Why is there nothing better than a Discus 2a?

[Paul T[_4_]]

The Discus 2 is now well over 15 years old - why is there nothing better in
Standard Class? Has glider design reached a plateau in terms of performance
in the Standard Class?

[[email protected]]

On Friday, January 3, 2014 2:24:27 PM UTC-5, Paul T wrote:
> The Discus 2 is now well over 15 years old - why is there nothing better in Standard Class? Has glider design reached a plateau in terms of performance in the Standard Class?

Nobody is buying new Std class gliders, in part because it is a quietly shrinking class.
There is no market incentive for manufacturers to develop a new glider, especially when they can put their effort into the popular 18 meter gliders that the wealthy glider buying class seems to want while generating susstantially more revenue per sale.
For racers, this is actaully a good thing because there are plenty of D2's,28's LS-8's, etc that can be had reasonably and allow a pilot to be competitive.
One view
UH

[Peter F[_2_]]

Same is pretty much true in all the "smaller" classes

15m class there's not really anything "better" than the V2a or ASW27, both
of which are pretty ancient designs

18m class, the new kid on the block is the JS1, the V2cx & ASG29 are still
pretty close - JS1 has "Open class" option

The newest gliders seem to be appearing in open class. But Schempp &
Schleicher has now produced their offerings.

2-seat XC class seems stable with the Duo, Arcus & soon ASG32

Not sure I'd want to be starting a career in glider design right now.

The only opening I can see is for a competitor for the K21
Relatively low cost, strong, reasonable performance, fly the whole training
curriculum including spinning.
A bit like the fixed wheel DG1000

PF


At 20:16 03 January 2014, wrote:
>On Friday, January 3, 2014 2:24:27 PM UTC-5, Paul T wrote:
>> The Discus 2 is now well over 15 years old - why is there nothing
better
>in Standard Class? Has glider design reached a plateau in terms of
>performance in the Standard Class?
>
>Nobody is buying new Std class gliders, in part because it is a quietly
>shrinking class.
>There is no market incentive for manufacturers to develop a new glider,
>especially when they can put their effort into the popular 18 meter
gliders
>that the wealthy glider buying class seems to want while generating
>susstantially more revenue per sale.
>For racers, this is actaully a good thing because there are plenty of
>D2's,28's LS-8's, etc that can be had reasonably and allow a pilot to be
>competitive.
>One view
>UH
>

[Cookie]

Duckhawk???


Cookie

On Saturday, January 4, 2014 4:22:06 AM UTC-5, Peter F wrote:
> Same is pretty much true in all the "smaller" classes
>
>
>
> 15m class there's not really anything "better" than the V2a or ASW27, both
>
> of which are pretty ancient designs

[son_of_flubber]

On Saturday, January 4, 2014 4:22:06 AM UTC-5, Peter F wrote:
> Same is pretty much true in all the "smaller" classes

But for 13.5 M lightweight:

http://windward-performance.com/sparrowhawk-r/

GP-10 https://groups.google.com/forum/#!topic/rec.aviation.soaring/dMK7spGOnaU

[[email protected]]

On Friday, January 3, 2014 1:24:27 PM UTC-6, Paul T wrote:
> The Discus 2 is now well over 15 years old - why is there nothing better in
>
> Standard Class? Has glider design reached a plateau in terms of performance
>
> in the Standard Class?

Paul, flying an LS8-18, I have of course to take issue with your premise of the "best Standard Class Glider". However, UH is right on all points, manufacturers concentrate on higher revenue classes. Also, the development potential of unflapped 15m wings (and maybe the flapped ones as well) is minuscule and does not warrant a new design. Rolladen Schneider basically took the LS6 fuselage and wings (sans flaps) and optimized those components for a "new" model they called LS8 - and it is still competitive.
ASW-28, Discus 2 and LS8's are very much in demand with prices of $70-$80k and with new 18m ships costing $150k+ I can see why: you get about the same enjoyment and OLC miles for half the price. So yes, Standard Class has peaked and there's not too much wrong with that.
Herb

[Jerzy]

