Questions tagged [turbofan]
A type of jet engine which uses two different airflow streams (one passing through the core and another blown past it by a fan) for obtaining thrust.
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Why would a jet engine use cannular combustors if the annular design is superior?
Why are cannular type burners used in aircraft engines if annular type have more advantages over it?
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How does a fan differ from a propeller?
Why is the fan in a turbofan different than a propeller in a small airplane? Why do propellers typically have 2 or 3 blades, but the fan has a lot more? And why is the fan shrouded but the propeller ...
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Just how much power (as a percentage) is necessary to drive a compressor in a jet engine? [duplicate]
If i understand correctly this is the "back work ratio". I'd like to know how much % of the "gross" thrust is used by the turbine to drive the compressor in a typical turbofan.
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Which are typical rpm values for aeronautical turbines?
I wonder which of these has higher or lower rotational speed:
turboshaft
turbofan
turbojet
turboprop
Does anybody know the typical speeds for these kind of engines?
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Why are the fan blades mounted loosely?
In this question it is mentioned that the fan, compressor and turbine blades are mounted loosely in the disc. This is well demonstrated by this video posted by RedGrittyBrick.
What is the reason for ...
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What cargo airplanes can transport fully assembled large turbofan engines? [duplicate]
Is there a big demand for transporting overseas for turbofan engines with nacelles like TrentXWB or GEnx by cargo airplanes ? If yes, what planes are used?
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Would a drone strike be more dangerous than a bird strike?
Let's say you have a seagull and a drone of a comparable size. Pretend either one was going to be ingested by large turbo fan engine, like the one found on a 737 (eg., the CFM-56)
Which would cause ...
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In a turbofan what holds the spinning axis?
When the turbofan is spinning inside the housing, what holds the axis? All I know is that the axis holds the fan blades.
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Is it possible to build a turbojet engine with aluminum cans? (Soft drink cans)
I'm interested in building a working model of a turbojet engine, but I don't have a lot of supplies. So I'm wondering if it's possible to use aluminum cans for construction, for every body part. While ...
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What is the major source of engine noise for non-propeller aircraft?
Sparked by this question:
Take any non-propeller powered aircraft, when idle, the sound produced by the engines are fairly low pitched, and as the engine spins up, increasing in pitch before becoming ...
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What drives and/or allows the move to higher-bypass turbofans on jetliners?
Note: I'm by no means an expert on any of this, I'm just curious.
There seems to be a general trend toward higher and higher bypass ratios in commercial jetliner engines. (I'm thinking here of 737/...
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What is the bypass air in a turbofan engine actually for?
I'm planning on building a small model turbofan engine for a bit of fun but I thought I'd better get a better understanding of how they work first. I understand the majority of it at the moment but I'...
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How much power is drawn by a turbofan to power its own compressor?
In a modern commercial airliner how much percentage of its engine power is used to power its own compressor, the ducted fan and other ancillaries like the airconditioning etc? Maybe it can't be ...
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Why do military turbofan engines use a low bypass ratio?
I know that the most civilian engines use a high bypass ratio which is good for fuel economy and noise reduction.
What prevents military engines from using the same technology instead of opting for ...
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Off-center fan in geared turbofan - does this exist?
Has anyone ever heard of a geared turbofan in which the axis of rotation of the fan is offset from (i.e. not the same as) the axis of rotation of the turbine? In all the current geared turbofans I've ...
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Why are turbofan inlets circular- or oval-shaped instead of square-shaped?
Source: materialsengineeringconsultant.com and initious.blogspot.com.
Most of the engines are circular except for some that are oval. The oval shape provides a better ground clearance.
Why aren't ...
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How does the shape of the blades on N1 fan on a turbofan generate thrust?
A propeller generates lift, which results in prop-wash for thrust(same as helicopters), but when you look at the N1 fan it looks much different than propeller blades. Do turbofan blades generate lift ...
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How does this vortex form inside a jet engine?
I have seen this in a picture once online and thought it was very strange and wondered about the formation of this vortex and how could it happen.
Source
Not everyday do you see this happening. So ...
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What methods are used to make a turbofan engine spool up quicker? [closed]
In cases such as a low altitude stall the quick application of power might get a pilot out of a sticky situation, but turbofan engines are fairly sluggish in increasing thrust. If throttle is applied ...
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Why do turbofan engines have low pressure compressors?
In my understanding turbofan engines usually have 2 stages of compressors:
one low pressure compressor
followed by a high pressure compressor
But it looks like the high pressure compressor ...
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Why are turbofan inlets leaned/angled forward?
(Image Source: Wikipedia)
Seeing that everything is radially symmetric (apart from the nacelle mount, naturally), I wonder why the inlet (the front part of the nacelle) is usually skewed?
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What provides the greatest thrust in a high-bypass turbofan engine?
I'll try to make as much sense as I can with this question.
I've been flying quite often in 2015, and I have recently wondered this question regarding high-bypass turbofan engines. I know that there ...
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Electric Airplane - Hybrid / dual type engines how would that work?
If you have an airplane with electric propellers for take off and landing and you have a turbofan/jet to reach higher speeds for cruise.
For example, electric propellers can go to 250mph and turbofan ...
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Why does an aircraft as big as the Airbus A400M use turboprops?
Why is it that a plane as big as the C-17 (the A400M is slightly smaller though) use turboprops instead of turbofans? Both aircraft seem to have the same purpose and are both capable of landing at ...
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What is the use of saw-teeth present on the nacelle outlets of modern turbofans? [duplicate]
I've noticed that there are saw-teeth on modern jet engines such as the GEnx and the Rolls Royce Trent 1000. What is their purpose?
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Why do turbofans have different nozzles?
The CFM 56-7BE (on the 737) has a long and narrow nozzle, the RR Trent 900 (on the A380) has a sharper nozzle, and the CF-6 (on the 767) has a wider opening at the nozzle. Why do the nozzle sizes vary ...
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What are the limitations in adoptions of GTF (Geared Turbofan) technology?
The only recent engine using GTF technology is the PW1000G, however some old designs like ALF502 or TFE731 use this technology. I understand the basic concept of the benefit obtained by the engine ...
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What is the difference between a turbofan and a turboprop engine?
I'm not an aircraft expert and I just realized that there are two different terms - turbofan and turboprop. I always had them combined in my head as a term for a large jet engine (like you would see ...