I dynamic soar in thermals and it hauls

[kewhite]

ive been soaring in thermals or next to thermals on a regular basis now ,with figure 8 swooping flight patterns and my glider a hauls and gets incredible boosts that shoot it upwards 100's of feet ive been doing this for about a year, theres even a slot to fly thru that shoots you forward like on the sides of thermals, i can see it going thru two types of air and it makes diffrent sounds,,really loud whistiling at times..there seems to be sevral ways to work this air from the sides and also down wind,my plane is usually downwind of where im standing. .clik here www.gliderworld.rchomepage.com

[Miami Mike]

I already offered my opinion of this (http://www.rcgroups.com/forums/showpost.php?p=2377568&postcount=6) when you posted about it on another forum. It'll be interesting to see what these guys think.

Nice looking plane.

[kewhite]

Why dont you just try it and see for yourself then report back youre observations,, try a day when its not windy and do it down wind .

[Miami Mike]

Why would I have to do it downwind? Why would my glider care where I'm standing?

[TheTick]

Doesn't look like that ship would survive any serious ds'ing, but sounds like your'e having fun.

[Foxy]

I swear i have heard of this before. My thinking would be that you are moving between the sink and the lift, this being the equivalent of moving in and out of moving and still air as with normal dynamic soaring. I may be looking at it too simplisticly however. I'm at a loss as to why the original poster would make up such a story and find it a little odd that people don't believe him. I wonder how the first stories of dynamic soaring on a slope were received by others?

All the best
Adam

[Miami Mike]

I swear i have heard of this before.You probably did, but from the same person.

http://www.rcgroups.com/forums/showthread.php?p=2329000

[Bud Morrison]

Get video :)

[AntonL]

:) :) :) :) :) :)

[kewhite]

Come to Dallas texas you can stay at my glider buddys house hes the one know if its dynamic soaring but it reallly makes my glider accelrate and i can climb faster this way than circling in a thermal by stair stepping it.

[wakumann]

Keith,
guess you have a lot of sun in Texas.
My recommenation: stay in the shade.
And you Super dooper high speed "Regent" Glider.
Some discounter sell it maybe for approx $150, must be really high tech and perfect for DS.
Make a Video to proof anything otherwise it's sounds just like a (bad) joke.



Cheers
Thomas

[kewhite]

Keith,
guess you have a lot of sun in Texas.
My recommenation: stay in the shade.
And you Super dooper high speed "Regent" Glider.
Some discounter sell it maybe for approx $150, must be really high tech and perfect for DS.
Make a Video to proof anything otherwise it's sounds just like a (bad) joke.



Cheers
Thomas
its not dsing on a slope its dsing a thermal its not violent in a thermal i have a witness Ken Churkey..my plane does just fine dsing a thermal it wont explode,,noit even close .And Wakman if you spent half as much time flying than sittiing on the net maybe you would figured out dsing or stairstepping a thermal by now causse its not that hard....

[Miami Mike]

All of this hilarious sarcasm is really cracking me up, but whenever you DS experts are ready to get down to business, I'm really looking forward to learning exactly why it's not possible to dynamic soar in a thermal.

[kewhite]

give the defintion of dynamic soaring ok? maybe its not dsing but it really accelerates my glider maybe it needs a new name okay? you going to ruin all the fun for everyone else who wants to try it?

[Sparky Paul]

All of this hilarious sarcasm is really cracking me up, but whenever you DS experts are ready to get down to business, I'm really looking forward to learning exactly why it's not possible to dynamic soar in a thermal.
The way I understand DS flying, there's a wave on the back side of a hogback ridge. This wave doesn't move around all that much, it's generated by the shape of the ridge. Ridges are fixed.
A thermal OTOH, is forced to flow with the prevailing wind, and the direction is downwind. Unless the thermal is composed of visible air, making multiple passes thru such a transient effect with any additive effect to the plane will have a low probability of success.
You -know- where the DS rotor is likely to be.
Alleging the same from a thermal.... :(

[SchiessCo]

Go to http://www.billpattersonart.com/dszone.swf, click on the first sailplane on the lower left, follow the links.

[Miami Mike]

But Paul, dynamic soaring can take many different forms. Read here (http://www.wfu.edu/albatross/atwork/dynamic_soaring.htm) about how albatrosses travel across the ocean.

[wakumann]

Keith.
your Quote:

...'And Wakman if you spent half as much time flying than sittiing on the net maybe you would figured out dsing or stairstepping a thermal by now causse its not that hard....



It's Wakuman, but tkx for the insult

You absolutely right Keith, normaly I don't take this time, but in your case reading so much nonsense and... in your different treads it's really annoying.

Based on other comments (and already closed treads) I'm not the only one to feel this way.


Read some other postings from you:

Quote: my glider seemed faster in a themal going straight than on any dams around here thats all we have is dams to fly off of in texas...) ,

and this is also a good one from you:

Quote:

any one notice a diffrence in speed from day to day around may and june?evn in lift my glider was slow today,last week it was scary fast....


Leave the rating to other forums users.
Also you publish soon a book about Thermal soaring, hope you find some informed Buyers.




BTW: I fly 'performance' gliders and electrics for over 20 years and get enough airtime. Your Regent (100" WS Obechi over Foam don't even has a spar) I wouldnt take it for free..(have to correct: would take it but only too donate it to a Beginner).


Cheers
Thomas

[kewhite]

whats youre point thomas? are you a thermal flyer? just wondering?and no other people dont have youre opinion they even posted diagrams showing my techniques and want to try it.,,

1. what did i say that nonsense ellaborate please.in detail..
2, my soaring guide is already being advertised this month.
3 i will have the video to show it soon..

[Sparky Paul]

But Paul, dynamic soaring can take many different forms. Read here (http://www.wfu.edu/albatross/atwork/dynamic_soaring.htm) about how albatrosses travel across the ocean.
.
Having on-board wet ware does help finding the differences in wind direction, speed, and temperature.
Us ground-bound flightless mammals can only guess where the wind is, which way it's going etc (except for JW. I've seen him see air!)... as we fly thru the various disturbances that comprise rising air, -unless- the disturbance comes from a large fixed object.. :) such as Parker Mountain.