On Saturday, January 4, 2014 4:22:06 AM UTC-5, Peter F wrote:
> Same is pretty much true in all the "smaller" classes
>
>
>
> 15m class there's not really anything "better" than the V2a or ASW27, both
>
> of which are pretty ancient designs
>
>
>
> 18m class, the new kid on the block is the JS1, the V2cx & ASG29 are still
>
> pretty close - JS1 has "Open class" option
>
>
>
> The newest gliders seem to be appearing in open class. But Schempp &
>
> Schleicher has now produced their offerings.
>
>
>
> 2-seat XC class seems stable with the Duo, Arcus & soon ASG32
>
>
>
> Not sure I'd want to be starting a career in glider design right now.
>
>
>
> The only opening I can see is for a competitor for the K21
>
> Relatively low cost, strong, reasonable performance, fly the whole training
>
> curriculum including spinning.
>
> A bit like the fixed wheel DG1000
>
>
>
> PF
>
>
>
>
>
> At 20:16 03 January 2014, wrote:
>
> >On Friday, January 3, 2014 2:24:27 PM UTC-5, Paul T wrote:
>
> >> The Discus 2 is now well over 15 years old - why is there nothing
>
> better
>
> >in Standard Class? Has glider design reached a plateau in terms of
>
> >performance in the Standard Class?
>
> >
>
> >Nobody is buying new Std class gliders, in part because it is a quietly
>
> >shrinking class.
>
> >There is no market incentive for manufacturers to develop a new glider,
>
> >especially when they can put their effort into the popular 18 meter
>
> gliders
>
> >that the wealthy glider buying class seems to want while generating
>
> >susstantially more revenue per sale.
>
> >For racers, this is actaully a good thing because there are plenty of
>
> >D2's,28's LS-8's, etc that can be had reasonably and allow a pilot to be
>
> >competitive.
>
> >One view
>
> >UH
>
"> >
"The only opening I can see is for a competitor for the K21

Relatively low cost, strong, reasonable performance, fly the whole training

curriculum including spinning.

A bit like the fixed wheel DG1000
PF
And SZD 54-2 Perkoz is exactly what you desire
http://www.windpath.ca/index.php?option=com_content&view=article&id=35&Itemid=8
Jerzy

[Paul T[_4_]]

At 15:19 04 January 2014, wrote:
>On Friday, January 3, 2014 1:24:27 PM UTC-6, Paul T wrote:
>> The Discus 2 is now well over 15 years old - why is there nothing
better
>=
>in
>>=20
>> Standard Class? Has glider design reached a plateau in terms of
>performan=
>ce
>>=20
>> in the Standard Class?
>
>Paul, flying an LS8-18, I have of course to take issue with your premise
>of=
> the "best Standard Class Glider". However, UH is right on all points,
>man=
>ufacturers concentrate on higher revenue classes. Also, the development
>po=
>tential of unflapped 15m wings (and maybe the flapped ones as well) is
>minu=
>scule and does not warrant a new design. Rolladen Schneider basically
>took=
> the LS6 fuselage and wings (sans flaps) and optimized those components
>for=
> a "new" model they called LS8 - and it is still competitive.
>ASW-28, Discus 2 and LS8's are very much in demand with prices of
$70-$80k
>=
>and with new 18m ships costing $150k+ I can see why: you get about the
>sam=
>e enjoyment and OLC miles for half the price. So yes, Standard Class has
>p=
>eaked and there's not too much wrong with that.
>Herb

I think nearly everyone conceedes that the Discus 2a is the best performer
in Standard Class - whether is the best standard class glider is another
issue!

I wonder if IGC (and manufacturers?) hadn't 'invented' these new classes
i.e. 18m, 20m two seat, 13.5m we would have seen more radical development
in std and 15m class?

I think someone forgot about the SZD56-2 Diana in 15m class! -as for the
Duckhawk it has yet to prove itself on the international scene.

[son_of_flubber]

On Saturday, January 4, 2014 3:19:15 PM UTC-5, Paul T wrote:
> -as for the
> Duckhawk it has yet to prove itself on the international scene.

Someone should step up, buy one, and win a few international races in it. Or put a promising youngster in it as their proxy.

