Skywatcher
Captain
Could see noticeable tradeoffs in maintenance needs though.
Skywatcher
Captain
The 5:1 ratio between the lenght and diameter is roughly similar to the ratios found on the EJ-200 (74 cm and 4 meters) and M-88 (70 cm and 3.5 m). The question about the F-3's engine is, what is the T/W ratio.
Though I think that the turbofans with greater lenght to diameter ratios might be less fuel efficient, IIRC... Would also require much higher heat tolerance in the turbine blades, which raises weight and resilience issues.
EDIT: You could extend range by turning it into a combined cycle, but that could add on 5 years or so to development.
Though I think that the turbofans with greater lenght to diameter ratios might be less fuel efficient, IIRC... Would also require much higher heat tolerance in the turbine blades, which raises weight and resilience issues.
EDIT: You could extend range by turning it into a combined cycle, but that could add on 5 years or so to development.
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SamuraiBlue
Captain
And what would that be?
Please elaborate.
XF9 is the second military engine utilizing CMC with the first being XF5 that powered ATD-X.
As for weight, since Silicon Carbite (SiC) being lighter than Titanium alloy doped with molybdenum and other rare earth material, theoretically XF9 would be much lighter in weight than conventional military turbo-fan engine utilizing conventional Titanium alloy.
It also handles much higher engine core temperature with XF5 reaching 1,650℃ and XF9 reaching up to 1,800℃ where conventional engines peaks at around 1,450℃.
Skywatcher
Captain
Using new materials; speaking from general engineering principles, if you use an entirely new material for applications, there is going to be a lot of need for intense maintenance as you build up a working knowledge.
The EJ200 hits about 1580 Celsius, and I can only imagine what the F119 actually is.
SamuraiBlue
Captain
Why?
You'll really need to elaborate this one since new application does not always means it requires more maintenance. Without some actual reason you are only generalizing a very specific situation.
CMC has been heavily tested in both commercial and military application for jet engines through GE and development of XF5.
Really, didn't know that but it still is lower than the FX5 1,650℃ mark.
Simple, you have no data on Mean Time to Failure. What is the time between cracks/fatique to appear on one of the blades. Much more frequent of close examination like x-ray will be needed
SamuraiBlue
Captain
That is something GE, Boeing and other research labs would be looking at first.
Do you have lab results that we can compare with conventional material?
Boeing is not going to place something on their plane without literally scrutinizing with a microscope first.
That's nonsense. You are not using new materials and ship them with a product and just wait how it turns out. Especially not in the aerospace field where everything needs to be certificated and proven.
