deturbulated std cirrus flies against Diana 1

At 08:57 10 June 2008, Matt Herron Jr. wrote:
Umm...

What happened to the wind tunnel testing that was underway over four
years ago? This is where experimentation that requires such tight
control of parameters and is so sensitive to humidity, turbulence,
etc. should be conducted. If this research looked so promising and
was funded by NASA, they have rather lovely tunnels you could put the
whole Cirrus into if you wished. I would think that performance
questions could be answered in a matter of a month or two. What went
wrong there?

I am the first to consider that new breakthroughs are almost always
met with significant criticism, so I like to fall back on the facts
whenever possible. As a sanity check, lets look at the latest
comparison flight between the Cirrus @ the claimed 33.5:1 glide ratio
and the Dana 1 at 45:1 On one leg that was graphed, the flight lasted
8 minutes with the two aircraft flying side by side at about 51
knots. It looks like the Cirrus kept up quite nicely with the Dana!

But lets take a closer look. At 51 knots, that's about 5164 ft/minute
forward, and for the Dana, about 114 ft/minute sink in still air.
Over the course of the 8 minutes, the Dana should sink 918 ft, and the
Cirrus, 1233 ft, so the expected difference in altitude is about 315
ft after 8 minutes of flying. From the trace, both aircraft only sink
about 100 feet over this time, and are flying through sink and lift
the whole time of strengths up to 4 knots. So one could say that the
variation in altitude contributed by the still air sink rate of the
gliders is only about 25% of the total. The other 75% is due to
flying through rising and sinking air. Given that the gliders were
flying side by side through slightly different air, is it possible
that any performance variations (good or bad) were completely masked
by minor variances in this more dominant variable of moving air
masses? It would take an average difference of only 0.37 knots of
lift/sink over the flight to account for this.

I would like to think it's all true, but so far have little basis
other than hope. Get back in the wind tunnel, or show me a 40 minute
final glide at 7:am in still air.

Matt

Matt,

Notice how the two aircraft match each other bounce for bounce in both
flight legs, especially on the-upwind, cloud-street run. This shows that
the aircraft were close enough to be seeing essentially the same air. In
fact, we did another, shorter out and return but I did not post that one,
because it was clear that the Diana was not matching my "bumps." In
fact it lost altitude to my glider, but it was clear that the Diana was
too far away.

Both flight logs are on the web for you to download. Evidently you looked
at them. But I would just like to make the point to everyone that I am not
making claims here, I am throwing data at you to deal with. It is what it
is!

Thank you, Mark, for making an honest effort to deal with the facts.

JEH

"Jim Hendrix" wrote in message
...
At 04:04 10 June 2008, Ramy wrote:
On Jun 9, 5:13=A0pm, Jim Hendrix wrote:
...
Looks like the results speak for themselves and it sounds promissing.
But why does it take so long to turn it into production? According to
the web site the experiments started at 2003 and so far it was only
tested on a standard cirrus. How longer will it take until I can have
it on my 27?

Ramy

Ramy,

To be brutally frank, it's taking a long time to develop this technology
because neither Sumon nor I are very disciplined in our methods and a
great deal of hard work remains to fully understand both the flow-surface
interaction of the deturbulator device and the overall wing aerodynamics
we are achieving with it.

Sumon knows what he wants to achieve, but we are dealing with subtleties
that extend well beyond his original concept, which were close enough to
work but not really on target. I've watched his concepts morph over time
regarding both the flow-surface interaction and the wing aerodynamics
model. We now have a third person loosely associated with the project to
model the flow-surface interaction using his LINFLOW software package,
Jari Hyvärinen of ANKER-ZEMER Engineering AB in Norway.

The slowness comes down to manpower issues. Sumon is almost completely
committed to developing a deturbulator product for semi tractor trailer
rigs. As he makes improvements in the trucking device, I occasionally
divert his attention long enough to upgrade the deturbulators on my
glider. Thus, for example, we now seem to have something that sometimes
works even in the summer months, if the humidity is not too great. So the
main thrust of his attention is directed toward a, technically easier and
more lucrative, market. For my part, I have higher priorities, so the
deturbulator sort of fills in the cracks. Also, I don't have the
aerodynamics background for the fundamental work that needs to be done;
that will wait until the aerodynamics community sees the light and begins
doing the work, or large corporations pony up the funds for R&D projects.
Like me, Jari Hyvärinen needs to make a living with his normal engineering
consulting work, so for him too this is not a main priority.

Add to that the enormous amount of research and engineering that remains
to be done to fully understand the modes of flow-surface interaction that
can occur, those can be exploited for specific aims and those that must be
avoided (both are well demonstrated in Johnson's 2006 test flights-
http://sinhatech.com/SinhaFCSD-Progr...on-Details.asp) and you can
see that we have a bottle neck that is restricting progress. The sooner
the aerodynamics community takes this seriously, the sooner we will get
there. For my part, I intend to keep collecting data until the sheer
weight of it becomes undeniable. At this point in time, I am only
interested in demonstrating the concept. Producing a viable product for
use in aviation is a long term proposition, requiring real, disciplined
R&D work and funding.

The problem with treating other glider wings is that each wing is a unique
problem that has to be studied, then tested iteratively, making
adjustments
to the configuration to arrive at something what works. The process was
started with Greg Cole's Sparrowhawk, but the first attempt failed due
largely to poor quality control of the deturbulator itself (a problem that
I think will be solved with the next application on my glider) and the
project was not pursued to the point of success. My own experience, after
Johnson tested my glider in December 2006, was two failures before the
present application. And even this application was not up to par and had
to be studied with oil flow visualizations to see what the problem was. I
finally had to remove some intermediate tapes that were needed for the
Johnson deturbulators and also smooth the sharp leading edge of the new
deturbulators with (get this) Scotch tape. Finally, the first flight
after those modifications essentially reproduced Johnson's remarkable
third flight in 2006. Bottom line, it takes a lot of work and persistence
to realize success and there is too little Sinha to go around...he's a
bottle neck.

Sorry, but reality is reality!
JEH

I hope this research keeps going since it's about the most interesting area
of glider aerodynamics currently. Give these guys some credit. This is
difficult work.

Even after more than 100 years of practical aerodynamics, there are still
mysteries in extreme near field boundary layer behavior to be discovered but
there are few working in the field since the big money is interested in much
higher Reynolds numbers.

Wind tunnel data would be interesting but one suspects the deturbulator is
extremely sensitive to micro turbulence embedded in the flow. There aren't
too may extremely low turbulence wind tunnels in the Reynolds number range
of interest. Even if this were done, there would be the objection that the
data were just "laboratory results" that still had to be 'proved' in the
real world. In flight testing has it's place and it's cheaper.

What would be interesting to me would be some measurements from a static
pressure array (drag rake) behind the TE to see what changes are caused by
the deturbulator.