[Chip Bearden[_2_]]

It's worse/better, even, than UH details. In my admittedly personal experience, there's very little if any difference in performance between the D2/ASW 28/LS 8 and the previous generation ASW 24, a design that goes back more than TWENTY-FIVE years! The caveat, of course, would be "with the right winglets", for which UH has a lot of responsibility (his winglets are on my 24 and many others).

In addition to claimed incrementally higher performance, what the later designs offered were optional 18m wingtips (although I'm not sure how many owners opted for these), more crashworthy cockpits (in the case of the D2 and LS 8; the ASW 24's already outstanding design was the basis for the ASW 27, ASW 28, and ASG 29 fuselages) and perhaps a bit easier, though not necessarily better, thermaling.

But when you look back over the preceding decades, the advances in performance have been minuscule. Is this because the technology ceased to advance, or because of lack of demand, or--in a sort of chicken-and-the-egg fashion--both?

Chip Bearden
ASW 24 "JB"
U.S.A.

[Eric Greenwell[_4_]]

Chip Bearden wrote, On 1/4/2014 10:07 PM:
> In addition to claimed incrementally higher performance, what the
> later designs offered were optional 18m wingtips (although I'm not
> sure how many owners opted for these), more crashworthy cockpits (in
> the case of the D2 and LS 8; the ASW 24's already outstanding design
> was the basis for the ASW 27, ASW 28, and ASG 29 fuselages) and
> perhaps a bit easier, though not necessarily better, thermaling.

The ASH 26 also used the ASW 24 cockpit design concepts, as have all
succeeding Schleicher gliders (with improvements along the way, of
course). I don't think the ASH 25 incorporated the 24's concepts, as
it's design seems to pre-date the 24, and it flew first, about a year
earlier.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[[email protected]]

I'm not so sure there has been all that much recent aerodynamic improvements in glider design. Nothing as drastic as the transition between "classic" and laminar profiles.

Every new generation of laminar profiles has marginally improved the performance, but we seem to have reached a plateau where Boermans, the profile guru from Delft University, is looking towards boundary layer aspiration for a new leap forward. If successful, this will be costly.

It is much easier to improve the performance by 1) increasing the wingspan (within limits imposed by structural problems and maneuverability); 2) increasing the aspect ratio of the wing (within limits imposed by Reynolds number effects within a fixed wingspan).

The new "small open class" seems to correspond to an optimal compromise for the current generation of laminar profiles.

15 meter sailplanes seem to fall on the wrong side of the optimum. They are also less apt to be equipped with an engine due to the impact on their minimum wing loading. Their only reason of existence now seems to be their lower price. But you never know what the future will bring…

[[email protected]]

On Tuesday, January 7, 2014 3:22:15 PM UTC-5, wrote:
> I'm not so sure there has been all that much recent aerodynamic improvements in glider design. Nothing as drastic as the transition between "classic" and laminar profiles. Every new generation of laminar profiles has marginally improved the performance, but we seem to have reached a plateau where Boermans, the profile guru from Delft University, is looking towards boundary layer aspiration for a new leap forward. If successful, this will be costly. It is much easier to improve the performance by 1) increasing the wingspan (within limits imposed by structural problems and maneuverability); 2) increasing the aspect ratio of the wing (within limits imposed by Reynolds number effects within a fixed wingspan). The new "small open class" seems to correspond to an optimal compromise for the current generation of laminar profiles. 15 meter sailplanes seem to fall on the wrong side of the optimum. They are also less apt to be equipped with an engine due to the impact on their minimum wing loading. Their only reason of existence now seems to be their lower price. But you never know what the future will bring…

That would depend on the definition of "optimum".
If the definition of "optimum" were to include reasonable weight single piece wings, glide angles in the high 40's, and wonderful handling, I'd say that there are many gliders in the fleet that would meet the definition and justify their "existance".
If the definition includes ability to add an engine and retain a reasonable minimum wing loading, then it would seem to move toward 18 meters with the associated increase in cost and complexity.
Either option uses airfoils that get 95% laminar flow on the bottom and somewhat beyond 60% on the top.
And price is a factor for some buyers.
FWIW
UH