Moderators: richierich, ua900, PanAm_DC10, hOMSaR
patrickjp93 wrote:We know it's coming, just a matter of when, so between the Trent Ultrafan's big efficiency improvements (7-10% over the XWB seems likely) and Airbus' improvements to the frame (wing twist, new laminar coatings/designs from Project BLADE, folding wingtips, etc.), what do we think the A350 NEO specs will be?
With a 10% range improvement, the A350 900 and 1000 base models have the same and higher range than the 777-8. Not quite the 18,000km of the -900ULR, but that's before any pax or cargo restrictions. The only routes much longer than 17,200km are Aukland to London, Singapore to Chicago, and Perth to NYC, and of those, only Aukland-London has been seriously floated.
So, would this not, essentially, remove the need to have an A350 NEO ULR?
And as a side question, with the delayed EIS for the 777-8, should Boeing even bother with it at this point if they don't win the Project Sunrise bid?
Its wing sweep is around 20° for a Mach 0.75 cruise instead of 30° for Mach 0.82-0.84, laminar flow is expected along 50% of chord length instead of just aft of the leading edge, halving the wing friction drag, reducing the overall aircraft drag by 8% and saving up to 5% in fuel on an 800nm (1,480km) sector.[1]
...
The aerodynamic benefits could be sustained at Mach 0.78 up from M0.75 and next-generation single-aisles could use from the late 2020s.
Revelation wrote:First, I think it's a question of time to market. QF has put its flag in the ground on PER-LHR and wants to be the pioneer on SYD-LHR. They do not want to wait till A350neo with UltraFan is ready for market.
Second, I would not pencil in BLADE improvements. As https://en.wikipedia.org/wiki/Breakthro ... _in_Europe says:Its wing sweep is around 20° for a Mach 0.75 cruise instead of 30° for Mach 0.82-0.84, laminar flow is expected along 50% of chord length instead of just aft of the leading edge, halving the wing friction drag, reducing the overall aircraft drag by 8% and saving up to 5% in fuel on an 800nm (1,480km) sector.[1]
...
The aerodynamic benefits could be sustained at Mach 0.78 up from M0.75 and next-generation single-aisles could use from the late 2020s.
The A350's wing has a 31.9° sweep angle for a Mach 0.85 cruise speed ( ref: https://en.wikipedia.org/wiki/Airbus_A350_XWB ).
The BLADE results are very good, but really only meaningful for a single aisle where cruise speed is not commercially significant.
Also BLADE only works when one holds extremely high manufacturing tolerances, which adds a lot of cost to build and maintain so you'd only use it when it paid for itself.
A350neo would need an all-new wing with redesign of the wingbox for different sweep angle and accept a slower cruise speed to benefit from BLADE.
I don't think this is the approach Airbus will take for A350neo.
And I think QF is happy to take the bird in hand rather than the two in the bush.
patrickjp93 wrote:Thanks for the info. That said, there'll be derivative IP coming out of BLADE. We know mach 0.78 is much more efficient than 0.85, just as mach 5+ is more efficient than 4.9 and down for supersonic flight. But no one would want to SLOW DOWN a 20+ hour flight to a 22 hour flight.
Revelation wrote:I agree. We can have gotten many generations of improvements from engines but researchers say that we're hitting fundamental limits and we will need to look elsewhere for gains, with laminar flow being one of the obvious areas to look at. The problem is even when we can make it work we sacrifice speed and increase cost to build and maintain, yet various clean air initiatives will make it so it has to be put into production. I think the quoted late 2020s narrow body airliner is a likely target.
Revelation wrote:Also BLADE only works when one holds extremely high manufacturing tolerances, which adds a lot of cost to build and maintain so you'd only use it when it paid for itself.
patrickjp93 wrote:Again, there's just no practical use for a plane with 19,800km of range, which would be an exact 10% improvement for the A350-900ULR,
DocLightning wrote:Revelation wrote:Also BLADE only works when one holds extremely high manufacturing tolerances, which adds a lot of cost to build and maintain so you'd only use it when it paid for itself.
And BLADE stops working when a bug gets smushed on the leading edge, at least in that small section. That's something that they're going to have to figure out before EIS, because bugs and dirt are part of real-world operations.
DocLightning wrote:And BLADE stops working when a bug gets smushed on the leading edge, at least in that small section. That's something that they're going to have to figure out before EIS, because bugs and dirt are part of real-world operations.
.
WIederling wrote:Results from BLADE seem to show that requirements can be slightly relaxed
and resilience to disturbances is better than expected.
Armadillo1 wrote:http://www.aeromorning.com/en/asco-completes-the-delivery-of-innovative-high-lift-devices-to-airbus/
Krueger flaps has been delivered in june 2017.
as i can see in news "test will continue until 2019" which i interpreting as "in 2018"
will be interesting to find more info about this
Armadillo1 wrote:yep, we looking at the same google at the same time.
interesting those krueger flaps very different from 747 and really looks like shields
WIederling wrote:Armadillo1 wrote:yep, we looking at the same google at the same time.
interesting those krueger flaps very different from 747 and really looks like shields
Basic concept of a Krüger Flap is folding a piece of the wing underside to extend beyond
the nose profile. ( where slats are a piece of the nose moved out/down and
drop nose devices rotate a piece of the nose profile down.)
Doesn't the 747 have a multipart articulated Krüger flap design?
WIederling wrote:Well it is a Krueger articulated (sealed? no ) slat then?
though my understanding of Krueger would require it to simply hinge near the lower tip of the nose.
( what made the original design from Krüger very attractive.)
This flap here shows complex articulation .
Proper low disturbance sealing of the retracted flap can't be easy.
Armadillo1 wrote:english not my language so i have no idea why Krueger slats named flaps.
patrickjp93 wrote:So, would this not, essentially, remove the need to have an A350 NEO ULR?
patrickjp93 wrote:And as a side question, with the delayed EIS for the 777-8, should Boeing even bother with it at this point if they don't win the Project Sunrise bid?
RJMAZ wrote:patrickjp93 wrote:So, would this not, essentially, remove the need to have an A350 NEO ULR?
The A350 family is already at the edge of the widebody sweet spot. The A330-300 and 777-300ER were the two big sellers that give an idea of the sweet spot. The A350 is on the upper edge of the sweet spot for size. The range of the A350 is pushing beyond the sweet spot and is close to the niche aircraft like the A340-500 and 777LR. Both of these did not sell.
Once the A350NEO comes it will have too much range and a lighter frame of similar cabin area can offer more efficiency. The 787-10 NEO will be the big seller in the future.
patrickjp93 wrote:And as a side question, with the delayed EIS for the 777-8, should Boeing even bother with it at this point if they don't win the Project Sunrise bid?
Boeing definitely shouldn't bother with the 777-8 if it does not get selected for Project Sunrise.
I actually think the VLA market is shrinking faster than people think. The A380 retirement plans are faster than we would expect which shows the demand must extremely high for medium sized widebodies. Pushing investment into the 787 might prove the smart option and reap rewards in 10 years time. A 787-8ER and 787-8 freighter would be the safe option right now.
The second problem is the big winged 777X is built for long range cruise which makes it a poor freighter with next to no improvement over the current 777F. The argument that the 777-8 should be built so that it can become the future freighter if a poor argument.
Boeing got one thing right with the 787 it was sized perfectly for decades to come.