At 14:28 10 June 2008, Bill Daniels wrote:

"Jim Hendrix" wrote in message
...
At 04:04 10 June 2008, Ramy wrote:
On Jun 9, 5:13=A0pm, Jim Hendrix wrote:
...
Looks like the results speak for themselves and it sounds promissing.
But why does it take so long to turn it into production? According to
the web site the experiments started at 2003 and so far it was only
tested on a standard cirrus. How longer will it take until I can have
it on my 27?

Ramy

Ramy,

To be brutally frank, it's taking a long time to develop this
technology
because neither Sumon nor I are very disciplined in our methods and a
great deal of hard work remains to fully understand both the
flow-surface
interaction of the deturbulator device and the overall wing
aerodynamics
we are achieving with it.

Sumon knows what he wants to achieve, but we are dealing with
subtleties
that extend well beyond his original concept, which were close enough
to
work but not really on target. I've watched his concepts morph over
time
regarding both the flow-surface interaction and the wing aerodynamics
model. We now have a third person loosely associated with the project
to
model the flow-surface interaction using his LINFLOW software package,
Jari Hyvärinen of ANKER-ZEMER Engineering AB in Norway.

The slowness comes down to manpower issues. Sumon is almost
completely
committed to developing a deturbulator product for semi tractor
trailer
rigs. As he makes improvements in the trucking device, I occasionally
divert his attention long enough to upgrade the deturbulators on my
glider. Thus, for example, we now seem to have something that
sometimes
works even in the summer months, if the humidity is not too great. So
the
main thrust of his attention is directed toward a, technically easier
and
more lucrative, market. For my part, I have higher priorities, so the
deturbulator sort of fills in the cracks. Also, I don't have the
aerodynamics background for the fundamental work that needs to be
done;
that will wait until the aerodynamics community sees the light and
begins
doing the work, or large corporations pony up the funds for R&D
projects.
Like me, Jari Hyvärinen needs to make a living with his normal
engineering
consulting work, so for him too this is not a main priority.

Add to that the enormous amount of research and engineering that
remains
to be done to fully understand the modes of flow-surface interaction
that
can occur, those can be exploited for specific aims and those that
must
be
avoided (both are well demonstrated in Johnson's 2006 test flights-
http://sinhatech.com/SinhaFCSD-Progr...on-Details.asp) and you
can
see that we have a bottle neck that is restricting progress. The
sooner
the aerodynamics community takes this seriously, the sooner we will
get
there. For my part, I intend to keep collecting data until the sheer
weight of it becomes undeniable. At this point in time, I am only
interested in demonstrating the concept. Producing a viable product
for
use in aviation is a long term proposition, requiring real,
disciplined
R&D work and funding.

The problem with treating other glider wings is that each wing is a
unique
problem that has to be studied, then tested iteratively, making
adjustments
to the configuration to arrive at something what works. The process
was
started with Greg Cole's Sparrowhawk, but the first attempt failed
due
largely to poor quality control of the deturbulator itself (a problem
that
I think will be solved with the next application on my glider) and the
project was not pursued to the point of success. My own experience,
after
Johnson tested my glider in December 2006, was two failures before the
present application. And even this application was not up to par and
had
to be studied with oil flow visualizations to see what the problem was.

I
finally had to remove some intermediate tapes that were needed for the
Johnson deturbulators and also smooth the sharp leading edge of the
new
deturbulators with (get this) Scotch tape. Finally, the first flight
after those modifications essentially reproduced Johnson's remarkable
third flight in 2006. Bottom line, it takes a lot of work and
persistence
to realize success and there is too little Sinha to go around...he's
a
bottle neck.

Sorry, but reality is reality!
JEH

I hope this research keeps going since it's about the most interesting
area
of glider aerodynamics currently. Give these guys some credit. This is

difficult work.

Even after more than 100 years of practical aerodynamics, there are still

mysteries in extreme near field boundary layer behavior to be discovered
but
there are few working in the field since the big money is interested in
much
higher Reynolds numbers.

Wind tunnel data would be interesting but one suspects the deturbulator
is

extremely sensitive to micro turbulence embedded in the flow. There
aren't
too may extremely low turbulence wind tunnels in the Reynolds number
range

of interest. Even if this were done, there would be the objection that
the
data were just "laboratory results" that still had to be 'proved' in
the
real world. In flight testing has it's place and it's cheaper.

What would be interesting to me would be some measurements from a static

pressure array (drag rake) behind the TE to see what changes are caused
by

the deturbulator.



Sumon has taken data with a chord high drag probe, that I built for him,
in his 9" x 12" wind tunnel. The problem is that the data doesn't
scale very well from such a small tunnel. The deturbulater effects are
greatly exagerated. Nevertheless, it works for screening ideas before
trying them full scale in our "big tunnel."

JEH

"Jim Hendrix" wrote in message
...
At 14:28 10 June 2008, Bill Daniels wrote:

"Jim Hendrix" wrote in message
...
At 04:04 10 June 2008, Ramy wrote:
On Jun 9, 5:13=A0pm, Jim Hendrix wrote:
...
Looks like the results speak for themselves and it sounds promissing.
But why does it take so long to turn it into production? According to
the web site the experiments started at 2003 and so far it was only
tested on a standard cirrus. How longer will it take until I can have
it on my 27?

Ramy

Ramy,

To be brutally frank, it's taking a long time to develop this
technology
because neither Sumon nor I are very disciplined in our methods and a
great deal of hard work remains to fully understand both the
flow-surface
interaction of the deturbulator device and the overall wing
aerodynamics
we are achieving with it.

Sumon knows what he wants to achieve, but we are dealing with
subtleties
that extend well beyond his original concept, which were close enough
to
work but not really on target. I've watched his concepts morph over
time
regarding both the flow-surface interaction and the wing aerodynamics
model. We now have a third person loosely associated with the project
to
model the flow-surface interaction using his LINFLOW software package,
Jari Hyvärinen of ANKER-ZEMER Engineering AB in Norway.

The slowness comes down to manpower issues. Sumon is almost
completely
committed to developing a deturbulator product for semi tractor
trailer
rigs. As he makes improvements in the trucking device, I occasionally
divert his attention long enough to upgrade the deturbulators on my
glider. Thus, for example, we now seem to have something that
sometimes
works even in the summer months, if the humidity is not too great. So
the
main thrust of his attention is directed toward a, technically easier
and
more lucrative, market. For my part, I have higher priorities, so the
deturbulator sort of fills in the cracks. Also, I don't have the
aerodynamics background for the fundamental work that needs to be
done;
that will wait until the aerodynamics community sees the light and
begins
doing the work, or large corporations pony up the funds for R&D
projects.
Like me, Jari Hyvärinen needs to make a living with his normal
engineering
consulting work, so for him too this is not a main priority.

Add to that the enormous amount of research and engineering that
remains
to be done to fully understand the modes of flow-surface interaction
that
can occur, those can be exploited for specific aims and those that
must
be
avoided (both are well demonstrated in Johnson's 2006 test flights-
http://sinhatech.com/SinhaFCSD-Progr...on-Details.asp) and you
can
see that we have a bottle neck that is restricting progress. The
sooner
the aerodynamics community takes this seriously, the sooner we will
get
there. For my part, I intend to keep collecting data until the sheer
weight of it becomes undeniable. At this point in time, I am only
interested in demonstrating the concept. Producing a viable product
for
use in aviation is a long term proposition, requiring real,
disciplined
R&D work and funding.

