On Jun 5, 3:00*pm, John Cochrane
wrote:
If you aren't referring to dynamic soaring then all I can say is
"huh"?

No, Gary means it. In theory, we can gain a lot by strong pull ups and
pushovers in thermal entries and exits. In fact, in theory, you can
stay up when there is only sink. You push to strong negative g's in
the sink, then strong positive gs when you are out of the sink. Huh?
Think of a basketball; your hand is sink and the ground is still air.
When you push hard negative g's in the sink, the glider exits the sink
with more airspeed than it entered, just like the basketball as it
hits your hand. The opposite happens when you pull hard for the first
second or two after entering lift.

To work, you have to pull hard while the glider is still descending
relative to the surrounding air in the thermal, and ascending relative
to surrounding air in the still air or sink. You only get a second or
two. In my experiments I haven't gotten this to work, though it may
account for some of the aggressive zooming we see in Texas
conditions.

Really, to make it work well, I think we need to surrender pitch
control to a computer that handles pitch based on very fast update
vario and g meter. The optimal pitch control is not a hard problem to
solve. It does take a faster feedback than human -- or at least this
human -- can seem to manage.

Don't laugh. Handing over pitch control to a computer might give the
same performance boost as several meters of span. It would definitely
be worth it, though the occupant might need an iron stomach.

John Cochrane
BB

I was thinking more about this. I can see why as you approach a
beautiful cu you would push over as you enter the downwash around the
thermal then reverse and pull as you get into the lift. The tricky
part for me is that I rely a lot on the G sensation I get from entry
into lift to determine where to stop and circle. If I am pulling a lot
of Gs on top of that it masks the feel of the lift which means I need
other cues to ensure that I don't flail around looking for the core -
such as another glider already racked in tight or a very small cu to
mark the thermal.