deturbulated std cirrus flies against Diana 1

[Jim Hendrix]

For the latest parallel flight of my deturbulated Standard Cirrus vs. a
modern glider, go to
http://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

www.oxaero.com

[[email protected]]

On Jun 9, 2:58*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
>

Jim,

How narrow is the airspeed "sweet spot" for achieving these
performance gains? From the looks of the presentations on the
website, it seems like it might be rather small. Are there any
handling characteristics that are affected by the modifications such
as stall, slow speed, thermalling, etc.?


Dave

[Jim Hendrix]

At 20:39 09 June 2008, wrote:
>On Jun 9, 2:58=A0pm, 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#a=
>rticle.
>>
>> 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
>>
>
>Jim,
>
>How narrow is the airspeed "sweet spot" for achieving these
>performance gains? From the looks of the presentations on the
>website, it seems like it might be rather small. Are there any
>handling characteristics that are affected by the modifications such
>as stall, slow speed, thermalling, etc.?
>
>
>Dave
>
Dave,

The narrowness of the extreme performance peak near 50 KIA is seen in the
third graph on page http://sinhatech.com/SinhaFCSD-Progress-12012007.asp .
The two neighboring speed points are 2.5 kts on either side, or 5 kts
apart. That I was not accounting for my additional weight and was flying
too slow at 50 KIA is seen in the 47.5 point being higher than the 52.5
KIA point. I believe that is the reason that my extreme performance
flight on 12/1/07 only reached 70:1 whereas Johnson's a year earlier
reached over 100:1. This is confirmed by my second 50 run on 12/1/07 in
which excessive pitch momentum arriving at the magic speed made the AOA
and deturbulator performance "hunt" each other such that the performance
swung between Johnson's performance at the top and baseline at the bottom
(Click Extreme Performance powerpoint link and scroll to the bottom for
that graph.).

It is interesting that if, as it appears, my ship was matching a 45:1
glider, that is about the performance level between the neighboring speed
points I used to define the performance peak width. So, the polar from
12/1/08 closely matches the Diana performance I saw last Saturday.

Stall speed is not affected significantly. Neither is handline, though
there are a number of interesting effects from flying with wings that
change moment to moment. Lately I've been experimenting with instantly
improving performance by pulling up to nearly a stall and slowly settling
down to 51 KIA. It seems that often this gives me a quick performance
boost.

JEH

[[email protected]]

On Jun 9, 4:13*pm, Jim Hendrix > wrote:
> At 20:39 09 June 2008, wrote:
>
>
>
> >On Jun 9, 2:58=A0pm, 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#a=
> >rticle.
>
> >> 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
> >>
>
> >Jim,
>
> >How narrow is the airspeed "sweet spot" for achieving these
> >performance gains? *From the looks of the presentations on the
> >website, it seems like it might be rather small. Are there any
> >handling characteristics that are affected by the modifications such
> >as stall, slow speed, thermalling, etc.?
>
> >Dave
>
> Dave,
>
> The narrowness of the extreme performance peak near 50 KIA is seen in the
> third graph on pagehttp://sinhatech.com/SinhaFCSD-Progress-12012007.asp.
> *The two neighboring speed points are 2.5 kts on either side, or 5 kts
> apart. *That I was not accounting for my additional weight and was flying
> too slow at 50 KIA is seen in the 47.5 point being higher than the 52.5
> KIA point. *I believe that is the reason that my extreme performance
> flight on 12/1/07 only reached 70:1 whereas Johnson's a year earlier
> reached over 100:1. *This is confirmed by my second 50 run on 12/1/07 in
> which excessive pitch momentum arriving at the magic speed made the AOA
> and deturbulator performance "hunt" each other such that the performance
> swung between Johnson's performance at the top and baseline at the bottom
> (Click Extreme Performance powerpoint link and scroll to the bottom for
> that graph.).
>
> It is interesting that if, as it appears, my ship was matching a 45:1
> glider, that is about the performance level between the neighboring speed
> points I used to define the performance peak width. *So, the polar from
> 12/1/08 closely matches the Diana performance I saw last Saturday.
>
> Stall speed is not affected significantly. *Neither is handline, though
> there are a number of interesting effects from flying with wings that
> change moment to moment. *Lately I've been experimenting with instantly
> improving performance by pulling up to nearly a stall and slowly settling
> down to 51 KIA. *It seems that often this gives me a quick performance
> boost.
>
> JEH- Hide quoted text -
>
> - Show quoted text -

Jim,

Thanks for the info. Some additional questions for you. What do you
"feel" in the aircraft when this "AOA
and deturbulator performance hunt" is going on? Is there some kind of
noticable oscillation going on? What are some of the other
"interesting effects"?