The problem with treating other glider wings is that each wing is a
unique
problem that has to be studied, then tested iteratively, making
adjustments
to the configuration to arrive at something what works. The process
was
started with Greg Cole's Sparrowhawk, but the first attempt failed
due
largely to poor quality control of the deturbulator itself (a problem
that
I think will be solved with the next application on my glider) and the
project was not pursued to the point of success. My own experience,
after
Johnson tested my glider in December 2006, was two failures before the
present application. And even this application was not up to par and
had
to be studied with oil flow visualizations to see what the problem was.

I
finally had to remove some intermediate tapes that were needed for the
Johnson deturbulators and also smooth the sharp leading edge of the
new
deturbulators with (get this) Scotch tape. Finally, the first flight
after those modifications essentially reproduced Johnson's remarkable
third flight in 2006. Bottom line, it takes a lot of work and
persistence
to realize success and there is too little Sinha to go around...he's
a
bottle neck.

Sorry, but reality is reality!
JEH

I hope this research keeps going since it's about the most interesting
area
of glider aerodynamics currently. Give these guys some credit. This is

difficult work.

Even after more than 100 years of practical aerodynamics, there are still

mysteries in extreme near field boundary layer behavior to be discovered
but
there are few working in the field since the big money is interested in
much
higher Reynolds numbers.

Wind tunnel data would be interesting but one suspects the deturbulator
is

extremely sensitive to micro turbulence embedded in the flow. There
aren't
too may extremely low turbulence wind tunnels in the Reynolds number
range

of interest. Even if this were done, there would be the objection that
the
data were just "laboratory results" that still had to be 'proved' in
the
real world. In flight testing has it's place and it's cheaper.

What would be interesting to me would be some measurements from a static

pressure array (drag rake) behind the TE to see what changes are caused
by

the deturbulator.



Sumon has taken data with a chord high drag probe, that I built for him,
in his 9" x 12" wind tunnel. The problem is that the data doesn't
scale very well from such a small tunnel. The deturbulater effects are
greatly exagerated. Nevertheless, it works for screening ideas before
trying them full scale in our "big tunnel."

JEH

"Chord high drag probe"? You mean like a meter high? Thatsa big probe!
You may have meant wing thickness high probe. Anyway, put that thing on the
Cirrus and get before and after in-flight data. That would be more
convincing than comparison glides, at least to me.

Mount a video camera focused on the ASI, Altimeter and a clock. Put a tiny
pager vibrator motor on the instruments to keep them from sticking. It's
old fashoned but it works.

Is there a big, low activity runway near you where you could do auto tows at
the crack of dawn?
Auto tows are cheap and even if you only get one data point per tow, they're
worthwhile.

The California dry lakes are (naturally) in desert basins where cold air
collects at night. There's often an isothermal layer up to more than 1000'
AGL by dawn so the air below the inversion is DEAD STILL until about an hour
or so after sun up - great places to get reliable speed vs sink flight test
numbers. If you plotted sink rate vs altitude at a constant airspeed, it
would be a straight line until about 50' AGL where ground effects would
start to show up.

I remember doing some tests where we would tow back and forth across the El
Mirage dry lake. The tow car would be the "chase plane" with a movie camera
and follow the glider until it landed at the far side of the dry lake.
Then, we'd spin it around and tow it back the other direction. We could get
in a dozen flights before the first turbulence was noticed. This would fill
in the low end of the polar curve in just one morning.

Bill D

At 22:21 10 June 2008, Bill Daniels wrote:

"Jim Hendrix" wrote in message
...
At 14:28 10 June 2008, Bill Daniels wrote:

"Jim Hendrix" wrote in message
...
At 04:04 10 June 2008, Ramy wrote:
On Jun 9, 5:13=A0pm, Jim Hendrix wrote:
...
Looks like the results speak for themselves and it sounds
promissing.
But why does it take so long to turn it into production? According
to
the web site the experiments started at 2003 and so far it was only
tested on a standard cirrus. How longer will it take until I can
have
it on my 27?

Ramy

Ramy,

To be brutally frank, it's taking a long time to develop this
technology
because neither Sumon nor I are very disciplined in our methods and
a
great deal of hard work remains to fully understand both the
flow-surface
interaction of the deturbulator device and the overall wing
aerodynamics
we are achieving with it.

Sumon knows what he wants to achieve, but we are dealing with
subtleties
that extend well beyond his original concept, which were close
enough
to
work but not really on target. I've watched his concepts morph
over
time
regarding both the flow-surface interaction and the wing
aerodynamics
model. We now have a third person loosely associated with the
project
to
model the flow-surface interaction using his LINFLOW software
package,
Jari Hyvärinen of ANKER-ZEMER Engineering AB in Norway.

The slowness comes down to manpower issues. Sumon is almost
completely
committed to developing a deturbulator product for semi tractor
trailer
rigs. As he makes improvements in the trucking device, I
occasionally
divert his attention long enough to upgrade the deturbulators on my
glider. Thus, for example, we now seem to have something that
sometimes
works even in the summer months, if the humidity is not too great.
So
the
main thrust of his attention is directed toward a, technically
easier
and
more lucrative, market. For my part, I have higher priorities, so
the
deturbulator sort of fills in the cracks. Also, I don't have the
aerodynamics background for the fundamental work that needs to be
done;
that will wait until the aerodynamics community sees the light and
begins
doing the work, or large corporations pony up the funds for R&D
projects.
Like me, Jari Hyvärinen needs to make a living with his normal
engineering
consulting work, so for him too this is not a main priority.

Add to that the enormous amount of research and engineering that
remains
to be done to fully understand the modes of flow-surface interaction
that
can occur, those can be exploited for specific aims and those that
must
be
avoided (both are well demonstrated in Johnson's 2006 test flights-
http://sinhatech.com/SinhaFCSD-Progr...on-Details.asp) and you
can
see that we have a bottle neck that is restricting progress. The
sooner
the aerodynamics community takes this seriously, the sooner we will
get
there. For my part, I intend to keep collecting data until the
sheer
weight of it becomes undeniable. At this point in time, I am only
interested in demonstrating the concept. Producing a viable product
for
use in aviation is a long term proposition, requiring real,
disciplined
R&D work and funding.

The problem with treating other glider wings is that each wing is a
unique
problem that has to be studied, then tested iteratively, making
adjustments
to the configuration to arrive at something what works. The process
was
started with Greg Cole's Sparrowhawk, but the first attempt failed
due
largely to poor quality control of the deturbulator itself (a
problem
that
I think will be solved with the next application on my glider) and
the
project was not pursued to the point of success. My own experience,
after
Johnson tested my glider in December 2006, was two failures before
the
present application. And even this application was not up to par
and
had
to be studied with oil flow visualizations to see what the problem
was.

