|Quoting rbavfan (Reply 60):|
Change of spec on an engine does not always mean increased weight. The RB211-524 when to G/H-T improving hot/high performance while lowering weight with the trent 700 core by around 500 lb. I do believe.
are the variants of the RB211-524G2-19
engines and feature the RB211-Trent 700
´s 04 high pressure Module - technology developed on the Trent 700
engine family in 1997, but also comprising some other modifications to provide improved engine performance and reliability. On the RB211-524G/H-T
engines, the HP
turbine system is designed to operate at Trent 700
´s temperatures that are significantly higher than at the previous models of engines. Engine models with a suffix ´-T
´ in their name have 87 kg (192 lbs) lower masses
than the previous models of the engines…
|Quoting rbavfan (Reply 61):|
The RB211started out at 42000 lb. st. with the -22B and ended with 60600 lb. st 524G/H-T.
Both with the same 84.8" fan size & 119.4" original & some 524 models, the rest at 122.3"
18600 lb. difference in thrust with improvements.
Not exactly. Those engines do not have the same fan´s diameter…
, RB211-524B2 and RB211-524C2 ….......... 84,8 in. - 215,4 cm fan diameter
RB211-524B4, RB211-524D4 and RB211-524D4-B …… 85,8 in. - 217,9 cm fan diameter
RB211-524G, RB211-524H ………………………………. 86,3 in. - 219,2 cm fan diameter
…………...................... 86,3 in. - 219,2 cm fan diameter
Regardless of the fact that all Rolls-Royce RB211-524
engines share the same architecture, F-7IPC-6HPC ^ 1HPT-1IPT-3LPT, it is obvious that the higher required thrusts - T
[N] and the propulsive efficiency - ŋ
[P] of the engines were obtained through the increased fan´s mass flow - m
I believe that most people do not understand to what were those figures, and in a vague context mentioned: ´& 119.4" original & some 524 models, the rest at 122.3"
´, related to. Those are the incorrect data that Wikipedia states as the length of the mentioned engines. The certificated length of those 524X-T
engines, measured from the front case flange to the rear of INA, is 187,35 in. - 475,9 cm.
For the RB211-524B2
engines, it is 180,4 “ - 458,2 cm, for the RB211-524B4
it is 189,2 “ - 480,5 cm, and for RB211-524D4
engines, this value is 189,8 in. - 482,1 cm, measured from the front of the nose to the end of the jet pipe nozzle.
|Quoting rbavfan (Reply 61):|
Trent 1000 started out at 64100 lb. st. has been derated to 53200 & 58000 lb. st and increased to 78000 lb. st.
Based on initial (64100) and largest (78000) models what makes you think they cannot get the 82700 out of it.
To my knowledge, there are no
. Trent 1000
engines rated or derated at ˙53200 & 58000 lb. st
´. Trent 1000
engine with the lowest rated thrust is Trent 1000-E
, rated at 265,3 kN - 59.631 lb s.t. Also there is no ´(64100 lb. st.)
´ engine. The closest to this value is Trent 1000-H
engine, rated at 284,2 kN - 63.900 lb s.t. The engines rated at the highest thrusts are Trent 1000-J2
and Trent 1000-K2
, both at 347,5 kN - 78.129 lb s.t.
With the respect to the required efficiency and competitiveness of the now-day engines, they are, from the beginning, designed with a small power reserve and work with the very high operating parameters (temperatures, pressures, speeds of rotations, flow speeds...) at their upper calculated limits of the Brayton thermodynamic cycle (thermodynamic cycle that describes the workings of a constant pressure heat engine). It means that the recently constructed engines have smaller, thermally and mechanically more loaded engine´s core and larger fan´s diameter than the engines with the comparable thrust in the (recent) history, including those
The development of the material technology, to a large degree, condition the efficiency of the construction of the modern turbofan engine, and searching for more power and thrust out of the existing or completely new engine´s constructions
, implies the existence of the higher thermal and mechanical stresses of the engine´s construction, and all because of the increasing of their operating parameters (FPR, CPR
, OPR, TIT, flow speeds, rotational speeds…). In the same way as the increased mechanical stresses may affect the fractures and tearing-offs of the materials, the increased long-term temperature stresses could easily cause a change in the structure of the materials leading to their disintegration. Besides, to have a thermally efficient engine does not mean that it is, in the same time, a propulsive efficient engine, just for every purpose.