[wakumann]

To get this all in perspective:
Keith promoted his (2 page) Book as per Quote below.
....FS How to Thermal - Information that Works

Ive read books on soaring,they didn't make it any easier they left out too many important facts and left you guessing.My information tells you what to do and more than that it shows you a way to do it without having to guess.My freind Ken Churkey is 62 years old and gets nervous alot, only flies polyhedral he's been using my technique for 1 year and has never switched back and says " youre right its easier this way".You will thermal I guarantee it , You will remain in the thermal and not lose it, and you will out to a tiny dot using this information, ( its not a book). I use this ,,
,,OK ..
Attention i have recently attached a tow hook on a (heavy)sig ninja slope soarer and i have specked it out off a high start using my technique,,and my technique doesnt need 114 pages of space,,its simple, and straightforward ..



money back guarantee.
7.95..pst paid ., ,cash ,check,money order

I also offer private instruction in fortworth Texas...any questions send a pvt message....
I guess it's time to get some private lessons to learn his special flying techniqs. Guess some Guys in Red Deer didn't read his advice otherwise they would be all WC's.
Personaly I think it's a rip- off or someone just makes Jokes.



below one of the reponses:

The title calls what he's selling “a book”. Two pages is a darn thin book in my opinion. That plus his evasive answers to my (and others) questions sure makes me think some thing does not ring true.
Why call it a book when it’s really just a two page fact sheet...
Let us keep up the standard of this forum...
Cheers
Thomas

PS:
Keith please don't pm me anymore, I don't think it is apropiate. If you have something to proof, please use the forum.

Cheers

Thomas

attached pic of one of my models which I would like to try Keith technics.

[Bud Morrison]

Let us keep up the standard of this forum...
Cheers
Thomas


Yes lets
Which I believe the topic was DSing in Thermals.........

[motorhead]

In his defense, it is possible to DS a thermal. All it takes is two air masses with different velosities. I am friends with Gary Osoba who does DS thermals in a full size sailplane. You can see some of his background here http://www.paraglideamerica.com/team/gary.html
We have discussed it some but not to the point that I understand it so I have not tried it yet.
Wakumann, I know you are trying to sell your thermal guide but you will have some skeptics untill you produce a good video or provide to the general public your technique. If you can find someone with a good F3f or F3b glider you will see a large increase in speed and energy retention with your techniques.
BTW, there is nothing wrong with sloping dams. :)
Mike

[1nk]

Wakumann, how many tournaments and x country races have you won with your special technique?

[wakumann]

@ Motorhead and 1nk:
Please don't mix up Names.

'Kewhite' ( Keith) claims to have the 'new' thermal technics and wants to sell his pamphlet.

I'm just critical what he is proclaiming.
2 other treads from 'Kewhite' in the Slope and Thermal forum were closed due to similar controversy.


@ Motorhead: I know the full size guys have these technics and use it specially in Alpine soaring. For Modelers with limited eyesight its (mostly) useless. Some big Models (1/3 scale and up) with varios can use it.
But don't think Kewhite is refering to this kind of Models.


Cheers
Thomas

Kewhite (Keith), as mentioned before and recommended by others please make a Video to proof your case.

[gouch]

you going to ruin all the fun for everyone else who wants to try it?

Try what? You haven't given out much info. I have learnt more from guys like daemon, sparky, motorhead and miami mike in your threads than you.
If people with the credibility of these fliers and others on this board can't understand your methods, how can a stooge like me?

Edit: I just found another thread in thermal that keith started, and daemon just may be getting to the bottom of it with some diagrams. That's if everyone isn't over it already.........

[Daemon]

The diagram in question is
http://www.houseofthud.com/rc/tech/thermal-dsing.jpg
(This diagram is not to be used commercially, BTW)
Red is rising air, blue is sinking air. Violet is the shear boundary
layer between the two. Dive in through the side of the thermal,
pull up in the core and exit the far side pointed upwards, roll glider
over, pull down against the sinking air and dive back into the thermal
gaining airspeed at the boundary layer again, pull up, rinse repeat.

The problem is.. it assumes you've mapped out the boundaries
of the thermal which is rarely that simple. Also while Keith says
"yes that's it" he then follows by saying that he flies a much
more horizontal pattern, doesn't roll the glider over inverted at the
edges, but just climbs up hard and then noses it over hard at the top,
turns around and flies a horizontal figure 8 instead of a vertical one.
Who knows if what I'm showing is really what he is doing. I'm not
convinced he knows what the mechanism really is.

ian

[windsox]

but reliably finding and staying in thermals while avoiding sink would be good enough for me. :eek:

[AustinTatious]

Daemon.. nice picture!

However I do not think that To DS what you ahve drawn, you need to roll inverted.. Yes that would extract more energy from the air but it is not nessasary.. a simpl wingover will still provide for the mechanism of DS to occur once entering the rising air.

Though not by Keith I have witnessed this happen... Many times in Handlaunch.. Most of the time it is not intentional but whn it happens it is quite obvious as the glider gains lots of speed and altitude un-proportional to the strength of the lift it was flying in ( Had it simply been "thermal turning").


I think its quite funny that some peopl ahve "ragged" On keiths plane... Hell if all I had was 150.00 I would probably buy what he has, It is a good plane with 100 inches of RG-15 and about a 70 oz AUW... He Flys EVERY day for the most of the day off of a small bungee launcher... He Is very capable of finding lift and keeping the glider up even with the High wingloading...

Wakuman.... dude.. Just because you fly "high performance gliders and electrics" that is no reason for anyone to see yoru side.. Ive seen a lot Ignorant people flying the most expensive equipment... funny how theyy like to use that to show their abilities.

I think I am Going to start another thread and give the explaination of DS that made me have a better understanding of what is happening. I think most people over complicate it....look for it im oing now!

Austin

[Daemon]

If you don't roll inverted when you hit the sinking air, then you're really
only extracting energy from every other pass through the shear
layer at the edge of the thermal. You should be able to gain
kinetic energy both exitting and entering the thermal. If all you
do is a wingover, then it's not much different than pump on
the frontside (which is a form of DSing in itself).

ian

[AustinTatious]

I dotn completely agree with that... In frontside pumping, the air is ( for the most part) uniform.. in this situation, you fly from some downwards moving air to upwards moving air. In theory if you were flying at Terminal velocity in the downwards moving air and then penatrated into the upwards moving air, you have gained more KE than a plane diving and pumping on the frontide of a hill. It can only Dive at its TV.