I
finally had to remove some intermediate tapes that were needed for
the
Johnson deturbulators and also smooth the sharp leading edge of the
new
deturbulators with (get this) Scotch tape. Finally, the first
flight
after those modifications essentially reproduced Johnson's
remarkable
third flight in 2006. Bottom line, it takes a lot of work and
persistence
to realize success and there is too little Sinha to go
around...he's
a
bottle neck.

Sorry, but reality is reality!
JEH

I hope this research keeps going since it's about the most
interesting
area
of glider aerodynamics currently. Give these guys some credit. This
is

difficult work.

Even after more than 100 years of practical aerodynamics, there are
still

mysteries in extreme near field boundary layer behavior to be
discovered
but
there are few working in the field since the big money is interested
in
much
higher Reynolds numbers.

Wind tunnel data would be interesting but one suspects the
deturbulator
is

extremely sensitive to micro turbulence embedded in the flow. There
aren't
too may extremely low turbulence wind tunnels in the Reynolds number
range

of interest. Even if this were done, there would be the objection
that
the
data were just "laboratory results" that still had to be 'proved'
in
the
real world. In flight testing has it's place and it's cheaper.

What would be interesting to me would be some measurements from a
static

pressure array (drag rake) behind the TE to see what changes are
caused
by

the deturbulator.



Sumon has taken data with a chord high drag probe, that I built for
him,
in his 9" x 12" wind tunnel. The problem is that the data doesn't
scale very well from such a small tunnel. The deturbulater effects
are
greatly exagerated. Nevertheless, it works for screening ideas before
trying them full scale in our "big tunnel."

JEH

"Chord high drag probe"? You mean like a meter high? Thatsa big
probe!
You may have meant wing thickness high probe. Anyway, put that thing on
the
Cirrus and get before and after in-flight data. That would be more
convincing than comparison glides, at least to me.

Mount a video camera focused on the ASI, Altimeter and a clock. Put a
tiny
pager vibrator motor on the instruments to keep them from sticking.
It's
old fashoned but it works.

Is there a big, low activity runway near you where you could do auto
tows
at
the crack of dawn?
Auto tows are cheap and even if you only get one data point per tow,
they're
worthwhile.

The California dry lakes are (naturally) in desert basins where cold air

collects at night. There's often an isothermal layer up to more than
1000'
AGL by dawn so the air below the inversion is DEAD STILL until about an
hour
or so after sun up - great places to get reliable speed vs sink flight
test
numbers. If you plotted sink rate vs altitude at a constant airspeed, it

would be a straight line until about 50' AGL where ground effects would

start to show up.

I remember doing some tests where we would tow back and forth across the
El
Mirage dry lake. The tow car would be the "chase plane" with a movie
camera
and follow the glider until it landed at the far side of the dry lake.
Then, we'd spin it around and tow it back the other direction. We
could
get
in a dozen flights before the first turbulence was noticed. This would
fill
in the low end of the polar curve in just one morning.

Bill D



bill,

The chord high probe is 5" long and was used with 5" chord wing sections
in the Sinha wind tunnel. There is a page on Sinha's wind tunnel on his
web site.

Aircraft performance is the bottom line. Parallel flying is a cheaper and
quicker way to get relults because both gliders are seeing the same air
movement. You can see this clearly in the Diana data. For a truly
accurate test you need pristine air, but it's the wrong season for that
and a 10,000' tow cost me $119, not the mention the cost of gasoline for
5 hours on the road. So, instead, I opted for 20 minutes of real world
formation flying.

Besides that, the optimal capabilities of a glider mean less than how it
will actually perform in normal turbulence. So I want to know how much of
that narrow performance speed peak I can realize under real soaring
conditions. At this point, it looks like I lose about half of the peak
capabilities of the deturbulator as I analyze the log data from Johnson's
testing. Johnson's measurement over 4 minutes (that's how long it took
to lose 400 feet) averaged out to 64:1 (Dick threw that flight out of his
analysis that gave 18% improvement), so from there I'm losing about one
third. This will become clearer as the data keep coming in.

JEH

At 22:21 10 June 2008, Bill Daniels wrote:

"Jim Hendrix" wrote in message
...
At 14:28 10 June 2008, Bill Daniels wrote:

"Jim Hendrix" wrote in message
...
At 04:04 10 June 2008, Ramy wrote:
On Jun 9, 5:13=A0pm, Jim Hendrix wrote:
...
Looks like the results speak for themselves and it sounds
promissing.
But why does it take so long to turn it into production? According
to
the web site the experiments started at 2003 and so far it was only
tested on a standard cirrus. How longer will it take until I can
have
it on my 27?

Ramy

Ramy,

To be brutally frank, it's taking a long time to develop this
technology
because neither Sumon nor I are very disciplined in our methods and
a
great deal of hard work remains to fully understand both the
flow-surface
interaction of the deturbulator device and the overall wing
aerodynamics
we are achieving with it.

Sumon knows what he wants to achieve, but we are dealing with
subtleties
that extend well beyond his original concept, which were close
enough
to
work but not really on target. I've watched his concepts morph
over
time
regarding both the flow-surface interaction and the wing
aerodynamics
model. We now have a third person loosely associated with the
project
to
model the flow-surface interaction using his LINFLOW software
package,
Jari Hyvärinen of ANKER-ZEMER Engineering AB in Norway.

The slowness comes down to manpower issues. Sumon is almost
completely
committed to developing a deturbulator product for semi tractor
trailer
rigs. As he makes improvements in the trucking device, I
occasionally
divert his attention long enough to upgrade the deturbulators on my
glider. Thus, for example, we now seem to have something that
sometimes
works even in the summer months, if the humidity is not too great.
So
the
main thrust of his attention is directed toward a, technically
easier
and
more lucrative, market. For my part, I have higher priorities, so
the
deturbulator sort of fills in the cracks. Also, I don't have the
aerodynamics background for the fundamental work that needs to be
done;
that will wait until the aerodynamics community sees the light and
begins
doing the work, or large corporations pony up the funds for R&D
projects.
Like me, Jari Hyvärinen needs to make a living with his normal
engineering
consulting work, so for him too this is not a main priority.

Add to that the enormous amount of research and engineering that
remains
to be done to fully understand the modes of flow-surface interaction
that
can occur, those can be exploited for specific aims and those that
must
be
avoided (both are well demonstrated in Johnson's 2006 test flights-
http://sinhatech.com/SinhaFCSD-Progr...on-Details.asp) and you
can
see that we have a bottle neck that is restricting progress. The
sooner
the aerodynamics community takes this seriously, the sooner we will
get
there. For my part, I intend to keep collecting data until the
sheer
weight of it becomes undeniable. At this point in time, I am only
interested in demonstrating the concept. Producing a viable product
for
use in aviation is a long term proposition, requiring real,
disciplined
R&D work and funding.

