Opus99 wrote:jagraham wrote:lightsaber wrote:How GE could acheive 10% in ten years:
1. 3.5: 1 GTF, about 6.5% fuel burn reduction
2. Higher match # high pressure compressor (needs better bearings and seals), about 1% fuel burn reduction
3. Fan improvements, about 0.2%(yes, just a fraction of a percent)
4. CMC inlet guide vanes to high turbine: 2.5% (s/b within 5 years, if not sooner)
5. CMC turbine stators, perhaps 0.5%
6. CMC combustor liners, perhaps 0.5%
7. Now what is really in question for within ten years, is CMC 2nd stage high turbine blades (about 2.5%), but due to the stresses, iffy. I do not consider 1st stage turbine blades possible within ten years, but that is just my opinion.
8. Improved compressor variable bleet (0.25% or so)
9. Improved variable turbine cooling (0.35% or so)
They also need to add to the 787 the GE9x technologies (already developed):
10. Variable turbine cooling, 2.7% or so
11. Improved cooling loops 0.75% or so
12. CMC coated combustor liner 0.2%
13. Fan blade tech (needs a new design to change bypass ratio) 0.5%
The could also do conter-rotation,but GE has chosen a different tech path and this might be a bridge too far in terms of bearing and seal speeds.
What about just putting GE9X on the 787? The GE9X is supposed to already be 10% better than the GEnx - although at about a 5000 lb per engine penalty . . .
10% better than the GE90*
A blend of evolutionary and revolutionary designs will enable the GE9X to be the most fuel-efficient jet engine GE has ever produced on a per-pounds-of-thrust basis. It’s designed to deliver a 10% improved aircraft fuel burn versus the GE90-115B-powered 777-300ER and a 5% improved specific fuel consumption versus any twin-aisle engine available, plus achieve an approximate 10:1 bypass ratio, a 60:1 overall pressure ratio and margin to Stage 5 noise limits.
https://www.geaviation.com/commercial/e ... aft-engine
While GE won't mention competitors in their brochures, we all know that "any twin-aisle engine available" means the Trent XWB . . . So GE is advertising 5% better than Trent XWB