Which Way is That Thermal?

I was sent a link to a gadget some college engineers-in-the-making
built. http://engenius.sece.rmit.edu.au/Abstracts/Page601.htm. It
tries to detect which way a thermal is based on temperature differences
between wing tips. Bright boys.

I have two questions;

1) Have there been other gadgets created to do the same thing? How
well did they work?

2) What do you use to determine if the thermal is on the left or the
right? This is the wing up or down when its near the thermal debate.

Thanks, John

It's an old idea. Past attempts have failed because the temperature
gradients were too small to be detected reliably. Perhaps modern
sensors will work better.

As for number 2, there's really no debate. For conventional gliders,
the wing that goes up points in the direction of the thermal. Flying
wings may be a different story.



ContestID67 wrote:
I was sent a link to a gadget some college engineers-in-the-making
built. http://engenius.sece.rmit.edu.au/Abstracts/Page601.htm. It
tries to detect which way a thermal is based on temperature differences
between wing tips. Bright boys.

I have two questions;

1) Have there been other gadgets created to do the same thing? How
well did they work?

2) What do you use to determine if the thermal is on the left or the
right? This is the wing up or down when its near the thermal debate.

Thanks, John

Regarding apparent rising wings, that may not indicate anything
regarding the direction of the core of the thermal, other than a turn
may indicated.

That is, there is another school of thought on which way to turn,
especially if the goal is to center as quickly as possible in a
thermal.

Frank Whiteley

wrote:
It's an old idea. Past attempts have failed because the temperature
gradients were too small to be detected reliably. Perhaps modern
sensors will work better.

As for number 2, there's really no debate. For conventional gliders,
the wing that goes up points in the direction of the thermal. Flying
wings may be a different story.



ContestID67 wrote:
I was sent a link to a gadget some college engineers-in-the-making
built. http://engenius.sece.rmit.edu.au/Abstracts/Page601.htm. It
tries to detect which way a thermal is based on temperature differences
between wing tips. Bright boys.

I have two questions;

1) Have there been other gadgets created to do the same thing? How
well did they work?

2) What do you use to determine if the thermal is on the left or the
right? This is the wing up or down when its near the thermal debate.

Thanks, John

Really? I had never heard of the "turn away from the thermal" school
of thought.



Frank Whiteley wrote:
Regarding apparent rising wings, that may not indicate anything
regarding the direction of the core of the thermal, other than a turn
may indicated.

That is, there is another school of thought on which way to turn,
especially if the goal is to center as quickly as possible in a
thermal.

Frank Whiteley

wrote:
It's an old idea. Past attempts have failed because the temperature
gradients were too small to be detected reliably. Perhaps modern
sensors will work better.

As for number 2, there's really no debate. For conventional gliders,
the wing that goes up points in the direction of the thermal. Flying
wings may be a different story.



ContestID67 wrote:
I was sent a link to a gadget some college engineers-in-the-making
built. http://engenius.sece.rmit.edu.au/Abstracts/Page601.htm. It
tries to detect which way a thermal is based on temperature differences
between wing tips. Bright boys.

I have two questions;

1) Have there been other gadgets created to do the same thing? How
well did they work?

2) What do you use to determine if the thermal is on the left or the
right? This is the wing up or down when its near the thermal debate.

Thanks, John

Yes, Frank, please explain this to us. I never heard that that there
was any other theory than turn toward the uplifted wing. Sure, there's
lots of theories about what to do after that. Bob Wander's "book" has
the 4-circle search method, and it seems like I read something in
Knauff's stuff somewhere, maybe in "Breaking the Apron Strings." I'm
still early in the learning process, and seem to have the best results
with "tighten the turn in decreasing lift, loosen the turn in
increasing lift. This works so well that I'm frequently seeing people
in roughly equal gliders climbing past me, so I'm always looking for a
better way. Enlighten us.

Thanks,
Ed

wrote:
Really? I had never heard of the "turn away from the thermal" school
of thought.



Frank Whiteley wrote:
Regarding apparent rising wings, that may not indicate anything
regarding the direction of the core of the thermal, other than a turn
may indicated.

That is, there is another school of thought on which way to turn,
especially if the goal is to center as quickly as possible in a
thermal.

Frank Whiteley

While cruising, one wing raises and the other lowers, left or right?
For discussion's sake, let's say the right wing's up and left wing
down. This can be caused by lift at the right wing, or sink at the
left wing.

When we have good thermal indicators in clouds, most of the time while
heading for that marker we encounter sink upon entering the thermal,
and sink again on exiting it on the next cruise.