Also, I dont see how you call it Dynamiic soaring as by definition you must have 2 airmasses moveing in different directions and/or velocities.

From watching this it appears they simply change the Energy in the plane from Kenitic to Potential over and over again.. They could never exceed the TV of the plane flying like this.

[1nk]

I love how everyone thinks that they are aerodynamic scientist. I love hearing complicated explanations of scientific theories or facts from the ignorant and uneducated, quite entertaining I must say.

Peace out!

[Daemon]

Simple definition of DSing is, converting a relatively sudden increase
in airspeed into an increase in kinetic energy in the "inertial frame"
through the use of aerodynamic lift. All known forms of DSing fit
into this definition, from an Albatross flying across the ocean to,
tearing it up on the backside at Parker, to DSing the thermal pictured
above to pumping a small lift band into a lot of altitude.

As for pumping, the air is most definitely NOT uniform. If it were
uniform you wouldn't go higher with each pump. A good pump carries
you above the lift band. The vertical component of the air's
motion is greater the closer you get to the slope due to compression
(until you get down into the draggy region near the vegetation).
The best example of this is when you're standing on a nearly vertical
20-30 foot high slope with about a 15mph wind. The lift band will
only carry you up maybe 30-40 feet above the top of the slope,
but start pumping, and you can get much higher. When you dive
vertically down from the more horizontally moving air into the into
the lift band, the airspeed of the glider first increases normally
due to the dive yes, but the *extra energy* comes from the increase
in airspeed coming from the vertical component of the air rising up
the face. That's the "sudden increase in airspeed" needed to DS.
To make use of it, you pull up hard and convert that airspeed into a
change in direction and change in velocity in the inertial or fixed
frame of reference. During that time, the glider is accellerating
past the velocity it had acheived from the dive alone. It *has to*
accellerate, or there's no way it could not only climb as high as
the last pump, but go higher each time. Remember you're flying
an identical path at the bottom of the U each time, so it has to be
accelleration that carries you higher, not just slope lift.

The funny thing is that so many people learn how to do big pumps with
heavy planes but never think about where the energy is coming from.
It's all accelleration at the bottom of the U. It's sort of an open
ended DS turn because you don't have anything to bank off of at the
top of the U to turn it into a full loop, so the best you can do is
convert your sudden increase in kinetic energy into potential energy
(altitude) right away, before it dissipates as drag. Ultimately drag
is still the limiting factor to how high you can pump though. And yes,
you can actually exceed TV for a short time at the bottom of the pump.

Consider if you come down out of a dive so high that you *reach*
terminal velocity, then *any* increase in airspeed as you enter the air
that's blowing up the face, puts you beyond TV. If you do nothing, but
keep diving down the face, you'll burn that extra airspeed off as drag.
If you pull up, you can convert that airspeed into kinetic energy.

Another way to think about it is.. What if you dive down at the top
of a good DS ridge, and punch through the shear layer on the back and
pull up in the rotor (half a DS loop) and then go straight back up.
We've all done this at some time, and just because it's open ended
(pointed at the sky) doesn't mean that it's not DSing. There's still
a sudden change in airspeed which is converted to kinetic energy
and then that into potential energy. Pumping is the same trick,
just with a more mild shear gradient.

ian

[Daemon]

I love how everyone thinks that they are aerodynamic scientist. I love hearing complicated explanations of scientific theories or facts from the ignorant and uneducated, quite entertaining I must say.

Peace out!

Wow, thanks for that really useful informative contribution to this thread.

ian

[AustinTatious]

1nk,

You are so right.. ill stop trying to learn now.. why bo0ther learnign when others already know. Ill jst listen to them blindly and run around with my head up my arse....Thank you so much for settin me strait.

Sheesh

[AustinTatious]

During that time, the glider is accellerating
past the velocity it had acheived from the dive alone. It *has to*
accellerate, or there's no way it could not only climb as high as
the last pump, but go higher each time. Remember you're flying
an identical path at the bottom of the U each time, so it has to be
accelleration that carries you higher, not just slope lift.


I understand that the plane can pump out of the lift band, and I understand that it accelerates as it moves upwards (starts flying WITH the air) HOwever, there is no point where the plane gets a SUDDEN burst of kinetic Energy. Also, can you illustrate any situation where this would work if the air was not moving upwards?


A hypothetcal

Winds 30 Mph
gravitational TV of plane= 100mph

Now Lets say the plane is hovering at the highest point in the lift band it can, NOw it dives strait down to do a pump. Lets say it accelerates to TV of 100 MPH This means it is going 70 mph in relation to the Earth( assuming air is going vertical). NOw coming to the bottom of the U, it levels out and starts bleeding off airspeed.. Now it pulls up. IT had 100 MPH airspeed and this is still slowly bleeding off as the plane travles upwards.. However as it travels upwards, its speed (with refrence to the ground) is now increased due to a "tailwind" but its KE with refrence to the air has not increased and is being converted to Potential Energy whilst suffering losses from drag. So the airplane in the dive entered the bottom of the "PUMP"with X KE. There is no BOOST to increase energy to make the plane go higher.. However once the plane starts upwards, it is traveling upwards faster( with same KE with refrence to the air) than it was traveling downwards on the other side. It is flying from a startpoint of 100 mph airspeed, slowly bleeding it off, but traveling upwards at a earth, speed of 130 initially (as it starts upwards)

In this situation the plane will not be capable of exceeding TV. It is not Building energy by means of a wind gradient.

Thoughts?


Damn tis hard to tye this stuff out.. so easy in person! :(

[AntonL]

Ian and Austin - great discussion. Probably deserves its own thread on DS in pumps though, rather than leaving it lost in here...

1ink - you are making a naive assumption there in suggesting that people who post on physics/aerodynamics related topics on these forums are ignorant. We all have different levels of understanding, but there is a lot to be gained from these discussions for those who approach them with a constructive and open minded attitude.

