find
that nobody but the inventor has published on this subject. One would
guess that the aerodynamicists of the world would beat a path to his
door if they believed this to work.

As far as I understand the claim is that the deturbulator reduces the wings
profile drag, and there is no effect on any other component of aircraft
total drag like induced drag, fuselage and empennage drag, interference drag
etc...

I would like to see an overview of the drag components of an unmodified
Standard Cirrus at 51kts. Then we could discuss how much reduction of
profile drag alone would be necessary to achieve the L/D ratios of 45, 70
and even 100 claimed by Jim Hendrix in postings to this thread.

Please note that I do not rule out that deturbulators (or this specific
deturbulator) might have positive effects on profile drag, but I strongly
doubt the measurement methods used and conclusions drawn from these.

Michael

Whether or not anything comes of the research, the post is interesting and
a lot more enjoyable to read about than what brand of wheel bearing works
best in glider trailers etc. I think most of us follow the story with
interest and wish he and Dr. Sinha well.

I received an email from Dick Johnson about a month ago on another subject
and he wrote "Maybe Deturbulators on the wing top surfaces, and
Turbulators on the wing bottom surfaces will be the next step?" So not
all the experts are completely shunning the deturbulator.

Brian Bange


Am I the only one who is completely underwhelmed by this "exiting"
news that comes well timed after the June article in SSA magazine by
Bill Collum? Is anybody able to explain to me even in basic terms
what the physics behind the claimed effect are? Mr. Collums
explanations are not making any sense, he just throws aerodynamic
terms around and invents new ones such as "slip layer" that nobody
else has ever observed. How the deturbulator "detaches" the boundary
layer from the surface is a mystery and left to future generations of
physicists to explore.

The whole story reminds me actually of the Cold Fusion hype in the
early 90's: a desirable effect is found and described without
theoretical underpinning. In this case, the effect is found only on
one glider, Jim Hendrix' Cirrus and only in a small airspeed window,
make that exactly 51 knots. We are told that more research is needed
before other gliders can be blessed with this "textured tape
Deturbulator". Again, I'm skeptical by nature and this all just
smells of Voodoo science. The claimed L/D that "peaked" at 70 to 120
to 1 (Collum article) at least I can explain: over short distances in
convective air all our gliders reach those numbers. Hell, I flew last
weekend over 66 miles at an L/D of 125 without circling and at 90mph,
according to SeeYou. Maybe the reason is that I dumped my pee-bag out
the side window before that run and the hyper-viscous fluid affected
the drag of fuselage and empennage, who knows!?

This all is right now of no practical use to us. I could run all day
in Jim's Cirrus at 51 knots and still not make good speed going x-
country. In fact I would guess I spend about 30 seconds at that speed
on a typical 3 hour flight. Sorry for being so negative but again,
please show me the underlying effect. Saying we don't know right now
doesn't cut it. Come back when you can explain what you believe you
measured.
If this 'revolutionary' improvement is for real, Dr. Sinha will
shortly be a very rich man. Until then, good luck. His patent
application is pending and if you google the subject you will find
that nobody but the inventor has published on this subject. One would
guess that the aerodynamicists of the world would beat a path to his
door if they believed this to work.

You guys are doing great R&D and have found something worth
investigating.

I know that everyone would buy a set of "Tapes" that would improve
their L/D 20%

I know a sailplane designer/manufacturer would jump at the chance to
improve performance that much these days
and I am sure there is activity on this we are not aware of in other
sectors as well.

Looking forward to seeing where this discovery takes us.

Be patient or offer to help if you can not stand the wait.