The fact is that the Emirates
are looking for the increased thrusts for their eventual Boeing 787-10
aircrafts, and all because of the specific climatic conditions at their largest airport. Although it was said that EK
´s Boeing 787-10
s are going to be powered by the
. Trent 1000 -TEN
engines, I would not be surprised at all if the EK
would, once again, change their mind(s) and try to find the solution on the other side, with the General Electric
. The indisputable fact is that the both engines,
. Trent 1000
, certified for the Boeing 787-9
aircraft, are already at their upper limit, but still in the anticipated working area where you can expect them to be highly reliable and safe in their exploitation. It is difficult to speculate how much more thrust could be extracted out of those GEnx-1B
and Trent 1000
engines, but the value of 84x10e3 lb, and that was mentioned, seems to be pretty high for both of those engines, especially if the same expected time of the reliable service and maintenance intervals would be required.
Those recently certified and more powerful General Electric
, rated at 345,2 kN - 77.604 lb s.t. and
, rated at 357,6 kN - 80.392 lb s.t., have not been installed yet, not to my knowledge, on any of the Boeing 787-9
aircrafts delivered to the customers. There are several possible reasons for that, and one of them is that the higher thrust ratings and increased engine´s structural load capabilities would require a somewhat redesigned engine´s nacelles…
On the other side, some of the Boeing 787-9 Dreamliner
s are already powered by the Trent 1000-J2
and Trent 1000-K2
engines (Package C), rated at 347,5 kN - 78.129 lb s.t., while those Boeing 787-9
s, powered by the GEnx-1B
engines, use -1B74/75
version, certified at 340,7 kN - 76.592 lb s.t. It will be very interesting to see on which thrust ratings the new Trent 1000-TEN
engine will be certified…
There is no doubt that the development of those two engines will remain very strong. Trent 1000-TEN
engine is, in a much greater extent, a derivative of a great Trent XWB
engine than the evolution of the existing Trent 1000
, and that speaks enough how much dedicated Rolls-Royce
remains to the Boeing 787 Dreamliner
aircraft and how well prepared they will meet the new Boeing 787-10
. On the other side, General Electric
, in the order to achieve even higher engine´s thrusts, is ready to increase the mass-flow through its GEnx-1B
engine, searching for, not only the higher thrusts, but the increased propulsive efficiency of the engine. Will it be enough to implement in the design all the modern technology aimed for the future GE9X
engine and the technology applied on the already existing LEAP
engine, especially the utilization of the new CMC material in the engine´s hot section (already widely tested on the GEnx-1B
engine), making that way the engine thermally more efficient or the increased fan diameter, redesigned core´s geometry and the architecture will be unavoidable, remains to be seen. Given what have been said in the recent days, I can´t see
. going so far with the development of its GEnx-1B
Since the Boeing
has recently expressed its unreadiness and unwillingness to adjusts Boeing 787-10
to the Emirates
´s needs excessively, and aircraft itself was not designed for the MTOW (557.000 lb - 252.657 kg, according to Boeing´s ´Airport Compatibility Brochure - 787-10 Dreamliner´) higher than the one of the Boeing 787-9
, I wonder how realistic, at all, is it to expect Boeing 787-10
with the engines rated at the thrusts higher than the 80 klb s.t. - 356 kN, if and so much...
As I have already said, a few days ago, in the 787 Production/Delivery thread: no matter what, one thing is certain; at the time of the increasing market polarization and all the more pronounced joining of the aircraft manufacturers with the certain engine factory, especially in the field of the wide-body aircrafts, one battle remains very present and interesting, and that is the one around the Boeing 787 Dreamliner