The problem with treating other glider wings is that each wing is a
unique
problem that has to be studied, then tested iteratively, making
adjustments
to the configuration to arrive at something what works. The process
was
started with Greg Cole's Sparrowhawk, but the first attempt failed
due
largely to poor quality control of the deturbulator itself (a
problem
that
I think will be solved with the next application on my glider) and
the
project was not pursued to the point of success. My own experience,
after
Johnson tested my glider in December 2006, was two failures before
the
present application. And even this application was not up to par
and
had
to be studied with oil flow visualizations to see what the problem
was.

I
finally had to remove some intermediate tapes that were needed for
the
Johnson deturbulators and also smooth the sharp leading edge of the
new
deturbulators with (get this) Scotch tape. Finally, the first
flight
after those modifications essentially reproduced Johnson's
remarkable
third flight in 2006. Bottom line, it takes a lot of work and
persistence
to realize success and there is too little Sinha to go
around...he's
a
bottle neck.

Sorry, but reality is reality!
JEH

I hope this research keeps going since it's about the most
interesting
area
of glider aerodynamics currently. Give these guys some credit. This
is

difficult work.

Even after more than 100 years of practical aerodynamics, there are
still

mysteries in extreme near field boundary layer behavior to be
discovered
but
there are few working in the field since the big money is interested
in
much
higher Reynolds numbers.

Wind tunnel data would be interesting but one suspects the
deturbulator
is

extremely sensitive to micro turbulence embedded in the flow. There
aren't
too may extremely low turbulence wind tunnels in the Reynolds number
range

of interest. Even if this were done, there would be the objection
that
the
data were just "laboratory results" that still had to be 'proved'
in
the
real world. In flight testing has it's place and it's cheaper.

What would be interesting to me would be some measurements from a
static

pressure array (drag rake) behind the TE to see what changes are
caused
by

the deturbulator.



Sumon has taken data with a chord high drag probe, that I built for
him,
in his 9" x 12" wind tunnel. The problem is that the data doesn't
scale very well from such a small tunnel. The deturbulater effects
are
greatly exagerated. Nevertheless, it works for screening ideas before
trying them full scale in our "big tunnel."

JEH

"Chord high drag probe"? You mean like a meter high? Thatsa big
probe!
You may have meant wing thickness high probe. Anyway, put that thing on
the
Cirrus and get before and after in-flight data. That would be more
convincing than comparison glides, at least to me.

Mount a video camera focused on the ASI, Altimeter and a clock. Put a
tiny
pager vibrator motor on the instruments to keep them from sticking.
It's
old fashoned but it works.

Is there a big, low activity runway near you where you could do auto
tows
at
the crack of dawn?
Auto tows are cheap and even if you only get one data point per tow,
they're
worthwhile.

The California dry lakes are (naturally) in desert basins where cold air

collects at night. There's often an isothermal layer up to more than
1000'
AGL by dawn so the air below the inversion is DEAD STILL until about an
hour
or so after sun up - great places to get reliable speed vs sink flight
test
numbers. If you plotted sink rate vs altitude at a constant airspeed, it

would be a straight line until about 50' AGL where ground effects would

start to show up.

I remember doing some tests where we would tow back and forth across the
El
Mirage dry lake. The tow car would be the "chase plane" with a movie
camera
and follow the glider until it landed at the far side of the dry lake.
Then, we'd spin it around and tow it back the other direction. We
could
get
in a dozen flights before the first turbulence was noticed. This would
fill
in the low end of the polar curve in just one morning.

Bill D



bill,

The chord high probe is 5" long and was used with 5" chord wing sections
in the Sinha wind tunnel. There is a page on Sinha's wind tunnel on his
web site.

Aircraft performance is the bottom line. Parallel flying is a cheaper and
quicker way to get relults because both gliders are seeing the same air
movement. You can see this clearly in the Diana data. For a truly
accurate test you need pristine air, but it's the wrong season for that
and a 10,000' tow cost me $119, not the mention the cost of gasoline for
5 hours on the road. So, instead, I opted for 20 minutes of real world
formation flying.

Besides that, the optimal capabilities of a glider mean less than how it
will actually perform in normal turbulence. So I want to know how much of
that narrow performance speed peak I can realize under real soaring
conditions. At this point, it looks like I lose about half of the peak
capabilities of the deturbulator as I analyze the log data from Johnson's
testing. Johnson's measurement over 4 minutes (that's how long it took
to lose 400 feet) averaged out to 64:1 (Dick threw that flight out of his
analysis that gave 18% improvement), so from there I'm losing about one
third. This will become clearer as the data keep coming in.

JEH

At 22:21 10 June 2008, Bill Daniels wrote:

"Jim Hendrix" wrote in message
...
At 14:28 10 June 2008, Bill Daniels wrote:

"Jim Hendrix" wrote in message
...
At 04:04 10 June 2008, Ramy wrote:
On Jun 9, 5:13=A0pm, Jim Hendrix wrote:
...
Looks like the results speak for themselves and it sounds
promissing.
But why does it take so long to turn it into production? According
to
the web site the experiments started at 2003 and so far it was only
tested on a standard cirrus. How longer will it take until I can
have
it on my 27?

Ramy

Ramy,

To be brutally frank, it's taking a long time to develop this
technology
because neither Sumon nor I are very disciplined in our methods and
a
great deal of hard work remains to fully understand both the
flow-surface
interaction of the deturbulator device and the overall wing
aerodynamics
we are achieving with it.

Sumon knows what he wants to achieve, but we are dealing with
subtleties
that extend well beyond his original concept, which were close
enough
to
work but not really on target. I've watched his concepts morph
over
time
regarding both the flow-surface interaction and the wing
aerodynamics
model. We now have a third person loosely associated with the
project
to
model the flow-surface interaction using his LINFLOW software
package,
Jari Hyvärinen of ANKER-ZEMER Engineering AB in Norway.

The slowness comes down to manpower issues. Sumon is almost
completely
committed to developing a deturbulator product for semi tractor
trailer
rigs. As he makes improvements in the trucking device, I
occasionally
divert his attention long enough to upgrade the deturbulators on my
glider. Thus, for example, we now seem to have something that
sometimes
works even in the summer months, if the humidity is not too great.
So
the
main thrust of his attention is directed toward a, technically
easier
and
more lucrative, market. For my part, I have higher priorities, so
the
deturbulator sort of fills in the cracks. Also, I don't have the
aerodynamics background for the fundamental work that needs to be
done;
that will wait until the aerodynamics community sees the light and
begins
doing the work, or large corporations pony up the funds for R&D
projects.
Like me, Jari Hyvärinen needs to make a living with his normal
engineering
consulting work, so for him too this is not a main priority.

Add to that the enormous amount of research and engineering that
remains
to be done to fully understand the modes of flow-surface interaction
that
can occur, those can be exploited for specific aims and those that
must
be
avoided (both are well demonstrated in Johnson's 2006 test flights-
http://sinhatech.com/SinhaFCSD-Progr...on-Details.asp) and you
can
see that we have a bottle neck that is restricting progress. The
sooner
the aerodynamics community takes this seriously, the sooner we will
get
there. For my part, I intend to keep collecting data until the
sheer
weight of it becomes undeniable. At this point in time, I am only
interested in demonstrating the concept. Producing a viable product
for
use in aviation is a long term proposition, requiring real,
disciplined
R&D work and funding.