Ray

Brian,

Bottom and top surface deturbulators has been a subject of discussion
between Sumon and me for a few years. He was against the idea for reasons
that were hard for me to grasp. But, later, when I did extensive oil flow
visualizations to find out why the present deturbulators were not working,
on a lark, I put oil on the bottom surfaces just to see if the transition
bubble was still there. I was shocked to see that the entire bottom wing
surface had the same non-streamed, mottled oil blotches as on the top
surface (and no hint of a bubble). Even without deturbulators, the bottom
surface was reaping the benefits of the leading edge tape step-down and (I
suppose) the modified flow pattern on the upper surface. At any rate, the
oil flows are clear and I wonder what would be achieved by altering
something so perfect?

BTW, I have a large number of these oil flow images at two speeds, 50 KIA
and 80 KIA. I plan to post them all with my interpretations when I get
the time.

Regards,
JEH

At 13:28 10 June 2008, Brian Bange wrote:
Whether or not anything comes of the research, the post is interesting
and
a lot more enjoyable to read about than what brand of wheel bearing
works
best in glider trailers etc. I think most of us follow the story with
interest and wish he and Dr. Sinha well.

I received an email from Dick Johnson about a month ago on another
subject
and he wrote "Maybe Deturbulators on the wing top surfaces, and
Turbulators on the wing bottom surfaces will be the next step?" So not
all the experts are completely shunning the deturbulator.

Brian Bange


Am I the only one who is completely underwhelmed by this "exiting"
news that comes well timed after the June article in SSA magazine by
Bill Collum? Is anybody able to explain to me even in basic terms
what the physics behind the claimed effect are? Mr. Collums
explanations are not making any sense, he just throws aerodynamic
terms around and invents new ones such as "slip layer" that nobody
else has ever observed. How the deturbulator "detaches" the boundary
layer from the surface is a mystery and left to future generations of
physicists to explore.

The whole story reminds me actually of the Cold Fusion hype in the
early 90's: a desirable effect is found and described without
theoretical underpinning. In this case, the effect is found only on
one glider, Jim Hendrix' Cirrus and only in a small airspeed window,
make that exactly 51 knots. We are told that more research is needed
before other gliders can be blessed with this "textured tape
Deturbulator". Again, I'm skeptical by nature and this all just
smells of Voodoo science. The claimed L/D that "peaked" at 70 to 120
to 1 (Collum article) at least I can explain: over short distances in
convective air all our gliders reach those numbers. Hell, I flew last
weekend over 66 miles at an L/D of 125 without circling and at 90mph,
according to SeeYou. Maybe the reason is that I dumped my pee-bag out
the side window before that run and the hyper-viscous fluid affected
the drag of fuselage and empennage, who knows!?

This all is right now of no practical use to us. I could run all day
in Jim's Cirrus at 51 knots and still not make good speed going x-
country. In fact I would guess I spend about 30 seconds at that speed
on a typical 3 hour flight. Sorry for being so negative but again,
please show me the underlying effect. Saying we don't know right now
doesn't cut it. Come back when you can explain what you believe you
measured.
If this 'revolutionary' improvement is for real, Dr. Sinha will
shortly be a very rich man. Until then, good luck. His patent
application is pending and if you google the subject you will find
that nobody but the inventor has published on this subject. One would
guess that the aerodynamicists of the world would beat a path to his
door if they believed this to work.

Am I the only one who is completely underwhelmed by this "exiting"
news that comes well timed after the June article in SSA magazine by
Bill Collum? Is anybody able to explain to me even in basic terms
what the physics behind the claimed effect are? Mr. Collums
explanations are not making any sense, he just throws aerodynamic
terms around and invents new ones such as "slip layer" that nobody
else has ever observed. How the deturbulator "detaches" the boundary
layer from the surface is a mystery and left to future generations of
physicists to explore.

I'm not an aerodynamicist (and I'm not lecturing :-), but as I
understand it, the deturbulators work something like this. On a normal
(non deturbulated) wing, where the laminar separation occurs, there is
a major change in the airflow so it can get up and over the dynamic
obstacle the turbulence on the wing poses to the flow air . This
action of air flowing up and over the turbulent layer IS for all
intents and purposes assuming the shape of a completely new (and
undesirable) airfoil. What the deturbulators attempt to do is to tame
this turbulent layer, sculpting it into a more USEFUL aerodynamically
shaped interference by vibrating at certain frequencies to manipulate
the shape/size/location of this layer. From what I understand, the
individual deturbulator panels essentially flutter at the correct
frequencies to effect this change at certain speeds, which in this
early proof of concept tests seems to be around 51kts IAS.