Anyway, back to the issue at hand.

Austin - I think there is some confusion there on a few of the key principles. The velocity in KE = mv^2 is not airspeed. The frame of reference is the ground, so it is ground speed that affects KE. An increase in airspeed does result in an increase in the PE of the glider. But the glider doesn't get accelerated by a tailwind "pushing" it. It gets accelerated by the lift force of the wing, when the pilot pulls up elevator and the plane passes through the wind gradient. The resultant lifting force is comprised of both a centripetal force that causes centripetal acceleration (change in direction; a circular path) and a forwards force in that causes linear acceleration (increase in forwards velocity). This is possible because of the increase in air speed that occurs as the glider moves through air masses of increasing velocity in the wind gradient, which facilitates the required AoA to maintain these accelerating forces during the 'pump' part of the pump. :)

Anton

[AustinTatious]

Anton...

I dont agree.. I think you have to measure the KE with refrence to the body the glider is moving within.... The glider may be moving around the earth, but it is Within the body of air.

IF you think about what happens during a pump, you will see that the glider flys thru Much less air molecules on its upswing. This means less drag per distance travled which is why it can go higher than the lift band.

[Daemon]

Anton...

I dont agree.. I think you have to measure the KE with refrence to the body the glider is moving within.... The glider may be moving around the earth, but it is Within the body of air.

You can disagree as much as you want, but you'd still be wrong about
the KE bit. Explained in the other thread. ;)


IF you think about what happens during a pump, you will see that the glider flys thru Much less air molecules on its upswing. This means less drag per distance travled which is why it can go higher than the lift band.

That's almost the craziest explanation for pumping that I've ever heard.
Fewer molecules of air going up? There's more molecules of air
going down then.. zero sum total.

Look, just *watch* a glider when the lift really turns on right
at the lip (I know you don't have many hills with real "lips" in TX) and
you pull up hard in the pump. It accellerates like a bat out of hell. It's
going *faster* at the exit of the bottom of the U, than when it
entered. You can choose to not believe this too, but I know it to
be true. It's obvious, just watching it, and it's totally consistent
with a rapid increase in airspeed as the glider drives down
into the lifting air, and then converts that to an increase in KE.
Might be able to pick it up on a radar gun if oriented just right.
(they'll read it going away as well as coming)

We're still talking pumping in this thread btw, because
I think a lot of Keith's thermal DSing is related to
just pumping the core of the thermal, especially if you
don't actually roll over and pull against the sinking air.

ian

[AntonL]

Look, just *watch* a glider when the lift really turns on right at the lip (I know you don't have many hills with real "lips" in TX) and
you pull up hard in the pump. It accellerates like a bat out of hell. It's
going *faster* at the exit of the bottom of the U, than when it
entered. I've seen this happen many times. In fact I've even seen my Weasel Pro do it on a little 20-30 foot slope! The difference in speed between entry and exit points of the bottom part of the "U" is quite amazing. Seems to work best when done as close as possible to the lip...which also seems to make it a somewhat risky exercise with bigger heavier gliders... :)

Anton

[AustinTatious]

How can you not agree that the Glider Actualyl Flies thru less air going up than it does going down?!?!?!

It is SO obvious!

I di dnot Say it flies thru less airspace.. Only that it fly's "BY" (if you will) fewer air molecules. When It goes up it has a "tailwind" and when it goes Down it has a "headwind" Its simple... It travles the same distance physically, but Less distance thru the air when it is going UP!

Of course it accelerates in relation to the ground when you pull up.. it goes from a state of headwind to a state of Tailwind!

there is nothing "crackpot" about this.

[AustinTatious]

Ok imgaine this... The glide has a TV of 100 mph

The air is blowing Strait up at 80 Mph. On the downline, the glider is only going to be traveling at 20mph in relation to the ground.... HOwever once it starts going upwards... Its speed will increase from 20mph to 180 mph.. and then start bleeding off...

This is VERY simple and you are telling me it is Ubsurd?

[AustinTatious]

It's obvious, just watching it, and it's totally consistent
with a rapid increase in airspeed as the glider drives down
into the lifting air, and then converts that to an increase in KE

If you put a Pitot tube on that plane, You arent going to See ANY rapid increase in airspeed... it is going to gradually increase and decrease as the glider goes up and down... Jsut as if it flew the same path in still air loosing altitude all the while.

BAsicall lets say you are flying from a platform that is falling... this provides a similar situation (exept that there is no end to the "liftband" because ALL of the air is moving strait up in relation to you). FLying the same "U" shape would give the same type of effect as standing at a ridge. The glider would "accelerate" when you exited the "u"

[kewhite]

The definition of Dynamics is the study of motion isnt it? i think dynamic means movent as opposed to static(not moving).. so all soaring is dynamic soaring in my opinion..

So when is someone going to try it? i did it again on monday.

[KingOfTheHill]

video, video, video, video, video, video....

another one of your posts said you glider weighs like 5 pounds!... how are you getting it up there to begine with? you must be hitting some HUGE HUGE earth shattering thermals

JOe

[Daemon]

This is VERY simple and you are telling me it is Ubsurd?

Yep, I'm telling you it's absurd, because the positive and negative
influence of drag all adds up to zero. Net zero effect.
If what you were saying were possible then you could accellerate
simply by flying around in circles (a circle relative to the ground)
in the wind, "because you'd accellerate when you have a tailwind".
In your scenario, the lessened drag while flying up, is exactly
opposed by the increased drag while flying downward.

Now back to your mythical uniform lift band. That is totally
wrong. You know the lift band doesn't look like that. There has to be
a wind gradient for slope lift to occur. What you're proposing is that
the slope lift is uniform and extends straight upwards forever.
That's impossible. It would require that the hill displace
all the air in front of it by it's own height from the ground to
space. Every hill, everywhere, all the time.

Here's a quicky representation of a small steep lift band.
http://www.houseofthud.com/rc/tech/RC-pumping.gif
I didn't have the time to show relative wind speed with different
length arrows and the compression is pretty loose but it works for
a very small steep hill (bigger hills have lift bands that extend
further out and higher).

