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JetDriverWannabe
3rd Mar 2005, 12:10
Exhuast Velocity of of Jet Engine at cruise ?

Whats the velocity of the exhuast gas comming out of the end of a typical High by pass ratio engine on a jet liner at cruise ?

Assuming the following cruise conditions. What would the exhuast velocity be?
35,000 feet
450 Knots TAS


What about the exhuast velocity of jet engine from a supersonic jet liner in the following conditions?
55,000 feet
1200Knots TAS

enicalyth
4th Mar 2005, 11:30
Try http://www.aircraftenginedesign.com which is Jack Mattingly's website. I know you asked for specifics but it is much better to find out how to do things yourself. Unfortunately Jack gets some things wrong from time to time like all authors. Only by working at your craft can you pick up on stray blunders. Barnes McCormick is another good author except when he gets onto ideal cruise speeds.... in one of his exercises for a well-known brand of turboprop he recommends a cruise speed that would demand a lift coefficient of 0.905. Wow! Cruising with flaps!! Now what would that do to drag? It certainly wouldn't maximise L/D!! So by all means buy the books and do the freebie downloads but don't accept answers from them or anyone else uncritically. Too, too many people bang on about the craft without building up a really solid base ability of being able to do things for themselves and get it right. Thanks for the question, I've suggested tools for the job and wish you luck and happiness in achieving your goals.

References Aerodynamics, Aeronautics and Flight Mechanics
by Barnes McCormick ISBN: 0471575062

Elements of Gas Turbine Propulsion by Jack D Mattingly ISBN: er, mislaid it in Bangkok...

Mechanics and Thermodynamics of Propulsion (2nd Edition)
by Philip Hill, Carl Peterson ISBN: er, left it at home

swh
4th Mar 2005, 14:57
The Trent exhaust velocity is about 1050 mph out the back

:ok:

james ozzie
5th Mar 2005, 08:00
Is this leading to the question that vexed early anti-space travel sceptics. viz how can a rocket fly faster than its own exhaust velocity???

ShyTorque
5th Mar 2005, 09:10
Is it about the same as the airspeed velocity of an African Swallow? Without a coconut of course.. ;)