Again, I'm skeptical by nature and this all just
smells of Voodoo science. The claimed L/D that "peaked" at 70 to 120
to 1 (Collum article) at least I can explain: over short distances in
convective air all our gliders reach those numbers. Hell, I flew last
weekend over 66 miles at an L/D of 125 without circling and at 90mph,
according to SeeYou. Maybe the reason is that I dumped my pee-bag out
the side window before that run and the hyper-viscous fluid affected
the drag of fuselage and empennage, who knows!?

That is why tests are being conducted where the modified Cirrus is
being flown wingtip to wingtip with gliders of KNOWN performances, to
eliminate the effects imparted on performance due to airmass
variations.

This all is right now of no practical use to us. I could run all day
in Jim's Cirrus at 51 knots and still not make good speed going x-
country. In fact I would guess I spend about 30 seconds at that speed
on a typical 3 hour flight. Sorry for being so negative but again,
please show me the underlying effect. Saying we don't know right now
doesn't cut it. Come back when you can explain what you believe you
measured.

Historically, you will find many great contributions that began as
novelty ideas that appeared to the layman to have no practical value
and received much scoffing etc too. Perhaps the deturbulators will go
nowhere, or perhaps they may be the foundation of future aerodynamics.
I am glad someone is else dong the research to find out, that way I
can just fly, and perhaps benefit from this in the future.

Paul

wrote:



Jim, Interesting stuff. For the reasons stated previously
that the
flight envelope of comparison favors the Std. Cirrus and not
necessarily the Diana, is there a plan to do a comparison
between a
detubulated Std. Cirrus vs another random 38yr old Std.
Cirrus?

Isn't the Dick Johnson flight comparison using the same glider
with and without deturbulators the same thing? Perhaps better.
Dick's careful testing and conclusions have done more than
anything else to lend credibility, at least for me.

I would like to see more Johnson-style testing performed on
different glider types. Seems like to-date all glider data is
hinhes on this sole Standard Cirrus.
--
-Doug

** Posted from http://www.teranews.com **

Jim, Interesting stuff. For the reasons stated previously that the
flight envelope of comparison favors the Std. Cirrus and not
necessarily the Diana, is there a plan to do a comparison between a
detubulated Std. Cirrus vs another random 38yr old Std. Cirrus?

At 18:24 10 June 2008, wrote:
Jim, Interesting stuff. For the reasons stated previously that the
flight envelope of comparison favors the Std. Cirrus and not
necessarily the Diana, is there a plan to do a comparison between a
detubulated Std. Cirrus vs another random 38yr old Std. Cirrus?





I addressed the question of the differnce in best speeds of the two
aircraft earlier and concluded that it is essentially negligible.

However, in fact, all things permitting, I will try a Std. Cirrus vs. Std.
Cirrus flight this Saturday. The other aircraft is owned by Jim Maye. It
is serial number 30, whereas mine is #60. That is significant because
around #150 Klaus Holidhaus gave the wing an additional .75 degree twist.
Both gliders in the planned test will be the same. Both pilots too are...
ahum...well fed.

The main reason for this test is that people like to see differences
directly rather than implied. So, I am expecting to see #30 sinking
relative to #60. Then the problem will be that we will no longer be
flying in the same air and we will need to restart the test. So we may
have a series of short runs. I hope so at least.

If you don't hear from me early next week, it will mean that something
prevented the test, or it didn't work out as expected and I'm stalling
for time to figure it out and/or stage another engagement. I much prefer
reporting our successes than failures.

JEH