The problem with treating other glider wings is that each wing is a
unique
problem that has to be studied, then tested iteratively, making
adjustments
to the configuration to arrive at something what works. The process
was
started with Greg Cole's Sparrowhawk, but the first attempt failed
due
largely to poor quality control of the deturbulator itself (a
problem
that
I think will be solved with the next application on my glider) and
the
project was not pursued to the point of success. My own experience,
after
Johnson tested my glider in December 2006, was two failures before
the
present application. And even this application was not up to par
and
had
to be studied with oil flow visualizations to see what the problem
was.

I
finally had to remove some intermediate tapes that were needed for
the
Johnson deturbulators and also smooth the sharp leading edge of the
new
deturbulators with (get this) Scotch tape. Finally, the first
flight
after those modifications essentially reproduced Johnson's
remarkable
third flight in 2006. Bottom line, it takes a lot of work and
persistence
to realize success and there is too little Sinha to go
around...he's
a
bottle neck.

Sorry, but reality is reality!
JEH

I hope this research keeps going since it's about the most
interesting
area
of glider aerodynamics currently. Give these guys some credit. This
is

difficult work.

Even after more than 100 years of practical aerodynamics, there are
still

mysteries in extreme near field boundary layer behavior to be
discovered
but
there are few working in the field since the big money is interested
in
much
higher Reynolds numbers.

Wind tunnel data would be interesting but one suspects the
deturbulator
is

extremely sensitive to micro turbulence embedded in the flow. There
aren't
too may extremely low turbulence wind tunnels in the Reynolds number
range

of interest. Even if this were done, there would be the objection
that
the
data were just "laboratory results" that still had to be 'proved'
in
the
real world. In flight testing has it's place and it's cheaper.

What would be interesting to me would be some measurements from a
static

pressure array (drag rake) behind the TE to see what changes are
caused
by

the deturbulator.



Sumon has taken data with a chord high drag probe, that I built for
him,
in his 9" x 12" wind tunnel. The problem is that the data doesn't
scale very well from such a small tunnel. The deturbulater effects
are
greatly exagerated. Nevertheless, it works for screening ideas before
trying them full scale in our "big tunnel."

JEH

"Chord high drag probe"? You mean like a meter high? Thatsa big
probe!
You may have meant wing thickness high probe. Anyway, put that thing on
the
Cirrus and get before and after in-flight data. That would be more
convincing than comparison glides, at least to me.

Mount a video camera focused on the ASI, Altimeter and a clock. Put a
tiny
pager vibrator motor on the instruments to keep them from sticking.
It's
old fashoned but it works.

Is there a big, low activity runway near you where you could do auto
tows
at
the crack of dawn?
Auto tows are cheap and even if you only get one data point per tow,
they're
worthwhile.

The California dry lakes are (naturally) in desert basins where cold air

collects at night. There's often an isothermal layer up to more than
1000'
AGL by dawn so the air below the inversion is DEAD STILL until about an
hour
or so after sun up - great places to get reliable speed vs sink flight
test
numbers. If you plotted sink rate vs altitude at a constant airspeed, it

would be a straight line until about 50' AGL where ground effects would

start to show up.

I remember doing some tests where we would tow back and forth across the
El
Mirage dry lake. The tow car would be the "chase plane" with a movie
camera
and follow the glider until it landed at the far side of the dry lake.
Then, we'd spin it around and tow it back the other direction. We
could
get
in a dozen flights before the first turbulence was noticed. This would
fill
in the low end of the polar curve in just one morning.

Bill D



bill,

The chord high probe is 5" long and was used with 5" chord wing sections
in the Sinha wind tunnel. There is a page on Sinha's wind tunnel on his
web site.

Aircraft performance is the bottom line. Parallel flying is a cheaper and
quicker way to get relults because both gliders are seeing the same air
movement. You can see this clearly in the Diana data. For a truly
accurate test you need pristine air, but it's the wrong season for that
and a 10,000' tow cost me $119, not the mention the cost of gasoline for
5 hours on the road. So, instead, I opted for 20 minutes of real world
formation flying.

Besides that, the optimal capabilities of a glider mean less than how it
will actually perform in normal turbulence. So I want to know how much of
that narrow performance speed peak I can realize under real soaring
conditions. At this point, it looks like I lose about half of the peak
capabilities of the deturbulator as I analyze the log data from Johnson's
testing. Johnson's measurement over 4 minutes (that's how long it took
to lose 400 feet) averaged out to 64:1 (Dick threw that flight out of his
analysis that gave 18% improvement), so from there I'm losing about one
third. This will become clearer as the data keep coming in.

JEH

On Jun 10, 7:28 pm, Jim Hendrix wrote:
At 22:21 10 June 2008, Bill Daniels wrote:





"Jim Hendrix" wrote in message
...
At 14:28 10 June 2008, Bill Daniels wrote:

"Jim Hendrix" wrote in message
...
At 04:04 10 June 2008, Ramy wrote:
On Jun 9, 5:13=A0pm, Jim Hendrix wrote:
...
Looks like the results speak for themselves and it sounds
promissing.
But why does it take so long to turn it into production? According
to
the web site the experiments started at 2003 and so far it was only
tested on a standard cirrus. How longer will it take until I can
have
it on my 27?

Ramy

Ramy,

To be brutally frank, it's taking a long time to develop this
technology
because neither Sumon nor I are very disciplined in our methods and
a
great deal of hard work remains to fully understand both the
flow-surface
interaction of the deturbulator device and the overall wing
aerodynamics
we are achieving with it.

Sumon knows what he wants to achieve, but we are dealing with
subtleties
that extend well beyond his original concept, which were close
enough
to
work but not really on target. I've watched his concepts morph
over
time
regarding both the flow-surface interaction and the wing
aerodynamics
model. We now have a third person loosely associated with the
project
to
model the flow-surface interaction using his LINFLOW software
package,
Jari Hyvärinen of ANKER-ZEMER Engineering AB in Norway.

The slowness comes down to manpower issues. Sumon is almost
completely
committed to developing a deturbulator product for semi tractor
trailer
rigs. As he makes improvements in the trucking device, I
occasionally
divert his attention long enough to upgrade the deturbulators on my
glider. Thus, for example, we now seem to have something that
sometimes
works even in the summer months, if the humidity is not too great.
So
the
main thrust of his attention is directed toward a, technically
easier
and
more lucrative, market. For my part, I have higher priorities, so
the
deturbulator sort of fills in the cracks. Also, I don't have the
aerodynamics background for the fundamental work that needs to be
done;
that will wait until the aerodynamics community sees the light and
begins
doing the work, or large corporations pony up the funds for R&D
projects.
Like me, Jari Hyvärinen needs to make a living with his normal
engineering
consulting work, so for him too this is not a main priority.

