Q: Turbofan rpm at N1 100% for a CFM56-5B4
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Q: Turbofan rpm at N1 100% for a CFM56-5B4
Just curious...
For a CFM56-5B4 engine (typical for an A320):
What would be the approx. rpms of the turbofan at a N1 of 100% ?
Thanks in advance.
For a CFM56-5B4 engine (typical for an A320):
What would be the approx. rpms of the turbofan at a N1 of 100% ?
Thanks in advance.
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I managed to answer my own question:
5200 RPM (max N1 at 104%).
Source:
http://www.aftd.com/TCDS_PDFS%5CE37NE_10.pdf
5200 RPM (max N1 at 104%).
Source:
http://www.aftd.com/TCDS_PDFS%5CE37NE_10.pdf
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Re: Q: Turbofan rpm at N1 100% for a CFM56-5B4
Originally Posted by Tonic Please
Only 5200 RPM at max power? I'm very suprised. Considering cars do that with a significant engine rev. 
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Re: Q: Turbofan rpm at N1 100% for a CFM56-5B4
So its the middle of the fan going 5200? Or something else? What is used to come up with the speed?
A-FLOOR, made me chuckle
Supersonic speeds on the tips? Bloody hell.
A-FLOOR, made me chuckle
Supersonic speeds on the tips? Bloody hell.
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Re: Q: Turbofan rpm at N1 100% for a CFM56-5B4
Originally Posted by Tonic Please
Exactly, so how can the tips be going "supersonic"?
Revolutions per minute may be the speed the shaft is turning at, but it is not the speed through the air that a point on a disc on that shaft is achieving.
PP
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Re: Q: Turbofan rpm at N1 100% for a CFM56-5B4
The numbers say:
Fan diameter is 67" or 5.6 feet. The state of Arkansas has legislated that pi=3, so I'll use that to find the circumference is 16.8 feet. And the blade tips travel 16.8 feet every revolution.
Speaking of revolutions, if we do 5200 in a minute, that's 83 in a second.
So - 16.8 feet in revolution, and 83 revolutions in a second, so it's about 1400 feet per second, without even considering the vector addition of incoming flow.
Sound travels 1100 feet per second on a standard day, so yes, the tips are supersonic. About 1.3 times the speed of sound.
I need a beer.
Fan diameter is 67" or 5.6 feet. The state of Arkansas has legislated that pi=3, so I'll use that to find the circumference is 16.8 feet. And the blade tips travel 16.8 feet every revolution.
Speaking of revolutions, if we do 5200 in a minute, that's 83 in a second.
So - 16.8 feet in revolution, and 83 revolutions in a second, so it's about 1400 feet per second, without even considering the vector addition of incoming flow.
Sound travels 1100 feet per second on a standard day, so yes, the tips are supersonic. About 1.3 times the speed of sound.
I need a beer.
Re: Q: Turbofan rpm at N1 100% for a CFM56-5B4
Originally Posted by barit1
The numbers say:
The state of Arkansas has legislated that pi=3,
The state of Arkansas has legislated that pi=3,
That figures, them hicks are trying to go metric down there
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Re: Q: Turbofan rpm at N1 100% for a CFM56-5B4
Nope, it was long before that evil communist plot.
And I found a source postulating it was Indiana, not Arkansas:http://arshermeneutica.org/besieged/...the_Vaue_of_Pi
(WHOOP WHOOP thread creep detected!)
And I found a source postulating it was Indiana, not Arkansas:http://arshermeneutica.org/besieged/...the_Vaue_of_Pi
(WHOOP WHOOP thread creep detected!)
