XC Dynamic Soaring along cloud streets

Why aren't we all doing this?

http://youtu.be/Ln9fuR8uwIc?t=36m48s

I'd give it a try if I thought I understood what the nature of the shear is that is being exploited and how to work it. I am inclined to think that whatever the nature of this "longitudinal shear", it isn't terribly commonplace, but if I were wrong about that, I'd really like to know!!

Evan Ludeman / T8

Why aren't we all doing this?

http://youtu.be/Ln9fuR8uwIc?t=36m48s

Evan Ludeman / T8

I've been thinking about dynamic soaring a bit. (It's 5 below outside, and sick of finish height wars...) One thing that would help a lot is instrumentation. Dynamic soaring works, most basically, by pulling more Gs when the aerodynamic force vector (L+D) has a component pointing in the direction of motion. Then, pulling harder speeds the glider up. A sudden gust of lift, for example, rotates the relative wind so that pulling more g pushes the glider forward.

The trouble is, it's very hard for the human butt to detect this condition. Gs help, but you need to know a sort of total energy compensated g -- how much g should there be vs. how much is there. And even g isn't a perfect measure of what we're looking for.

The modern vario has the ingredients to detect this condition -- put gps, three axis gyros, magnetic heading, three axis g, airspeed and TE together, stir the pot and issue pull push commands (or feed them to the stick, but that's an extra project)

At a deeper level the modern vario could directly measure outside air movement. Compare GPS track with 3d relative air movement, and you know what the air is doing. (Plus a year's worth of filtering and adjusting...) This could tell us the air is going up long before it accelerates the glider up, the glider starts moving up, and the vario notices. That's the window for a dynamic soaring move.

In the same way the vario can detect sideways gusts, such as these shears near cloudstreets. Or guide you to backside of the ridge dynamic soaring by helping you to know when you're in the wind shadow.

The modern vario... Like the CN vario... Don't you work for CN? They keep sending my wild ideas to the spam filter these days...Something about "development budgets", "markets of one customer," "hare-brained schemes" and other business-ese

John Cochrane

Carl Herold used to talk about doing this in the Great Basin. Regrettably, I was never able to soar with him while he was flying out of Ely. Fred

Maybe Gary Osoba will chime in...


wrote in message
...
Carl Herold used to talk about doing this in the Great Basin.
Regrettably, I was never able to soar with him while he was flying out of
Ely. Fred

On Monday, January 27, 2014 10:18:45 AM UTC-5, wrote:
Why aren't we all doing this?



http://youtu.be/Ln9fuR8uwIc?t=36m48s



Evan Ludeman / T8



I've been thinking about dynamic soaring a bit. (It's 5 below outside, and sick of finish height wars...) One thing that would help a lot is instrumentation. Dynamic soaring works, most basically, by pulling more Gs when the aerodynamic force vector (L+D) has a component pointing in the direction of motion. Then, pulling harder speeds the glider up. A sudden gust of lift, for example, rotates the relative wind so that pulling more g pushes the glider forward.



The trouble is, it's very hard for the human butt to detect this condition. Gs help, but you need to know a sort of total energy compensated g -- how much g should there be vs. how much is there. And even g isn't a perfect measure of what we're looking for.



The modern vario has the ingredients to detect this condition -- put gps, three axis gyros, magnetic heading, three axis g, airspeed and TE together, stir the pot and issue pull push commands (or feed them to the stick, but that's an extra project)



At a deeper level the modern vario could directly measure outside air movement. Compare GPS track with 3d relative air movement, and you know what the air is doing. (Plus a year's worth of filtering and adjusting...) This could tell us the air is going up long before it accelerates the glider up, the glider starts moving up, and the vario notices. That's the window for a dynamic soaring move.



In the same way the vario can detect sideways gusts, such as these shears near cloudstreets. Or guide you to backside of the ridge dynamic soaring by helping you to know when you're in the wind shadow.



The modern vario... Like the CN vario... Don't you work for CN? They keep sending my wild ideas to the spam filter these days...Something about "development budgets", "markets of one customer," "hare-brained schemes" and other business-ese



John Cochrane


Related, I suspect: the Katzmayr effect. This article describes what is essentially a dynamic soaring theory for the (at the time) puzzling phenomenon of reduced drag in an environment with medium frequency vertical oscillation.

https://ia600507.us.archive.org/10/i...9930081006.pdf

It might be that Gary's flying "on the edge of a cloud street" is the same sort of dynamic soaring, at larger scale, with much slower period and with pilot added variation in load factor.

