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5 votes

I'm having a hard time conceptualizing this statement from "The Jet Engine" by Rolls-Royce

Variable pitch propellers can help explain this. When the aircraft speed is slow, the blade pitch is finer. At faster air speeds the blades must be opened more in the direction of the airstream. This ...
Robert DiGiovanni's user avatar
4 votes

Lightoff to speak about an engine start

It's one of those quirks of the English language. From the Cambridge dictionary - use of "off" to start a process: "To begin by doing something, or to make something begin by doing ...
John K's user avatar
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4 votes
Accepted

Why cant all planes use the best engines like the GeNX or the Trent XWB?

Why doesn't Airbus certify airplanes with the best engine in the market? For example, the A330 had a General Electric CF6-80E1 engine which was very small for it Because when the A330 was first ...
sophit's user avatar
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3 votes

Why cant all planes use the best engines like the GeNX or the Trent XWB?

All commercial aircraft use the best engine technology available at the time when they were being designed. Once the design is settled (after years of work!) an engine change would reset the whole ...
niels nielsen's user avatar
3 votes

Is it a good idea to increase exhaust duct length?

Would the motor be more efficient at generating thrust? No. Both the inlet's and the exhaust's lengths are already optimised for cruise conditions, which is where the engine is going to spend most of ...
sophit's user avatar
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2 votes

Lightoff to speak about an engine start

This would be best answered on English Language and Usage, but I see they already suggested to use Aviation. So this answer. Off has several meanings, including distance or suddenness and being out. ...
mins's user avatar
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2 votes

Why cant all planes use the best engines like the GeNX or the Trent XWB?

Define "best". Best for what? If there were a single universal "best", nothing else would exist. As already said, aircraft use engines that are available when the type gets ...
jwenting's user avatar
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1 vote

I'm having a hard time conceptualizing this statement from "The Jet Engine" by Rolls-Royce

Picture 3.9, which is related to the text you copied in your question, is helpful in understanding the concept: First of all note that with "inlet" they mean the beginning of the axial ...
sophit's user avatar
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1 vote

How do tubojets compare to afterburning turbofans in terms of efficiency?

How do tubojets compare to afterburning turbofans in terms of efficiency? The 5th slide from this presentation (original plot from Daniel P. Raymer, Aircraft Design: A Conceptual Approach), shows a ...
sophit's user avatar
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