about jet engine
Thread Starter
Joined: Jan 2013
Posts: 2
Likes: 0
From: Melbourne
about jet engine
Hi all, i am new to this forum, i just want to ask a question, may be it is quite silly, but still hope someone can answer.
As we know that the lifting force is provided by pressure difference, and by bernoulli equation, the faster the air will decrease the pressure. AND the jet engine is used to accelerate the ambient air to provide thrust. So, will it deteriorate the lifting ability and why not building it above the wing? thank you
As we know that the lifting force is provided by pressure difference, and by bernoulli equation, the faster the air will decrease the pressure. AND the jet engine is used to accelerate the ambient air to provide thrust. So, will it deteriorate the lifting ability and why not building it above the wing? thank you
Joined: Feb 2002
Aviation Qualifications: AME
Posts: 4,183
Likes: 1,119
From: UK
It's called Upper Surface Blowing. (Fnaar, fnaar
)
Or a simpler version (which I used at a job interview by the way
)
Or the complete article..
)Or a simpler version (which I used at a job interview by the way
)Or the complete article..
Last edited by TURIN; 23rd August 2013 at 21:48.
Joined: Jan 2012
Posts: 82
Likes: 0
From: Ontario
Hondajet story
Joined: Jan 2012
Posts: 82
Likes: 0
From: Ontario
YC-14 exhaust over wing
Check out this article on YC-14 and YC-15
1975 | 0193 | Flight Archive
see page 152 also for more details on upper surface blowing on the YC-14.
1975 | 0193 | Flight Archive
see page 152 also for more details on upper surface blowing on the YC-14.
Joined: Aug 1998
Aviation Qualifications: ATPL
Posts: 6,623
Likes: 847
From: Ex-pat Aussie in the UK
... and, of course, just about every business jet ever made along with 90% of tail mount engines on airliners have the engines mounted above the wing.
Joined: Jun 2001
Posts: 4,835
Likes: 85
From: Boldly going where no split infinitive has gone before..
Yes, but usually not to produce a "Blown" wing.
To address the OP, as you can see, it jet efflux CAN be used to produce lift- but producing that lift also produces drag.
Thus it can help in STOL applications, but is less useful when a high cruising speed is desired.
To address the OP, as you can see, it jet efflux CAN be used to produce lift- but producing that lift also produces drag.
Thus it can help in STOL applications, but is less useful when a high cruising speed is desired.
Joined: Dec 2006
Posts: 236
Likes: 1
From: belgium
The upper part of the wing is more important than the lower part in providing lift. Most of the lift is generated by the "sucking" force.
So aerodynamically it's better to leave the upper part of the wing undisturbed, except if you really need it for e.g. STOL designs.
So aerodynamically it's better to leave the upper part of the wing undisturbed, except if you really need it for e.g. STOL designs.
Joined: Mar 2002
Posts: 4,569
Likes: 1
From: Florida
The upper part of the wing is more important than the lower part in providing lift. Most of the lift is generated by the "sucking" force.
So aerodynamically it's better to leave the upper part of the wing undisturbed, except if you really need it for e.g. STOL designs.
So aerodynamically it's better to leave the upper part of the wing undisturbed, except if you really need it for e.g. STOL designs.