The wind is compressed and accellerated upwards near the lip of the hill.
On a steep enough slope the air is moving almost vertically
near the lip so much so that it creates a rotor right behind the lip.
(which you can DS btw)
The lift band is not uniform from top to bottom, and its top boundary
is marked by the point at which the vertical component of the air's
velocity is simply not enough to support a glider in level flight, or
the horizontal component is large enough that the glider can't
fly forward against the wind in level flight. It is however possible
to pump it up well beyond that point, if the lift is strong at the lip.
Since the glider can fly an *identical* path at the bottom of
the U every time, and yet go higher every time, it has to be
accellerating at the bottom of the U, in order to carry it higher
each time beyond the top of the lift band.

Now about the "It has to exceed TV to be DSing" (which is wrong btw..
lots of things DS without exceeding TV including the albatross), that
is easily acheiveable here. The blue line shows the path of a glider
coming down vertically from a high pump. If it acheives TV high in
the lift band, then by the time it reaches the lip, it has exceeded it,
can accellerate at the bottom of the U and return to its original height
or higher. It's not a smooth increase in airspeed due only to gravity
(as you contend) because it's going straight down and the deeper it
goes into the lift band, the more the air is going upwards due to
slope compression. It can't all be going upwards forever, so
there must be a vertical lift gradient. It's not as sharp a gradient
as if it you flew it over the backside of a ridge crossing the shear
line and made a single DS turn followed by a zoom (do you deny that
that is a DS turn?), but it's still a wind gradient with energy extracted
from the sudden increase in airspeed just the same.

ian

[AntonL]

DS turns (whether at the bottom of a pump or not) involve a centripetal force and this force is responsible for the change in direction (i.e. circular path), but not the increase in ground speed. The centripetal force causes the constant adjustment of AoA as the glider goes around the DS turn and through the wind gradient/s. However, the lift vector comprises both the centripetal acceleration force *and* the linear acceleration force (relative to the ground) and it increases in magnitude as the wing passes through wind gradient.

Anton

[AustinTatious]

I dont believe ever said a plane HAS to exceed TV to be dsing.. if I did.. I apologise... I know that is not true....

about flyign thru less air...

2 planes are flyign opposit directions... one starts at point A the other at point B.

The wind is blowing from Point A to Point B

The aircraft going from Point B to Point A will fly thru more air and require more energy to make the same trip.. be that Fuel or Altitude.



ohh and

because the positive and negative
influence of drag all adds up to zero. Net zero effect

Sorry, they dont ...

If a plane flys from A to B and back again in ANY amount of wind... The energy and Time required to do so increases from what is required to do so in 0 wind

This is FACT!

[Daemon]

If a plane flys from A to B and back again in ANY amount of wind... The energy and Time required to do so increases from what is required to do so in 0 wind

This is FACT!


And how exactly does this help your case? It does exactly
the opposite. You've just said it takes more energy to make a round
trip in wind. A pump, down and back up to the same point is a
round trip from A to B and back to A. I've been telling you where the
energy to overcome the increased drag comes from. It's the transition
into and out of the air with the greater vertical component. In other
words, a change in airspeed, converted into accellerate via
the airfoil, or.. DSing.. ;)

ian

[AustinTatious]

Nice picture of the lift band....


HOwever you STATE that ther eis a RAPID increase in Headwind... However the diagram shows that there is a Slo steady increase in headwind.... The glider for sure is not going to exceed the TV by the windspeed. As it gets lower, the wind SLOWLY increases V , which in turn increases drag and slows the glider. The driving Force is still Gravity....

Assume a Body of upwards moving air that is moving upwards faster the lower you get.

At the bottom it is moving upwards at 100 mph and at the top it is not going up at all this increase is exponential..

Drop a glider from the top and dive strait down. IT will accelerate to TV thru the air and as it encounters the faster air, its decent will slow until it reaches the air moveing upwards at its TV. Then its decent will stop.

[AustinTatious]

And how exactly does this help your case? It does exactly
the opposite. You've just said it takes more energy to make a round
trip in wind.

It helps my case because it shows without a doubt you need more energy and time to fly into the wind...

If you fire two bullets in opposite directions, one into the wind and the other downwind, guess which one is going to go further... NOw lets say you fire both upwards.. but one goes thru air moving upwards at 30 mph.... guess which one goes higher?


In the case of the Diving airplane in a lift band....I am more concerned with The TIME it takes.... It flys down with a GS that is IAS - Headwind up with GS= IAS+ Tailwind

[stevef]

Austin, you're spot on. I had a device in my plane which measures altitude in relation to time. Also put in a device to measure airspeed. After a flight, we can download the data to our laptop for analysis. We also had a radar. The logs show that the airspeed is relatively similar, say on level flight going into the wind and with the wind. However, the radar shows a faster reading going downwind.

[ACM]

the radar shows a faster reading going downwind.

Because that was your ground speed.

[contest 2004]

Why did you delete my posts in "9/11-Incredible video with facts!" thread.
Are you afraid of those who say the truth?
Do you prefer to live in a lot of lies?

You say I must follow the rules, but also SPARKY PAUL and MATTLARSON29 don't follow the rules, THEY continue to post only in "Life, The Universe, and Politics" and you say nothing because THEY ARE great conformist.

Thank you for your warm welcome.
Contest2004

[wing warrior]

i say a video is in order! :D

[m_acree]

ive been soaring in thermals...
Is an apology in order for Mr. kewhite?

A relatively new thread posted by Z06kal references an article where full scale gliders are doing what kewhite claims he is doing.
http://www.rcgroups.com/forums/showthread.php?p=3147886#post3147886

Interesting DS article from Science Daily
http://www.sciencedaily.com/encyclopedia/dynamic_soaring

[ejett]

Well, I have resisted putting my two cents in on this issue through about 4 different threads I have read here and on RCU.

But, I feel like I must make some comment now. If a Full Scale sailplane can DS a thermal, then it is possible for a smaller RC sailplane to do so as well. Since, there has been ample evidence in this thread that it is possible with full scale and that appears to have been accepted by most that have replied here, I think that Keith has been able to "figure out" how to take advantage of the differences of the upward moving air and the downward moving air associated with thermals, whether or not others choose to believe him.