Dave

[Jim Hendrix]

At 21:30 09 June 2008, wrote:
>On Jun 9, 4:13=A0pm, Jim Hendrix wrote:
>> At 20:39 09 June 2008, wrote:
>>
>>
>>
>> >On Jun 9, 2:58=3DA0pm, Jim Hendrix =A0wrote:
>> >> For the latest parallel flight of my deturbulated Standard Cirrus
vs.
>> a
>> >> modern glider, go
>> >tohttp://sinhatech.com/SinhaFCSD-Progress-06072008.asp#a=3D
>> >rticle.
>>
>> >> 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
>> >>
>>
>> >Jim,
>>
>> >How narrow is the airspeed "sweet spot" for achieving these
>> >performance gains? =A0From the looks of the presentations on the
>> >website, it seems like it might be rather small. Are there any
>> >handling characteristics that are affected by the modifications such
>> >as stall, slow speed, thermalling, etc.?
>>
>> >Dave
>>
>> Dave,
>>
>> The narrowness of the extreme performance peak near 50 KIA is seen in
>the
>> third graph on
pagehttp://sinhatech.com/SinhaFCSD-Progress-12012007.asp.
>> =A0The two neighboring speed points are 2.5 kts on either side, or 5
kts
>> apart. =A0That I was not accounting for my additional weight and was
>flyin=
>g
>> too slow at 50 KIA is seen in the 47.5 point being higher than the
52.5
>> KIA point. =A0I believe that is the reason that my extreme performance
>> flight on 12/1/07 only reached 70:1 whereas Johnson's a year earlier
>> reached over 100:1. =A0This is confirmed by my second 50 run on
12/1/07
>in=
>
>> which excessive pitch momentum arriving at the magic speed made the
AOA
>> and deturbulator performance "hunt" each other such that the
performance
>> swung between Johnson's performance at the top and baseline at the
>bottom
>> (Click Extreme Performance powerpoint link and scroll to the bottom
for
>> that graph.).
>>
>> It is interesting that if, as it appears, my ship was matching a 45:1
>> glider, that is about the performance level between the neighboring
>speed
>> points I used to define the performance peak width. =A0So, the polar
>from
>> 12/1/08 closely matches the Diana performance I saw last Saturday.
>>
>> Stall speed is not affected significantly. =A0Neither is handline,
>though
>> there are a number of interesting effects from flying with wings that
>> change moment to moment. =A0Lately I've been experimenting with
>instantly
>> improving performance by pulling up to nearly a stall and slowly
>settling
>> down to 51 KIA. =A0It seems that often this gives me a quick
performance
>> boost.
>>
>> JEH- Hide quoted text -
>>
>> - Show quoted text -
>
>Jim,
>
>Thanks for the info. Some additional questions for you. What do you
>"feel" in the aircraft when this "AOA
>and deturbulator performance hunt" is going on? Is there some kind of
>noticable oscillation going on? What are some of the other
>"interesting effects"?
>
>
>Dave
>
Dave,

I measured this only once. I felt nothing that I recall, but was a bit
perturbed that the vario was not as steady as for the first 50 kt run in
that flight. Of course, at the time I had no idea what was going on. My
thinking is that when it was hunting, it was sweping back and forth past
the "magic" airspeed that I didn't realize should have been around 51
KIA.

JEH

[Mark Dickson[_2_]]

If both gliders were flying at about 51 kts, doesn't this give the Cirrus
an advantage? 51 kts probably gives best l/d for the Cirrus, but it will
be well below best l/d for the diana.

[Jim Hendrix]

At 22:28 09 June 2008, Mark Dickson wrote:
>If both gliders were flying at about 51 kts, doesn't this give the
Cirrus
>an advantage? 51 kts probably gives best l/d for the Cirrus, but it
will
>be well below best l/d for the diana.
>
Mark,

That is a good question and one that I have not taken the time to look
deeply into.

According to the polar Johnson measured, the Diana 1 has a sink rate dip
at 53 kts calibrated that gives it 45:1. We were trying to fly 51 KIA on
my ship which is about 51.25 calibrated, or 1.75 kts slower than the Diana
likes. At that speed Johnson gives the Diana about 115 fpm sink rate for
an L/D of 44.1. This would still be 10.6 points higher than my ship
measured. However, especially on the cloud-street run, both ships were
flying though turbulence that bounced the airspeed all over the range that
covered my performance peak and the Diana’s too. So, we’re dealing with
ball park numbers here.

JEH

[Ramy]

On Jun 9, 5:13*pm, Jim Hendrix > wrote:
> At 22:28 09 June 2008, Mark Dickson wrote:>If both gliders were flying at about 51 kts, doesn't this give the
> Cirrus
> >an advantage? *51 kts probably gives best l/d for the Cirrus, but it
> will
> >be well below best l/d for the diana.
>
> Mark,
>
> That is a good question and one that I have not taken the time to look
> deeply into.
>
> According to the polar Johnson measured, the Diana 1 has a sink rate dip
> at 53 kts calibrated that gives it 45:1. *We were trying to fly 51 KIA on
> my ship which is about 51.25 calibrated, or 1.75 kts slower than the Diana
> likes. *At that speed Johnson gives the Diana about 115 fpm sink rate for
> an L/D of 44.1. *This would still be 10.6 points higher than my ship
> measured. *However, especially on the cloud-street run, both ships were
> flying though turbulence that bounced the airspeed all over the range that
> covered my performance peak and the Diana’s too. *So, we’re dealing with
> ball park numbers here.
>
> JEH

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

[Matt Herron Jr.]

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

[Jim Hendrix]

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-Progress-Johnson-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

[Jim Hendrix]

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

[Bill Daniels]

"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-Progress-Johnson-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.

[Jim Hendrix]

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-Progress-Johnson-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

[Bill Daniels]

"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-Progress-Johnson-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

[Jim Hendrix]

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-Progress-Johnson-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

[Jim Hendrix]

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-Progress-Johnson-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

[Jim Hendrix]

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-Progress-Johnson-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

[Rudy Allemann 7Y]

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-Progress-Johnson-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

[Jim Hendrix]

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-Progress-Johnson-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