So a down wing may well indicate that the thermal is just a bit further
in that direction. If you turn towards the raised wing, you may, as
Bill points out, also find the thermal about half the time, but the
thinking is that you've already flown past the core and will take two
or three turns to center. Or, you won't find the thermal, as it was
toward the down wing. By turning toward the down wing, you'll find the
thermal, or not. If not, you continue the turn through 270 degrees and
fly back to the raised wing indication which should be nearer the core
than if you'd originally turned that direction.

The concept is that you will reduce uncertainty in locating the thermal
initially and core more quickly at least half the time and that the
strategy saves 15-30 seconds or more per climb, or quite a lot during a
XC event. Perhaps a winning strategy.

Frank Whiteley
flying_monkey wrote:
Yes, Frank, please explain this to us. I never heard that that there
was any other theory than turn toward the uplifted wing. Sure, there's
lots of theories about what to do after that. Bob Wander's "book" has
the 4-circle search method, and it seems like I read something in
Knauff's stuff somewhere, maybe in "Breaking the Apron Strings." I'm
still early in the learning process, and seem to have the best results
with "tighten the turn in decreasing lift, loosen the turn in
increasing lift. This works so well that I'm frequently seeing people
in roughly equal gliders climbing past me, so I'm always looking for a
better way. Enlighten us.

Thanks,
Ed

wrote:
Really? I had never heard of the "turn away from the thermal" school
of thought.



Frank Whiteley wrote:
Regarding apparent rising wings, that may not indicate anything
regarding the direction of the core of the thermal, other than a turn
may indicated.

That is, there is another school of thought on which way to turn,
especially if the goal is to center as quickly as possible in a
thermal.

Frank Whiteley

flying_monkey wrote:
I never heard that that there
was any other theory than turn toward the uplifted wing.

Try doing that below ridge height.
Better yet, think about what happens if you would do that, and don't.
Jim

"Frank Whiteley" wrote in message
ups.com...
Regarding apparent rising wings, that may not indicate anything
regarding the direction of the core of the thermal, other than a turn
may indicated.

That is, there is another school of thought on which way to turn,
especially if the goal is to center as quickly as possible in a
thermal.

Frank Whiteley

Yup, if you always turn toward the lifted wing, I guarantee you will be
right at least half the time.

Bill D

Which wing tip goes up? turn that way. Finger tips on the stick.. feel the
pressure...
Use the Force Luke..

BT

"ContestID67" wrote in message
ups.com...
I was sent a link to a gadget some college engineers-in-the-making
built. http://engenius.sece.rmit.edu.au/Abstracts/Page601.htm. It
tries to detect which way a thermal is based on temperature differences
between wing tips. Bright boys.

I have two questions;

1) Have there been other gadgets created to do the same thing? How
well did they work?

2) What do you use to determine if the thermal is on the left or the
right? This is the wing up or down when its near the thermal debate.

Thanks, John

Suppose I'm flying along straight and level and I feel
the left wingtip rise. Where is the thermal? Is it
on the left and is it lifting the wing?

Or, is the right wing in sink and the wing is being
pushed down?

Does that mean there is a thermal further to the right
and the sink that pushed my wing down is the sink that
surrounds the thermal?

Which way should I turn?

For me, the answer is sometimes straight forward:
Turn the way my friends are turning because they got
there sooner than me!

Ray Lovinggood
Carrboro, North Carolina, USA

At 10:48 06 September 2006, Flying_Monkey wrote:
Yes, Frank, please explain this to us. I never heard
that that there
was any other theory than turn toward the uplifted
wing. Sure, there's
lots of theories about what to do after that. Bob
Wander's 'book' has
the 4-circle search method, and it seems like I read
something in
Knauff's stuff somewhere, maybe in 'Breaking the Apron
Strings.' I'm
still early in the learning process, and seem to have
the best results
with 'tighten the turn in decreasing lift, loosen the
turn in
increasing lift. This works so well that I'm frequently
seeing people
in roughly equal gliders climbing past me, so I'm always
looking for a
better way. Enlighten us.

Thanks,
Ed

wrote:
Really? I had never heard of the 'turn away from
the thermal' school
of thought.



Frank Whiteley wrote:
Regarding apparent rising wings, that may not indicate
anything
regarding the direction of the core of the thermal,
other than a turn
may indicated.

That is, there is another school of thought on which
way to turn,
especially if the goal is to center as quickly as
possible in a
thermal.

Frank Whiteley