It seems to me that Keith, not being well known, is being unfairly dismissed in this matter.

m_acree: I personally think you are correct and Keith is owed an apology.

Keith has some information that he would like to disseminate and make some money on. It is an enterprise and the market will determine whether or not the enterprise is successful. If the enterprise is not successful, that does not mean that the effects that Keith has seen and been able to exploit are not real.

EJ

[Miami Mike]

Interesting DS article from Science Daily
http://www.sciencedaily.com/encyclo...dynamic_soaringThat link is broken. When you copy a link with a string of dots embedded in it you have to right-click it, select "Properties", and then copy the URL from that.











.

[m_acree]

That link is broken. When you copy a link with a string...Thanks, the link has been fixed.

I'm sure you want to read the article so you can be the first to offer a much deserved apology.

[jrerickson]

I hadn't been following this thread, but it does have an interesting history! In my experience you can do something similar to DS in a thermal, but it is not nearly as defined as DS on a slope. The first problem is that the thermal is constantly changing shape so the "boundry layer" is not well defined. You can extract some energy from "banking" off the rising column or air, but I'm not sure you get any more net altitude than by just coring the thermal! You might be going faster and banking harder, but a plane in the core of a thermal will probably out climb you.

[dephela]

Roger That jrerickson!
It's very easy to stay aloft using a thermal without being in it all the time. One can even speed up and still climb, but you give up a bit of the climb. Hey, you can do that in a thermal without even DS'ing! Same thing, you just give up a little of the climb rate.

Dennis

[KingOfTheHill]

if this was possible and even FUN or you could get ANY fun speed involved, there would be video's and more reputable people saying they DID it besides KEWHITE who edits EVERY SINGLE POST HE EVER WRITES!

he's annoying, let this thread DIE

JOe

[Soar_dude]

You would need some sort of variometer so that you when you where moving from lift to sink moving in and out of the thermal. I do not think you could do it by watching what the sailplane was doing and still be able to utilize the technique efficently. When you DS a slope you know where the boundry layer is at. When trying DS a moving airmass you have no point of reference between the sink and the lift. Horizontal DS is possible but again you have no point of reference. You need some sort of telemetry from the sailplane to know when you are moving from a higher velocity layer to a slower velocity layer.

Soar Dude

[invictarocks]

You need some sort of telemetry from the sailplane to know when you are moving from a higher velocity layer to a slower velocity layer.

Soar Dude


Wow. As with anything "new" people have definite opinions of what other people are capable of based on thier own apparent limitations. Not that I could neccessarily tell when MY plane was going in and out of the two airmasses, but I wouldn't say that Noone ever could.

Anyhow - The first thing I thought of when I figured out slope DSing was, "Hey, I bet you could do this flying in and out of a strong thermal!"

Have fun guys, and hey JOe - thanks for keeping this thread alive, I musta missed it the first time around!

(I'm kidding JOe, relax!)

[KingOfTheHill]

LOL, i didnt bring this up.... haha, someone else did, i was glad to see it gone... besides, KEWHITE hasnt even logged on since november 18th.... i dont think he cares anymore either :) hahha

JOe

[Miami Mike]

Thanks, the link has been fixed.

I'm sure you want to read the article so you can be the first to offer a much deserved apology.No, the link has not been fixed. It takes you to a "Help Page" that says, "The page you are looking for may have moved or is currently under construction."

And no, not a single one of my posts in this thread requires an apology, regardless of what this mysterious article, if indeed it exists, has to say.

[wakumann]

someone else did, i was glad to see it gone... besides, KEWHITE hasnt even logged on since november 18th.... i dont think he cares anymore either hahha


Hi Joe,
he's still around just changed twice his name.(aka Gliderworld, PROInstructor4)

Cheers
Thomas

[Miami Mike]

It makes sense that PROInstructor4 could be KEWHITE, considering the comment from KingOfTheHill that KEWHITE edits every post that he writes. I remember that this post (http://www.rcgroups.com/forums/showthread.php?p=3192854&postcount=13) by PROInstructor4 originally had a crude drawing of his goofy idea to fill in an RG15 airfoil with putty, as well as a comment that the whole thing was suggested to him by a race car driver. Now those parts of the post are gone, and the reason for editing is given as "added thoughts".

[Foamyfoam]

Moderator's edit:

From The Rules (http://www.rcgroups.com/pages/rccommguide/) located at the bottom of every page:
"There shall be no name-calling or other forms of ad hominem attacks.
Users shall not provoke one another."

Shall we remember this, guys? It would be the good thing to do. ;)

mw

[Soar_dude]

Wow. As with anything "new" people have definite opinions of what other people are capable of based on thier own apparent limitations. Not that I could neccessarily tell when MY plane was going in and out of the two airmasses, but I wouldn't say that Noone ever could.


I did not say it could not be done I just said to use the technique efficently. I know my own limitations. But from what I have seen and have read in this forum and magazines I understand how Dynamic Soaring works.

Soar Dude

[John Kim]

M Acree is right. When I read "Full Scale DS" article in Science Daily as quoted by Zo6kal, I thought it was credible (except that the full scale pilot might have ended up with a full scale headache after DSing at such a speed) and I wanted to know if any model pilot had similar experiene in my response. I did not know KEWHITE had posted on the subject already before.

At first, I thought the full scale pilot was using thermal for DS (vertical DS) like Kewhite but upon rereading the article, I realized that the full scale pilot was using the boundary between horizontally moving high velociy air stream above and a stagnant air mass below it. Whether it is vertical or horizontal DS, I wanted to try it myself but so far I failed because, like Soar dude mentioned, it is hard to define the boundary with no point of reference, although it is easier for a full scale pilot with variometer. But I will keep trying. Getting acceleration from the wind is fun and it will add a zip to slow thermal flying. I would like to hear more success stories.

[bbreidenbach]

not the best method for max agl but i have found myself flying in tilted orbits in a strong tight winter thermals. the plane was gaining altitude and seemed to be flying at much faster airspeeds . strange things happen , I was reading a book about full scale wave flying . the pilots were flying in " reflected energy wave " lift over the ocean, down wind of mtns off the coast of IRELAND . I wish i could remember how far but it seemed like an un-beliveable distance,like half-way to NORWAY !! chew on that!

