The current Pratt and Whitney GTF projects are the launched Mitsubishi Regional Jet, with engines from 6,7 to 7,5 t, and the launched but orderless Cseries, with engines from 9,3 to 10,4 t.
PW says that they will not offer GTF over 18 t in near term. But this does imply that they do offer a GTF up to 18 t – much more than the 10,4 t of C130 – in near term.
What would a 18 t GTF be like?
It turns out that the fan diametre of the 10,4 t Cseries GTF is 188 cm.
Too big to fit A321 – the biggest, CFM56-5B3 has just 174 cm diametre fan – and too feeble to lift it, as A321 needs 15 t engine thrust.
The MRJ GTF fan diametre is 142 cm.
So – what would be the fan diametre of an 18 t GTF?
Also, just why shouldn´t an 18 t GTF fit a widebody? Of course not an A350. But it should be quite sufficient for an A340-300. How would a GTF powered A340 compare against A350 with conventional gearless turbofans?
By: tenthije - 15th February 2009 at 20:44
After all, if Pratt and Whitney makes official statements about their wildly hypothetical future plans, it may be hypothetical to ask what they mean with it, but not wildly hypothetical.
You ever considered becoming a politician? You are perfecly qualified by using insanely complicated sentences to say next to nothing. :dev2:
By: OneLeft - 15th February 2009 at 20:31
How the GTF would we know? :confused:
LMAO!
1L.
By: PMN - 15th February 2009 at 15:31
Because I hoped someone would be able to make an informed guess on the matter.
After all, if Pratt and Whitney makes official statements about their wildly hypothetical future plans, it may be hypothetical to ask what they mean with it, but not wildly hypothetical.
More background on how the existing, official, less than wildly hypothetical GTF-s compare against the real, nonhypothetical turbofans.
The closer competitors of MRJ include E-jets.
E-190/195 are powered by GE-CF34-10E turbofans. Thrust 8,2 tons, fan diametre 135 cm.
:confused::confused::confused::confused::confused::confused:
Paul
:confused::confused:
By: chornedsnorkack - 15th February 2009 at 14:05
Because I hoped someone would be able to make an informed guess on the matter.
After all, if Pratt and Whitney makes official statements about their wildly hypothetical future plans, it may be hypothetical to ask what they mean with it, but not wildly hypothetical.
More background on how the existing, official, less than wildly hypothetical GTF-s compare against the real, nonhypothetical turbofans.
The closer competitors of MRJ include E-jets.
E-190/195 are powered by GE-CF34-10E turbofans. Thrust 8,2 tons, fan diametre 135 cm.
By: PMN - 14th February 2009 at 18:50
I am honestly and genuinely at a loss as to why you create these ostensibly pointless threads with wildly hypothetical questions and then proceed to answer them yourself. Absolutely at a loss. Is it just that you’re trying to appear to be smart or what? I really don’t get it! :confused:
Paul
By: LBARULES - 14th February 2009 at 18:43
I think i’ve said it before, but i’ll say it again, I want some of what this guy is smoking!
By: PMN - 14th February 2009 at 14:49
:confused::confused::confused::confused::confused::confused:
And just for good luck…
:confused::confused::confused:
Paul
:confused:
By: chornedsnorkack - 14th February 2009 at 13:57
I think I have a lead to guess it. Disc loading.
An 188 cm diametre fan goes into a square 3,5 sq m area. The circle is of course smaller area (pi/4 times factor) but comparing apples with apples, we should be able to eliminate this.
So, we get 3 tons per square m for C130, and less than this (2,7 tons) for C110. MRJ-s 142 cm diametre fan goes into a 2 square m square, so this is from 3,3 to 3,8 tons per square m. Hm, note that there is a pretty wide range, and that Cseries has clearly lower disc loading than MRJ.
For comparison, the 174 cm disc of CFM56-5B3 goes into 3 square m square, and has 15 t thrust. So, about 5 tons per square m.
Going by 3 t per square m (the higher thrust of Cseries) would give 6 square m for an 18 t GTF. Which means about 245 cm fan diametre.
Far bigger than A321 engines, or B757, or the CFM-s of 340-300. But pretty nicely comparable to the Trent 500 of A340-600. And I understand that the underwing space for roughly 248 cm fan diametre of Trent 500 of A340-600 or Trent 700 of A330 is also present on A340-300.
By: Grey Area - 14th February 2009 at 12:30
How the GTF would we know? :confused:
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February 14, 2009 at 11:58 am