World Contest - 15m class

On Tuesday, 22 November 2016 21:17:50 UTC+2, Sean wrote:
I guess so. Did they copy something?

If I remember the story right, Schleicher provided an ASH26 fuselage for S-African Tech. University for research purposes. Few years later it was copied into JS1 fuselage. Others may fill in if I missed some facts, it's been 10 years since I heard the story from Heide (who was not very happy about it). Are you saying you haven't noticed the obvious similarity between '26 and JS?

On Tuesday, November 22, 2016 at 12:42:55 PM UTC-7, krasw wrote:

If I remember the story right, Schleicher provided an ASH26 fuselage for S-African Tech. University for research purposes. Few years later it was copied into JS1 fuselage. Others may fill in if I missed some facts, it's been 10 years since I heard the story from Heide (who was not very happy about it). Are you saying you haven't noticed the obvious similarity between '26 and JS?

IIRC, The story used to be on the JS website. They did start with an AS fuse (Purchased with the companys blessing) with the intention of making a new wing. It was determined that too many changes would need to be made for this to be practical so the idea was scraped and the fuse was later used for the repair of an AS glider. Much of the presentation at Nephi centered around the development of the fuse and the wing junction.
I will say that form follows function and when you look close there are similarities among many modern gliders.
Just filling in "Facts"

On Wednesday, November 23, 2016 at 10:09:27 AM UTC-5, wrote:
On Tuesday, November 22, 2016 at 12:42:55 PM UTC-7, krasw wrote:

If I remember the story right, Schleicher provided an ASH26 fuselage for S-African Tech. University for research purposes. Few years later it was copied into JS1 fuselage. Others may fill in if I missed some facts, it's been 10 years since I heard the story from Heide (who was not very happy about it). Are you saying you haven't noticed the obvious similarity between '26 and JS?

IIRC, The story used to be on the JS website. They did start with an AS fuse (Purchased with the companys blessing) with the intention of making a new wing. It was determined that too many changes would need to be made for this to be practical so the idea was scraped and the fuse was later used for the repair of an AS glider. Much of the presentation at Nephi centered around the development of the fuse and the wing junction.
I will say that form follows function and when you look close there are similarities among many modern gliders.
Just filling in "Facts"

http://www.postfrontal.com/PDF/prove_alianti/JS1.pdf

Some people might be forgiven for seeing things a bit differently.

-Evan

I had not really noticed the 26 being very similar to the JS1... I'm looking now and the fin and nose. It does not look the same to me. Maybe a bit. The mid position of the wing looks similar. If true, I give them a pass as they were just starting out as a brand new company. It actually makes sense from an economic perspective, but of course copying an existing fuselage is a big compromise on achieving maximum possible performance. The 26 is a beautiful glider so at least they have good taste.

My opinion (years of CAE experience with racing sailboat design, from keel bulbs and fins to rudders and hulls and especially sails) is that Uys is correct. By not including the fuselage in any "new" design, much potential performance gain is naturally "left on the table." This is of course not rocket science. This is a matter of economics.

What is the minimum required performance gain required to get the flock to "fly over the the new pond?" Obviously, the new wing on the V3 was "enough" to get many SH owners "into the air!" But will that prove to be a mistake?

To have the best chance at significant performance improvement, the whole sailplane and all of its critical aerodynamic interrelationships must be iterated (extensively and carefully) together. Again, this is not rocket science. It's a simple matter of potential opportunity for aerodynamic improvement. 50% of the glider or 100%?

I often helped racing sailboat owners redesign their rudder or the keel fin in the never ending struggling to remain competitive (early 90's). But this conservative approach was never really competitive with the totally new designs (several each season) in a period of rapid advancement in sailing technology. This effort to "stem the tide" was almost always futile! Most serious owners could only procure new boat every 3-5 years. The design process alone took over a year, then a year or two to build, and so on. Sailplane design is on a much slower pace that sailing is/was. Significant, new sailplane designs seem to come along every ten years or so. That might slow as the sport slows. That makes each sailplane purchase decision critical, especially if you cannot afford a new glider every season. The million dollar question is: "How long will your new glider be the competitive?"

1 year, 3 years, 10 years? 6 months? Never?

So, the ASG29 was not truly new when it was released ten years ago. My registration actually says ASG 27-18 - SN4! But it used airfoils from very proven gliders (part 27 airfoil and part new airfoil, I believe) but it has also been the clear king of 18m and very competitive in 15m for years. The 29 is the baseline of all 18m gliders to this day.

At about the same time (?) the V2 came along. I'm not sure of its design background but it has also not been competitive with the ASG29, especially in strong conditions. Even with the "X" version. I don't believe th 29 has ever been changed in the slightest.