Let's have the vario conversation off line.

Best,
Evan Ludeman / T8

Let's have the vario conversation off line.


Could be an interesting discussion, hope you guys keep it on R.A.S

Luke

On Monday, January 27, 2014 10:18:45 AM UTC-5, wrote:
Why aren't we all doing this?



http://youtu.be/Ln9fuR8uwIc?t=36m48s



Evan Ludeman / T8



I've been thinking about dynamic soaring a bit. (It's 5 below outside, and sick of finish height wars...) One thing that would help a lot is instrumentation. Dynamic soaring works, most basically, by pulling more Gs when the aerodynamic force vector (L+D) has a component pointing in the direction of motion. Then, pulling harder speeds the glider up. A sudden gust of lift, for example, rotates the relative wind so that pulling more g pushes the glider forward.



The trouble is, it's very hard for the human butt to detect this condition. Gs help, but you need to know a sort of total energy compensated g -- how much g should there be vs. how much is there. And even g isn't a perfect measure of what we're looking for.



The modern vario has the ingredients to detect this condition -- put gps, three axis gyros, magnetic heading, three axis g, airspeed and TE together, stir the pot and issue pull push commands (or feed them to the stick, but that's an extra project)



At a deeper level the modern vario could directly measure outside air movement. Compare GPS track with 3d relative air movement, and you know what the air is doing. (Plus a year's worth of filtering and adjusting...) This could tell us the air is going up long before it accelerates the glider up, the glider starts moving up, and the vario notices. That's the window for a dynamic soaring move.



In the same way the vario can detect sideways gusts, such as these shears near cloudstreets. Or guide you to backside of the ridge dynamic soaring by helping you to know when you're in the wind shadow.



The modern vario... Like the CN vario... Don't you work for CN? They keep sending my wild ideas to the spam filter these days...Something about "development budgets", "markets of one customer," "hare-brained schemes" and other business-ese



John Cochrane

John, do we really need much more than a total energy vario? if you dive into a wind shadow, it will register on a te system, I agree that there would be a lot of benefit to having an instantaneous wind measurement system, but it seems that if you can detect a system where you have a good usable (there lies the rub) shear system, it seems a good TE system would be all you would really need.

it is a fascinating area left for us to exploit. I was talking to Paul Maccready about recearch that Taras Kiceniuk was working on (many years ago). He had said that in a system of dead air, interspersed with regular pockets of 100fpm sink, could be exploited to produce level flight. very interesting...

Rick Roelke

On Thursday, January 30, 2014 4:31:12 PM UTC-5, RR wrote:
On Monday, January 27, 2014 10:18:45 AM UTC-5, wrote:

Why aren't we all doing this?







http://youtu.be/Ln9fuR8uwIc?t=36m48s







Evan Ludeman / T8







I've been thinking about dynamic soaring a bit. (It's 5 below outside, and sick of finish height wars...) One thing that would help a lot is instrumentation. Dynamic soaring works, most basically, by pulling more Gs when the aerodynamic force vector (L+D) has a component pointing in the direction of motion. Then, pulling harder speeds the glider up. A sudden gust of lift, for example, rotates the relative wind so that pulling more g pushes the glider forward.







The trouble is, it's very hard for the human butt to detect this condition. Gs help, but you need to know a sort of total energy compensated g -- how much g should there be vs. how much is there. And even g isn't a perfect measure of what we're looking for.







The modern vario has the ingredients to detect this condition -- put gps, three axis gyros, magnetic heading, three axis g, airspeed and TE together, stir the pot and issue pull push commands (or feed them to the stick, but that's an extra project)







At a deeper level the modern vario could directly measure outside air movement. Compare GPS track with 3d relative air movement, and you know what the air is doing. (Plus a year's worth of filtering and adjusting...) This could tell us the air is going up long before it accelerates the glider up, the glider starts moving up, and the vario notices. That's the window for a dynamic soaring move.







In the same way the vario can detect sideways gusts, such as these shears near cloudstreets. Or guide you to backside of the ridge dynamic soaring by helping you to know when you're in the wind shadow.