Add to that the enormous amount of research and engineering that
remains
to be done to fully understand the modes of flow-surface interaction
that
can occur, those can be exploited for specific aims and those that
must
be
avoided (both are well demonstrated in Johnson's 2006 test flights-
http://sinhatech.com/SinhaFCSD-Progr...on-Details.asp) and you
can
see that we have a bottle neck that is restricting progress. The
sooner
the aerodynamics community takes this seriously, the sooner we will
get
there. For my part, I intend to keep collecting data until the
sheer
weight of it becomes undeniable. At this point in time, I am only
interested in demonstrating the concept. Producing a viable product
for
use in aviation is a long term proposition, requiring real,
disciplined
R&D work and funding.

The problem with treating other glider wings is that each wing is a
unique
problem that has to be studied, then tested iteratively, making
adjustments
to the configuration to arrive at something what works. The process
was
started with Greg Cole's Sparrowhawk, but the first attempt failed
due
largely to poor quality control of the deturbulator itself (a
problem
that
I think will be solved with the next application on my glider) and
the
project was not pursued to the point of success. My own experience,
after
Johnson tested my glider in December 2006, was two failures before
the
present application. And even this application was not up to par
and
had
to be studied with oil flow visualizations to see what the problem
was.

I
finally had to remove some intermediate tapes that were needed for
the
Johnson deturbulators and also smooth the sharp leading edge of the
new
deturbulators with (get this) Scotch tape. Finally, the first
flight
after those modifications essentially reproduced Johnson's
remarkable
third flight in 2006. Bottom line, it takes a lot of work and
persistence
to realize success and there is too little Sinha to go
around...he's
a
bottle neck.

Sorry, but reality is reality!
JEH

I hope this research keeps going since it's about the most
interesting
area
of glider aerodynamics currently. Give these guys some credit. This
is

difficult work.

Even after more than 100 years of practical aerodynamics, there are
still

mysteries in extreme near field boundary layer behavior to be
discovered
but
there are few working in the field since the big money is interested
in
much
higher Reynolds numbers.

Wind tunnel data would be interesting but one suspects the
deturbulator
is

extremely sensitive to micro turbulence embedded in the flow. There
aren't
too may extremely low turbulence wind tunnels in the Reynolds number
range

of interest. Even if this were done, there would be the objection
that
the
data were just "laboratory results" that still had to be 'proved'
in
the
real world. In flight testing has it's place and it's cheaper.

What would be interesting to me would be some measurements from a
static

pressure array (drag rake) behind the TE to see what changes are
caused
by

the deturbulator.

Sumon has taken data with a chord high drag probe, that I built for
him,
in his 9" x 12" wind tunnel. The problem is that the data doesn't
scale very well from such a small tunnel. The deturbulater effects
are
greatly exagerated. Nevertheless, it works for screening ideas before
trying them full scale in our "big tunnel."

JEH

"Chord high drag probe"? You mean like a meter high? Thatsa big
probe!
You may have meant wing thickness high probe. Anyway, put that thing on
the
Cirrus and get before and after in-flight data. That would be more
convincing than comparison glides, at least to me.

Mount a video camera focused on the ASI, Altimeter and a clock. Put a
tiny
pager vibrator motor on the instruments to keep them from sticking.
It's
old fashoned but it works.

Is there a big, low activity runway near you where you could do auto
tows
at
the crack of dawn?
Auto tows are cheap and even if you only get one data point per tow,
they're
worthwhile.

The California dry lakes are (naturally) in desert basins where cold air
collects at night. There's often an isothermal layer up to more than
1000'
AGL by dawn so the air below the inversion is DEAD STILL until about an
hour
or so after sun up - great places to get reliable speed vs sink flight
test
numbers. If you plotted sink rate vs altitude at a constant airspeed, it
would be a straight line until about 50' AGL where ground effects would
start to show up.

I remember doing some tests where we would tow back and forth across the
El
Mirage dry lake. The tow car would be the "chase plane" with a movie
camera
and follow the glider until it landed at the far side of the dry lake.
Then, we'd spin it around and tow it back the other direction. We
could
get
in a dozen flights before the first turbulence was noticed. This would
fill
in the low end of the polar curve in just one morning.

Bill D

bill,

The chord high probe is 5" long and was used with 5" chord wing sections
in the Sinha wind tunnel. There is a page on Sinha's wind tunnel on his
web site.

Aircraft performance is the bottom line. Parallel flying is a cheaper and
quicker way to get relults because both gliders are seeing the same air
movement. You can see this clearly in the Diana data. For a truly
accurate test you need pristine air, but it's the wrong season for that
and a 10,000' tow cost me $119, not the mention the cost of gasoline for
5 hours on the road. So, instead, I opted for 20 minutes of real world
formation flying.

Besides that, the optimal capabilities of a glider mean less than how it
will actually perform in normal turbulence. So I want to know how much of
that narrow performance speed peak I can realize under real soaring
conditions. At this point, it looks like I lose about half of the peak
capabilities of the deturbulator as I analyze the log data from Johnson's
testing. Johnson's measurement over 4 minutes (that's how long it took
to lose 400 feet) averaged out to 64:1 (Dick threw that flight out of his
analysis that gave 18% improvement), so from there I'm losing about one
third. This will become clearer as the data keep coming in.

JEH

This is fascinating stuff! Jim, would you clarify a detail on how you
did your "parallel" test runs. Were you wing to wing or were you in
echelon with one glider somewhat ahead? Echelon flight has been known
to improve the performance of the following aircraft.

Rudy Allemann

At 07:21 12 June 2008, Rudy Allemann 7Y wrote:
On Jun 10, 7:28 pm, Jim Hendrix wrote:
At 22:21 10 June 2008, Bill Daniels wrote:





"Jim Hendrix" wrote in message
...
At 14:28 10 June 2008, Bill Daniels wrote:

"Jim Hendrix" wrote in message
...
At 04:04 10 June 2008, Ramy wrote:
On Jun 9, 5:13=3DA0pm, Jim Hendrix wrote:
...
Looks like the results speak for themselves and it sounds
promissing.
But why does it take so long to turn it into production?
According
to
the web site the experiments started at 2003 and so far it was
only
tested on a standard cirrus. How longer will it take until I can
have
it on my 27?

Ramy

Ramy,

To be brutally frank, it's taking a long time to develop this
technology
because neither Sumon nor I are very disciplined in our methods
and
a
great deal of hard work remains to fully understand both the
flow-surface
interaction of the deturbulator device and the overall wing
aerodynamics
we are achieving with it.

Sumon knows what he wants to achieve, but we are dealing with
subtleties
that extend well beyond his original concept, which were close
enough
to
work but not really on target. I've watched his concepts morph
over
time
regarding both the flow-surface interaction and the wing
aerodynamics
model. We now have a third person loosely associated with the
project
to
model the flow-surface interaction using his LINFLOW software
package,
Jari Hyv=E4rinen of ANKER-ZEMER Engineering AB in Norway.