[biber]

Don't mix up wave flight with dynamic saoring. That's two different pairs of boots. Nevertheless waveflight is absolutely fascinating but not likely to be carried out with RC-models because wave lift is seldom found close to the ground. Unfortunately there are very gusty high energetic vortices below waves (don't know the english term for them, in german they are called 'Rotoren' since they are rotating) wich are quite uncomfortable to full scale glide in. The good thing about waves is that they sometimes reach up to several kilometers altitude far more than any thermals and above the clouds the air is absolutely smooth in contrast to close to the ground.

biber

[John Kim]

biber,

Two different pairs of boots? ha, ha.

I always wanted to ride a full scale glider and experience myself the exciting ridge wave and thermal flying, but I was too chicken to go up myself. I only dream about it when I read glider books.

Do you fly a real glider? I know glider flying was most active in Germany before the war when Germany was prohibited to build powered aircrafts under Paris Peace Treaty imposed after WW I and many German youths took part in glider training. I received such a basic training when I was a high school boy in 1944, using a German designed wooden framed glider (I don't remember the name). The maximum height I flew was 1 meter during take-off training. We were forbidden to go up any higher. Soon after that, the war ended. If the war lasted longer, I will probably ended up in Kamikaze attacks.

[bbreidenbach]

wave ,different boots but the same ( soul ) sole. dynamic in the sense of unusual extraction of energy. california altitude record is frozen for safeties sake at approx. 49,000 ft . one record was set in 1952 in a PRATT-REED. sailplanes have been broken apart in a rotor . the DS guys are aware of rotor !! I have flown flat land thermals in a ASK-21 with instructor and also with a friend , if you get the chance JUST DO IT, now I am always looking up ! I have seen my rc-plane fly thru turbulent air (rotor) at the perimeter of strong thermal lift, tipping the plane so much that i ended up flying in some sorta, kinda DS'ing . keep looking up with your chin high !! pictures from NEW ZELAND , no thats not me.

[biber]

Yes I do full scale gliding too. Sadly had not much opportunity to do it in mountains waves,(only one flight with Ingo Renner in the Italian Alpes) but there even occur waves in flat land without any mtns under some special circumstances. Anyhow, most gliding I do is aerobatics :D , not much about distance ;) .

[bbreidenbach]

biber, i sent you a private message.see if you can help.

[katobaggins]

When I first started flying thermals, I got into what I thought was a very powerful one. The odd part of it was that it was stationary even in the 15-20 mph wind that was present that afternoon. I was up about 1000' -1300'. After flying this "thermal" for 10-15 min I was thought perhaps I was riding some ridge lift from a tree line that was some 300-400 yards up wind as my circles turned into a back and forth flight path. The trees are only 50' or so tall so this didn't quite make sense to me.

I was flying this "tree ridge" for about 40 mins when a kid that I know showed up and asked if he could fly it. I had altitude to spare so I handed the TX to him with some instructions (he'd never flown before). After about 3 mins he had goofed enough turns to bring in down to about 600'. Overall he'd done a good job for his first go. I took the TX back and started the back and forth pattern again. I was soon back to 1000' plus. After an hour and a half or so my neck was getting stiff and the sun was was getting lower so I decided to call it quits.

Reflecting back on it now, I believe that I had managed to get into the wave on the leeward side of the 500' hill that's up wind of the field that I fly thermals on. I think what happened is that I managed to ride a thermal into the base of the wave and then stayed there for the rest of the flight. It's the only thing that makes sense.

[d.s.stunner]

Cool,

If the liftband was wide and smooth and stationary that would make sense. If the air 500' and below was super turbulent that would also indicate that you may have been in wave lift

Ryan

[gliderstuff]

This is my machine....it has like more 300 flights maybe 500?
I dunno Austin and Steve really kid me alot and ask me how it flys with so much tape on it.

Actual true circle Dsing is next to impossible with any real speed.

[Miami Mike]

Oh no, not again! (http://www.rcgroups.com/forums/showthread.php?p=2498919&postcount=4)

[Nico Peursum]

I have studied DS in a thermal years ago. The theory is that, when passing throug a thermal, you apply negative-g when crossing through the sink area and positive-g when crossing through the lift centre. It works well on the computer, but you have to know the exact size and position of the thermal :rolleyes: which is a bit difficult in real life.

[gliderstuff]

This is for the comment above..its easy because once your nose is pointed downwards for a second or so then your applying some back stick thru a U shaped swoop.

[gliderstuff]

Not real fast but here it is. This was without much of a diving entry. I wasnt really thinking about speed at the time. If you start off higher and dive longer then you can do the U shaped swoops and with a great deal more speed. Whatever is going on I like doing it.

http://smg.photobucket.com/albums/v213/gliderworld/?action=view&current=dsclip.flv

[Miami Mike]

Whatever is going on I like doing it.Yes, it's called thermal soaring and the rest of us like it too.

If you're wondering why your plane speeds up, it's because you're pointing the nose down. :rolleyes:

It's a decent video though.

[gliderstuff]

Here we have a more horizontal flight. I was the pilot so I know where the sink was. Look closely just after the final left hand turn. This is where the sink was when I was flying youll notice an sudden acceleration even after the glider is level.

http://smg.photobucket.com/albums/v213/gliderworld/?action=view&current=scisorclip.flv

Also when doing large swoops and rolling at each end you can do multiple passes without losing any altitude. Also if you dive from any heigth you can't get higher than where you started without help or that would be perputual motion. And Im flying in the sink not the lift.

[AustinTatious]

Ian,

I'm still right :-P

[KingOfTheHill]

Go Away!

[AustinTatious]

Go Away!

NEVER!

[gliderstuff]

What?

[schrederman]

In all of this diatribe, there isn't one word about the ADVANTAGE of this. I have seen reports about some of the world's best full-scale pilots DSing in thermals. The over riding theme is that it NOT worth the trouble. If you truly core a strong thermal, you will have a much greater net gain in the same time period as all this draggy flippin' and floppin' around. By truly coring a thermal, I mean not riding the 2-knot fluff around the outside, but crankin' and bankin' with the stick on the back stop, pulling 2 Gs most of the time. Full-scale sailplanes are limited in airspeed and stess... Mine is one of the stronger ones ever made and I'll take the core-the-thermal trick over this any day.