The modern vario... Like the CN vario... Don't you work for CN? They keep sending my wild ideas to the spam filter these days...Something about "development budgets", "markets of one customer," "hare-brained schemes" and other business-ese







John Cochrane



John, do we really need much more than a total energy vario? if you dive into a wind shadow, it will register on a te system, I agree that there would be a lot of benefit to having an instantaneous wind measurement system, but it seems that if you can detect a system where you have a good usable (there lies the rub) shear system, it seems a good TE system would be all you would really need.



it is a fascinating area left for us to exploit. I was talking to Paul Maccready about recearch that Taras Kiceniuk was working on (many years ago).. He had said that in a system of dead air, interspersed with regular pockets of 100fpm sink, could be exploited to produce level flight. very interesting...



Rick Roelke

Your TE vario will indicate a gain when you are gaining. Some brave soul needs to fly into strong sink at high speed, push on the stick, and see if he can make the vario go up. I doubt a positive G optimized sailplane and human pilot can do this.


Evan Ludeman

On Thursday, January 30, 2014 5:15:24 PM UTC-5, Evan Ludeman wrote:
On Thursday, January 30, 2014 4:31:12 PM UTC-5, RR wrote:

On Monday, January 27, 2014 10:18:45 AM UTC-5, wrote:



Why aren't we all doing this?















http://youtu.be/Ln9fuR8uwIc?t=36m48s















Evan Ludeman / T8















I've been thinking about dynamic soaring a bit. (It's 5 below outside, and sick of finish height wars...) One thing that would help a lot is instrumentation. Dynamic soaring works, most basically, by pulling more Gs when the aerodynamic force vector (L+D) has a component pointing in the direction of motion. Then, pulling harder speeds the glider up. A sudden gust of lift, for example, rotates the relative wind so that pulling more g pushes the glider forward.















The trouble is, it's very hard for the human butt to detect this condition. Gs help, but you need to know a sort of total energy compensated g -- how much g should there be vs. how much is there. And even g isn't a perfect measure of what we're looking for.















The modern vario has the ingredients to detect this condition -- put gps, three axis gyros, magnetic heading, three axis g, airspeed and TE together, stir the pot and issue pull push commands (or feed them to the stick, but that's an extra project)















At a deeper level the modern vario could directly measure outside air movement. Compare GPS track with 3d relative air movement, and you know what the air is doing. (Plus a year's worth of filtering and adjusting...) This could tell us the air is going up long before it accelerates the glider up, the glider starts moving up, and the vario notices. That's the window for a dynamic soaring move.















In the same way the vario can detect sideways gusts, such as these shears near cloudstreets. Or guide you to backside of the ridge dynamic soaring by helping you to know when you're in the wind shadow.















The modern vario... Like the CN vario... Don't you work for CN? They keep sending my wild ideas to the spam filter these days...Something about "development budgets", "markets of one customer," "hare-brained schemes" and other business-ese















John Cochrane







John, do we really need much more than a total energy vario? if you dive into a wind shadow, it will register on a te system, I agree that there would be a lot of benefit to having an instantaneous wind measurement system, but it seems that if you can detect a system where you have a good usable (there lies the rub) shear system, it seems a good TE system would be all you would really need.







it is a fascinating area left for us to exploit. I was talking to Paul Maccready about recearch that Taras Kiceniuk was working on (many years ago). He had said that in a system of dead air, interspersed with regular pockets of 100fpm sink, could be exploited to produce level flight. very interesting...







Rick Roelke



Your TE vario will indicate a gain when you are gaining. Some brave soul needs to fly into strong sink at high speed, push on the stick, and see if he can make the vario go up. I doubt a positive G optimized sailplane and human pilot can do this.





Evan Ludeman

See http://www.icarusengineering.com/Dyn...ing-and-SE.htm

Your TE vario will indicate a gain when you are gaining. Some brave soul needs to fly into strong sink at high speed, push on the stick, and see if he can make the vario go up. I doubt a positive G optimized sailplane and human pilot can do this.





Evan Ludeman

i agree that it is unlikely that we would able or want to gain significant energy entering sink, but as you can see, an albatross gains energy from using the gradient without ever going negative. the article you reference by Taras, is the one i was referring to, just shows that with only sink (and dead air) you can maintain. something that is counter intuitive for sure.

if you flew the albatross path, the te would sing on both the climb as well as the turn in the "head wind" at the bottom of the path. perhaps what we are looking for is "energy neto"...

it seems we are looking to identify the places we could find this usable shear. it is plentiful near the ground, and best near rough terrain. what are the circulation patterns that might be exploitable where each pass is not a potential landing? was the JS1 flight working the sink near the edge of the street?


Rick