Open Class

On Saturday, February 21, 2015 at 1:49:46 AM UTC-5, Bruce Hoult wrote:
On Saturday, February 21, 2015 at 5:09:07 PM UTC+13, Bob Kuykendall wrote:
On Friday, February 13, 2015 at 9:49:02 PM UTC-8, Bruce Hoult wrote:

...but they lose badly to the new thin airfoils at high speed...

It's kind of a nitpick, but there's really nothing new about thin airfoils. What has changed in the last decade and a half is the cost-effectiveness of the structure required to implement them in competitive sailplanes.

Sure, carbon spars enabled them.

Spars AND skins. Torsional stiffness is a big consideration in these structures.
UH

I owned a Jantar-1 many years ago. From the weight of each wing panel, I surmise that the main spar was a steel girder, probably a recycled railway line. Modern technology enables thinner, lighter, stronger structures (and no steel girders!)

Mike

On Saturday, 14 February 2015 00:29:03 UTC, Jonathan St. Cloud wrote:
I have been away from soaring for 12 years and have noticed the open class now has long wing and much shorter wing birds (JS-1C) competing. I am curious how do the 21 and 23 meter new ships keep up with the ASW-22BL's and Nimbus-4's. Are the new shorter wing gliders better overall (better L/D, better penetration ) or just better on strong days when wing loading counts more than the ability to stay in the air?



Of the long winged gliders the EB29 clearly outperforms the 22 and Nimbus 4.. I have no idea how good the ASH30 is. Claimed best L/D for the EB29 is 68, for the JS1C 21 is 60.

The best L/D of a glider is a meaningless number. It is just one point on the polar, and plus, it is at a point that we rarely fly. A better question is what is the L/D at 100 knots (185 km/h)? It's an even better question if we assume high wing loadings. Ultra long wings are only better above the plains in very weak conditions.

Chris

On Saturday, February 14, 2015 at 7:49:43 AM UTC-5, Fox Two wrote:
The best L/D of a glider is a meaningless number. It is just one point on the polar, and plus, it is at a point that we rarely fly. A better question is what is the L/D at 100 knots (185 km/h)? It's an even better question if we assume high wing loadings. Ultra long wings are only better above the plains in very weak conditions.

Chris

Really? When thermals die it is all that matters.

I had read where SH is no longer publishing polars for it's gliders. Anyone know the true polars of the JS1-C, Quintus and/or Anteres 23. Has any club or organization started doing the glide test that Dick Johnson for so many years provided the gliding community. I have been away from gliding for a while, much has changed. I have much time in Nimbus 4, Nimbus 4D, Nimbus 3D. I assume the shorter wing birds could get much more out of the thermal, but I would think the long wing birds would be better at dolphin flying. Any comments. Would love to hear from pilots that have flown in or against the shorter wing open versus the longer wing opens.

At 19:59 14 February 2015, Jonathan St. Cloud wrote:
I had read where SH is no longer publishing polars for it's gliders.
Anyon=
e know the true polars of the JS1-C, Quintus and/or Anteres 23. Has any
cl=
ub or organization started doing the glide test that Dick Johnson for so
ma=
ny years provided the gliding community. I have been away from gliding
for=
a while, much has changed. I have much time in Nimbus 4, Nimbus 4D,
Nimbu=
s 3D. I assume the shorter wing birds could get much more out of the
ther=
mal, but I would think the long wing birds would be better at dolphin
flyin=
g. Any comments. Would love to hear from pilots that have flown in or
aga=
inst the shorter wing open versus the longer wing opens.



It is all about the wing loadings!

On Saturday, 14 February 2015 02:29:03 UTC+2, Jonathan St. Cloud wrote:
I have been away from soaring for 12 years and have noticed the open class now has long wing and much shorter wing birds (JS-1C) competing. I am curious how do the 21 and 23 meter new ships keep up with the ASW-22BL's and Nimbus-4's. Are the new shorter wing gliders better overall (better L/D, better penetration ) or just better on strong days when wing loading counts more than the ability to stay in the air?

New shorter wing open class ship probably outperform these older ships easily, but according to few pilot friends that have flown latest open class comps think there still is no substitute for span. At Leszno one pilot flying new 23m ship thought that EBs ran better (plus Concordia, of course). I've seen calculations that shorter span ships can come pretty close when avg. speeds are very high, but not that much better even then, and 99% of comps have several days of pretty lousy weather that you really will have all the span you can buy.

Steve Leonard: When it comes to glider wings how much cumulative span do you own right now? :-)

The newer ships going to shorter wings and the advantages and disadvantages of doing so is something that fascinates me. Mind you, with the amount of money I have it's not something that will have any relevance to my buying decisions unless I win a lottery! Someday I hope to move from 15 meters to 20 meters by replacing my ASW-15 with an ASW-17 but that's about as far as I'm ever likely to be able to go.

The newer ships have a higher minumum circling speed and therefore need a
slightly higher level of skill to maximise climb rate but they go better at
high speeds. This statement has been true since the 1930's

At 09:01 24 February 2015, wrote:
Steve Leonard: When it comes to glider wings how much cumulative span do
yo=
u own right now? :-)

The newer ships going to shorter wings and the advantages and
disadvantages=
of doing so is something that fascinates me. Mind you, with the amount
of
=
money I have it's not something that will have any relevance to my buying
d=
ecisions unless I win a lottery! Someday I hope to move from 15 meters to
2=
0 meters by replacing my ASW-15 with an ASW-17 but that's about as far as
I=
'm ever likely to be able to go.