Then came the JS1, three or four years later. It seems to basically match the ASG29 and truly challenges its performance in weaker conditions. Later yet came the JS1 EVO improvement and this might have tipped the scales slightly in the JS1s favor in weak conditions.

Today, SH designed what is essentially a "new wing" for the V2 and aptly calls it V3! Ta da! The wing is much thinner than the V2s and is intended to run "extremely well" compared to the V2 based on contest flying behavior research. But will it climb effectively in weaker conditions? The same fuselage as the V2 appears to have been used for the V3. This calls into question how large the improvement "can be" as the V2 was already a step behind the 29 and JS1 in most conditions. The V2 fuselage is, obviously, VERY FAT (lots of wetted area) and therefore so is the V3 fuselage. Results of the V3 design strategy are still largely unknown.

Finally the new JS2 appears on the scene. This is (apparently) the first "ground up" brand new sailplane design that any of us have seen in a long time. It has less (perhaps none) of the traditional compromises. It appears to be a totally new sailplane design with the stated design goal of significant performance improvement over its own already leading product. A completely redesigned fuselage, new wing, new tail, new cockpit, etc. Everything was intensely studied and iterated via their rapid CFD design process. Their design process is proving to be a tremendous business advantage. It offers JS maybe a 10-20x improvement in iteration speed and therefore refinement opportunity. Time is truly money. They are able to "keep the pressure on!"

JS had the advantage of already having one of the top two 18m racing sailplanes (essentially tied with the 29). Their design strategy and process, in my eyes, appears to be highly credible. So credible that the German sailplane manufacturers have recently begged their government for money to catch up and compete in terms of CFD computing power. Great, but they are now years behind JS is experience in this kind of iterative design process. Their time to market is obviously slower. We do not know if the V3 will actually be a match for the JS1 EVO yet (I believe that 'match or slightly exceed' the current benchmark was the design goal for the V3).

Exciting times as some very big, strategic cards are about to be put down down on the table...

On Wednesday, 23 November 2016 18:16:58 UTC+2, Sean wrote:
The 26 is a beautiful glider so at least they have good taste.

Agreed. No matter what the story is (there is always two sides of coin), AS did not willingly donate the aerodynamic shape of '26 fuselage to competing manufacturer.


So, the ASG29 was not truly new when it was released ten years ago. My registration actually says ASG 27-18

That is just paperwork. Factory has to pay annually to EASA for every type-certificate data sheet it owns. Schleicher has over 20 of these, Airbus only four. So they decided to use '27 data sheet for '29. Sure it inherits a lot from '27, but it is still different animal. I think it was 29 and 18m tips that revealed the full potential of Waibel's original design.


Today, SH designed what is essentially a "new wing" for the V2 and aptly calls it V3! Ta da! The wing is much thinner than the V2s and is intended to run "extremely well" compared to the V2 based on contest flying behavior research. But will it climb effectively in weaker conditions? The same fuselage as the V2 appears to have been used for the V3. This calls into question how large the improvement "can be" as the V2 was already a step behind the 29 and JS1 in most conditions. The V2 fuselage is, obviously, VERY FAT (lots of wetted area) and therefore so is the V3 fuselage. Results of the V3 design strategy are still largely unknown.


Using same fuselage for different types is quite normal. LS1-f/LS6/LS7/LS8/LS10, ASW24/27/28/ASG29, Ventus a/2a/3a/Discus a/2a, ASH26/JS1 etc. I think the Ventus 3 has flown only with a-cockpit, which has lowest wetted area of anything because it is so small. You are confusing Schempp's big b/c-model fuselage with small a-model. Your speculation about V3 wing is based on what exactly?

On Wednesday, November 23, 2016 at 8:29:04 PM UTC+3, krasw wrote:
On Wednesday, 23 November 2016 18:16:58 UTC+2, Sean wrote:
The 26 is a beautiful glider so at least they have good taste.

Agreed. No matter what the story is (there is always two sides of coin), AS did not willingly donate the aerodynamic shape of '26 fuselage to competing manufacturer.


So, the ASG29 was not truly new when it was released ten years ago. My registration actually says ASG 27-18

That is just paperwork. Factory has to pay annually to EASA for every type-certificate data sheet it owns. Schleicher has over 20 of these, Airbus only four. So they decided to use '27 data sheet for '29. Sure it inherits a lot from '27, but it is still different animal. I think it was 29 and 18m tips that revealed the full potential of Waibel's original design.


Today, SH designed what is essentially a "new wing" for the V2 and aptly calls it V3! Ta da! The wing is much thinner than the V2s and is intended to run "extremely well" compared to the V2 based on contest flying behavior research. But will it climb effectively in weaker conditions? The same fuselage as the V2 appears to have been used for the V3. This calls into question how large the improvement "can be" as the V2 was already a step behind the 29 and JS1 in most conditions. The V2 fuselage is, obviously, VERY FAT (lots of wetted area) and therefore so is the V3 fuselage. Results of the V3 design strategy are still largely unknown.


