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World Contest - 15m class



 
 
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  #11  
Old November 21st 16, 01:16 AM posted to rec.aviation.soaring
Casey[_2_]
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Default World Contest - 15m class

On Sunday, November 20, 2016 at 10:24:54 AM UTC-5, Jonathan St. Cloud wrote:
The new Jonker 13.5/15 meter glider.

On Sunday, November 20, 2016 at 1:15:08 AM UTC-8, Iain Baker wrote:
At 05:19 20 November 2016, Jock Proudfoot wrote:
The Jonker brothers are entered in the 15m class
What model glider will they fly ?


What....13.5/15? Must be stealthy, but why keep that under wraps when most start leaking new models to get some to hold off on a competitor purchase. Do tell more?
  #12  
Old November 21st 16, 08:26 PM posted to rec.aviation.soaring
Iain Baker
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Default World Contest - 15m class

At 00:16 21 November 2016, Casey wrote:
On Sunday, November 20, 2016 at 10:24:54 AM UTC-5, Jonathan St.

Cloud
wrote:
The new Jonker 13.5/15 meter glider.

At 05:19 20 November 2016, Jock Proudfoot wrote:
The Jonker brothers are entered in the 15m class
What model glider will they fly ?


What....13.5/15? Must be stealthy, but why keep that under wraps

when most
start leaking new models to get some to hold off on a competitor

purchase.
Do tell more?


In 7th FAI SGP World Final - Race 4 video on YouTube 1:52:15 onwards
listen to Uys Jonker reveal some information...first public mention of
the JS3.

And in 7th FAI SGP World Final – Race 6 video on YouTube at 1:16:00
the commentators Shaun Lapworth and Brian Spreckley mention a
Jonker Sailplanes factory tour looking at the new JS3, a 15/18m
glider….and that the 18m version will be better than today’s JS1-18m.


  #13  
Old November 22nd 16, 05:17 AM posted to rec.aviation.soaring
Sean[_2_]
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Default World Contest - 15m class

Uys made an excellent 45 minute presentation on the JS2 (or 3?) in Nephi last summer. He talked about their innovative CFD philosophy and robust computational processing power. As with many industries, highly iterative "trail and error" testing has proven to be very successful vs the more traditional iteration processes used by the established sailplane manufacturing firms.

For example, the V3 has not resulted in a new fuselage design. It's basically the same fuselage as the V2. Only very minor changes. Same control system, etc. But Yonkers believes any major performance improvements MUST include total design innovation. The fuselage is as critical as the wing. They are symbiotic, not individual parts. They both require highly integrated design attention in order to deliver maximum performance gains. As improvements in glider design are harder and harder to come by, a complete design philosophy including total fuselage innovation (such as shaping, wing position [high, mid or low], structure, total wetted area minimization, boom shape, tail improvements, etc) is required to realize significant performance (and safety) improvement. With traditional, less iterative processes (not highly iterative CFD modeling), the other companies cannot afford the testing time required to prove benefits in total design enhancements. So, SH focused on the wing primarily for the V3. They left performance on the table by not putting the same effort into the fuselage and the integration between the two elements. I found this argument to be fairly interesting.

It was a very interesting presentation Uys gave us in Nephi. Unfortunately, we will likely only see the 15 meter version JS2 in Australia. We will have to wait a bit to see the JS2, V3 and 29 do battle.

I think the JS2 is going to be impressive. Obviously they intend to beat (not match) the current 15/18 gliders, by a compelling margin. The JS2 will be the first completely new 18 meter design since the JS1 and JS1c Evo. The V2 and 29 came years earlier. I think the JS1 is equal (or slightly better in weak) to the 29. I think the JS2 will certainly be better than the JS1. And I honestly think the V3 was intended to be "competitive" with the JS1 and 29. I have my doubts that the V3 will be a significantly better performer in any condition. I believe it may struggle in weak, rough weather. We will see in a month or so...

So, I'm sitting on my hands for now. Until the 29 is uncompetitive, why change? The 29 is a highly proven glider and still the king to this moment.
  #14  
Old November 22nd 16, 01:59 PM posted to rec.aviation.soaring
krasw
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Default World Contest - 15m class

On Tuesday, 22 November 2016 06:17:23 UTC+2, Sean wrote:
For example, the V3 has not resulted in a new fuselage design. It's basically the same fuselage as the V2. Only very minor changes. Same control system, etc. But Yonkers believes any major performance improvements MUST include total design innovation. The fuselage is as critical as the wing.


Does this mean that Jonkers is actually going to make their first original fuselage design?
  #15  
Old November 22nd 16, 08:17 PM posted to rec.aviation.soaring
Sean[_2_]
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Default World Contest - 15m class

I guess so. Did they copy something?
  #16  
Old November 22nd 16, 08:42 PM posted to rec.aviation.soaring
krasw
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Default 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?
  #17  
Old November 23rd 16, 04:09 PM posted to rec.aviation.soaring
[email protected]
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Default World Contest - 15m class

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"
  #18  
Old November 23rd 16, 05:10 PM posted to rec.aviation.soaring
Tango Eight
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Default World Contest - 15m class

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
  #19  
Old November 23rd 16, 05:16 PM posted to rec.aviation.soaring
Sean[_2_]
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Default World Contest - 15m class

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...



  #20  
Old November 23rd 16, 06:29 PM posted to rec.aviation.soaring
krasw
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Posts: 668
Default World Contest - 15m class

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?
 




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