The slowness comes down to manpower issues. Sumon is almost
completely
committed to developing a deturbulator product for semi tractor
trailer
rigs. As he makes improvements in the trucking device, I
occasionally
divert his attention long enough to upgrade the deturbulators on
my
glider. Thus, for example, we now seem to have something that
sometimes
works even in the summer months, if the humidity is not too
great.
So
the
main thrust of his attention is directed toward a, technically
easier
and
more lucrative, market. For my part, I have higher priorities,
so
the
deturbulator sort of fills in the cracks. Also, I don't have
the
aerodynamics background for the fundamental work that needs to be
done;
that will wait until the aerodynamics community sees the light
and
begins
doing the work, or large corporations pony up the funds for R&D
projects.
Like me, Jari Hyv=E4rinen needs to make a living with his normal
engineering
consulting work, so for him too this is not a main priority.

Add to that the enormous amount of research and engineering that
remains
to be done to fully understand the modes of flow-surface
interaction
that
can occur, those can be exploited for specific aims and those
that
must
be
avoided (both are well demonstrated in Johnson's 2006 test
flights-
http://sinhatech.com/SinhaFCSD-Progr...on-Details.asp) and
you
can
see that we have a bottle neck that is restricting progress. The
sooner
the aerodynamics community takes this seriously, the sooner we
will
get
there. For my part, I intend to keep collecting data until the
sheer
weight of it becomes undeniable. At this point in time, I am
only
interested in demonstrating the concept. Producing a viable
product
for
use in aviation is a long term proposition, requiring real,
disciplined
R&D work and funding.

The problem with treating other glider wings is that each wing is
a
unique
problem that has to be studied, then tested iteratively, making
adjustments
to the configuration to arrive at something what works. The
process
was
started with Greg Cole's Sparrowhawk, but the first attempt
failed
due
largely to poor quality control of the deturbulator itself (a
problem
that
I think will be solved with the next application on my glider)
and
the
project was not pursued to the point of success. My own
experience,
after
Johnson tested my glider in December 2006, was two failures
before
the
present application. And even this application was not up to par
and
had
to be studied with oil flow visualizations to see what the
problem
was.

I
finally had to remove some intermediate tapes that were needed
for
the
Johnson deturbulators and also smooth the sharp leading edge of
the
new
deturbulators with (get this) Scotch tape. Finally, the first
flight
after those modifications essentially reproduced Johnson's
remarkable
third flight in 2006. Bottom line, it takes a lot of work and
persistence
to realize success and there is too little Sinha to go
around...he's
a
bottle neck.

Sorry, but reality is reality!
JEH

I hope this research keeps going since it's about the most
interesting
area
of glider aerodynamics currently. Give these guys some credit.
This
is

difficult work.

Even after more than 100 years of practical aerodynamics, there are
still

mysteries in extreme near field boundary layer behavior to be
discovered
but
there are few working in the field since the big money is
interested
in
much
higher Reynolds numbers.

Wind tunnel data would be interesting but one suspects the
deturbulator
is

extremely sensitive to micro turbulence embedded in the flow.
There
aren't
too may extremely low turbulence wind tunnels in the Reynolds
number
range

of interest. Even if this were done, there would be the objection
that
the
data were just "laboratory results" that still had to be
'proved'
in
the
real world. In flight testing has it's place and it's cheaper.

What would be interesting to me would be some measurements from a
static

pressure array (drag rake) behind the TE to see what changes are
caused
by

the deturbulator.

Sumon has taken data with a chord high drag probe, that I built for
him,
in his 9" x 12" wind tunnel. The problem is that the data
doesn't
scale very well from such a small tunnel. The deturbulater effects
are
greatly exagerated. Nevertheless, it works for screening ideas
before
trying them full scale in our "big tunnel."

JEH

"Chord high drag probe"? You mean like a meter high? Thatsa big
probe!
You may have meant wing thickness high probe. Anyway, put that thing
on
the
Cirrus and get before and after in-flight data. That would be more
convincing than comparison glides, at least to me.

Mount a video camera focused on the ASI, Altimeter and a clock. Put
a
tiny
pager vibrator motor on the instruments to keep them from sticking.
It's
old fashoned but it works.

Is there a big, low activity runway near you where you could do auto
tows
at
the crack of dawn?
Auto tows are cheap and even if you only get one data point per tow,
they're
worthwhile.

The California dry lakes are (naturally) in desert basins where cold
air
collects at night. There's often an isothermal layer up to more
than
1000'
AGL by dawn so the air below the inversion is DEAD STILL until about
an
hour
or so after sun up - great places to get reliable speed vs sink
flight
test
numbers. If you plotted sink rate vs altitude at a constant
airspeed,
it=

would be a straight line until about 50' AGL where ground effects
would
start to show up.

I remember doing some tests where we would tow back and forth across
the
El
Mirage dry lake. The tow car would be the "chase plane" with a
movie
camera
and follow the glider until it landed at the far side of the dry
lake.
Then, we'd spin it around and tow it back the other direction. We
could
get
in a dozen flights before the first turbulence was noticed. This
would
fill
in the low end of the polar curve in just one morning.

Bill D

bill,

The chord high probe is 5" long and was used with 5" chord wing
sections
in the Sinha wind tunnel. There is a page on Sinha's wind tunnel on
his
web site.

Aircraft performance is the bottom line. Parallel flying is a cheaper
and=

quicker way to get relults because both gliders are seeing the same
air
movement. You can see this clearly in the Diana data. For a truly
accurate test you need pristine air, but it's the wrong season for
that
and a 10,000' tow cost me $119, not the mention the cost of gasoline
for
5 hours on the road. So, instead, I opted for 20 minutes of real
world
formation flying.

Besides that, the optimal capabilities of a glider mean less than how
it
will actually perform in normal turbulence. So I want to know how
much
of=

that narrow performance speed peak I can realize under real soaring
conditions. At this point, it looks like I lose about half of the
peak
capabilities of the deturbulator as I analyze the log data from
Johnson's
testing. Johnson's measurement over 4 minutes (that's how long it
took
to lose 400 feet) averaged out to 64:1 (Dick threw that flight out of
his
analysis that gave 18% improvement), so from there I'm losing about
one
third. This will become clearer as the data keep coming in.

JEH

This is fascinating stuff! Jim, would you clarify a detail on how you
did your "parallel" test runs. Were you wing to wing or were you in
echelon with one glider somewhat ahead? Echelon flight has been known
to improve the performance of the following aircraft.

Rudy Allemann

Rudy,

It was an echelon formation with the Diana off my left wing and slightly
behind. There was enough space that there that I doubt that the Diana
received a boost from my wing tip vortex. :-)

Download the two IGC files and replay them simultaneously in SeeYou. You
can see exactly how it went. There are cropped IGC files also so yo
don't have to view all of the preliminaries leading to the parallel
flight legs.

The web page is at http://sinhatech.com/SinhaFCSD-Progress-06072008.asp .

JEH