Using same fuselage for different types is quite normal. LS1-f/LS6/LS7/LS8/LS10, ASW24/27/28/ASG29, Ventus a/2a/3a/Discus a/2a, ASH26/JS1 etc. I think the Ventus 3 has flown only with a-cockpit, which has lowest wetted area of anything because it is so small. You are confusing Schempp's big b/c-model fuselage with small a-model. Your speculation about V3 wing is based on what exactly?

The same canopy fits a mid 1970s Janus and a modern Duo Discus!

The Ventus 3 is not represented yet on the Schempp Hirth website...

https://www.schempp-hirth.com/en.html

Interesting.

The general design brief for the V3 (wing only) is, therefore, not well marketed (or even formally published) although I suspect that a purchase of the SH presentation from the recent SSA convention from 'Wings and Wheels' would discuss the V3 design brief in great detail. Take a look at DVD #14 he http://wingsandwheels.com/pilot-supp...tion-dvd..html

https://www.schempp-hirth.com/en.html

It essentially goes like this: "by studying flight traces (glide/climb ratios, speeds, climb rates, etc) from actual competition flights, they believe the current airfoils are not optimized (essentially to thick, too high drag) so the adopted a new airfoil (thinner essentially) optimized for better high speed glide performance and (likely) slightly less performance in climb. In other words they cite that competition gliders are flying faster than optimum (for their current V2 airfoils) and climbing less that predicted.. So they have built a new wing optimized for the speeds and climb percentages that are actually being flown in real competition."

This design strategy is well known among the SH community and is the basis for the arguement that the V3 will have exceptional performance in competition. It has also resulted in a large book of pre-orders.

We shall see the results of the new wing shortly.

Sean

Interesting that the Quintus is listed on their web site, even after they updated it last year. The Quintus is not in production and since SH never went through any of the certification process they cannot build any more of the quintus, too bad the world needs another true open class gliders with long wings.

On Thursday, November 24, 2016 at 7:55:24 AM UTC-8, Sean wrote:
The Ventus 3 is not represented yet on the Schempp Hirth website...

https://www.schempp-hirth.com/en.html

Interesting.

On Thursday, November 24, 2016 at 8:55:24 AM UTC-7, Sean wrote:
The Ventus 3 is not represented yet on the Schempp Hirth website...

https://www.schempp-hirth.com/en.html

Interesting.

The general design brief for the V3 (wing only) is, therefore, not well marketed (or even formally published) although I suspect that a purchase of the SH presentation from the recent SSA convention from 'Wings and Wheels' would discuss the V3 design brief in great detail. Take a look at DVD #14 he http://wingsandwheels.com/pilot-supp...ntion-dvd.html

https://www.schempp-hirth.com/en.html

It essentially goes like this: "by studying flight traces (glide/climb ratios, speeds, climb rates, etc) from actual competition flights, they believe the current airfoils are not optimized (essentially to thick, too high drag) so the adopted a new airfoil (thinner essentially) optimized for better high speed glide performance and (likely) slightly less performance in climb. In other words they cite that competition gliders are flying faster than optimum (for their current V2 airfoils) and climbing less that predicted. So they have built a new wing optimized for the speeds and climb percentages that are actually being flown in real competition."

This design strategy is well known among the SH community and is the basis for the arguement that the V3 will have exceptional performance in competition. It has also resulted in a large book of pre-orders.

We shall see the results of the new wing shortly.

Sean

Well, the V3 has already been raced. UK 18 Meter Nationals Aug 20 thru 26th..

Steve Jones is one of the best.
I cut this link(may not work) but full results are here.
http://www.soaringspot.com/en_gb/tibenham-18m-.

1 565 Brian Birlison ASG 29E 1,918
2 80 Andy Davis JS1c Evo 1,915
3 E1 Russell Cheetham JS1c Evo 1,822
4 E11 Stephen Ell ASG 29E 1,812
5 10 Gary Stingemore ASG 29E 1,806
6 N1 Peter Harvey JS1c 1,763
7 601 Tim Jenkinson ASG29E 1,752
8 9 Rory Ellis ASG 29E 1,695
9 3V Steve Jones Ventus 3 1,681
10 XS Richard Browne JS1c 1,629

Bet. Tom #711.

Interesting Tom. Schempp Hirth would have been all over these results (social media, etc) if they were favorable. News of the V3 has been fairly difficult to find. They probably still have a bit of tuning left to do. Let's hope, for their sake, the glider ends up performing better than that.