C'mon, man... you're givin Ft. Worth a bad name... and Texans, too...

Go down to TSA, just south of Midlothian, and ask if you can take their new ASK-21 for a thermal - DS ride and see how fast they run you off... It'll be an adventure. By the way, DON'T tell 'em I sent ya...8^)...

Jack... from Ft. Worth...

[gliderstuff]

First youre right not much advantage in fulll swoops but lots of fun. However I have seen an advantage on occasion at about 130 pm by using the Stair Step method in a figure 8. I alternated back and forth between the stepping and just circling and with this paticular thermal it was making quick healthy leaps by stepping it that just could not be duplicated by circling. Also at the end of each step the new cycle was started without losing the previous gain whatsoever.

Keith- Arlington

[quigley257]

Sounds so easy a caveman could do it.... :rolleyes:

[davidjensen]

I don't think there is anything DYNAMIC in the thermal flight on the video. DS is all about acceleration and good old SPEED.

[mattJ]

But Paul, dynamic soaring can take many different forms. Read here (http://www.wfu.edu/albatross/atwork/dynamic_soaring.htm) about how albatrosses travel across the ocean.

yeah Mike,

Dsing is nothing more than trading different forms of energy. All you need is a gradient and then you can trade speed/inertia for altitude. Dynamic soaring was discovered many tens of thousands of feet above ground in wave lift like the albatross. Turkey vultures do it all day long flying in the most turbulent and eddied air.

Dsing in or around thermal gradients and sheer is perfectly plausible if not pretty difficult to pull off. Again, watch Turkey Vultures.

It's kinda like when people ask me "what makes your glider stay up?" I say, "gravity...you know the weak force".

[Flying-Addict]

Keith, now that you changed your handle back to ProInstructor I realize who you are...(Once I saw this my first intentions were to kind of rip on you here, but after pulling the cd out that I bought from you, which I thought I had thrown away actually, I watched it again tonight and I came to a conclusion--read on:)...

I bought your CD when you had if for sale for $10 bucks...I thought, "what the heck, I want to see what this is about." My low expectations were realized though. The production quality was pretty bad and it was kind of short, BUT, I realized that it does look like you were having fun using this "unorthodox" method of thermaling in the video and I have to say, it is an interesting style of flying.

I have to agree with schrederman. I think coring and circling it up is much more effective without a doubt--but that just may not be your speed ;). I really couldn't see you gaining much altitude using the "ds" method in the video, but it was interesting nevertheless and it kind of looked fun to rip around in the sky like you were doing--just basically keeping airspeed up. I think the high winds that you were flying in and a heavier wing-loading helped raise the "fun" factor up as well. I may give it a go tomorrow just to try it out for fun.

If I can increase my flight times I'll post back with the good news...I'm not holding my breath though.

I personally don't think there's anything wrong with trying to think-outside-the-box, like you're doing here. That's how these new methods of flying come about. I think it's all going to come down to what works for you and how to keep it fun.

F/A

[gliderstuff]

Keith, now that you changed your handle back to ProInstructor I realize who you are...(Once I saw this my first intentions were to kind of rip on you here, but after pulling the cd out that I bought from you, which I thought I had thrown away actually, I watched it again tonight and I came to a conclusion--read on:)...

I bought your CD when you had if for sale for $10 bucks...I thought, "what the heck, I want to see what this is about." My low expectations were realized though. The production quality was pretty bad and it was kind of short, BUT, I realized that it does look like you were having fun using this "unorthodox" method of thermaling in the video and I have to say, it is an interesting style of flying.

I have to agree with schrederman. I think coring and circling it up is much more effective without a doubt--but that just may not be your speed ;). I really couldn't see you gaining much altitude using the "ds" method in the video, but it was interesting nevertheless and it kind of looked fun to rip around in the sky like you were doing--just basically keeping airspeed up. I think the high winds that you were flying in and a heavier wing-loading helped raise the "fun" factor up as well. I may give it a go tomorrow just to try it out for fun.

If I can increase my flight times I'll post back with the good news...I'm not holding my breath though.

I personally don't think there's anything wrong with trying to think-outside-the-box, like you're doing here. That's how these new methods of flying come about. I think it's all going to come down to what works for you and how to keep it fun.

F/A

Yea its fun...

[Captain Canardly]

I would understand dynamic thermaling as using secodary control surfaces to play in the waves amd rivers at airspeed enough to overcome the weight!- we've been in waves for 15 minutes on a 1mile square sod farm, and the wave livked by an irrigation ditch!
Johnny

[mattJ]

Thanks for sharing this technique Pro4. I know you caught some crap from some folks but I've already found it useful. There is a farm house at the edge of my field with some tall trees and a large barn with a black roof. It's what hang glider pilots call a house thermal not because it's a house but because it's always there. Very predictable but it's just a bump like you may encounter flying over a narrow street. The heated volume isn't enough to punch through the surrounding mass but it's very buoyant and turbulent air. I watched another pilot keep getting suckered into circling the spot like it was a normal thermal. The bump only tops out 50' above the trees (sounds like slope lift on a treeline but it's not given it's there no matter wind direction or velocity). I remembered the video clip and I worked it with DSing in mind and was able to use that spot to stage my thermaling. I would run to the area when I encountered sink in the field and was able to maintain a good hundred feet above the bump occasionally flying out to look for real thermals. I had 20min flights without getting more than a couple hundred feet off the ground.

Remaining in the air is always better. By flying that bump with this technique (well at least my lame version of it) I was able to fly quickly over to thermals that were being indicated by vultures and I had the best gains and duration of my rc soaring career to date; a couple grand and thirty minutes twice and many other good flights.

Thanks

[tonyestep]

For those who wish to find out what dynamic soaring actually is and how it works, this issue of RC Soaring Digest has an excellent article, explaining the physics of how a plane or bird can extract energy from the wind gradient behind a slope or over certain types of terrain. It can be found at:
http://www.rcsoaringdigest.com/pdfs/RCSD-2007/RCSD-2007-07.pdf
Needless to say, there is no mention of dynamic soaring in air where there is no gradient.