Wikiposts
Search
Spectators Balcony (Spotters Corner) If you're not a professional pilot but want to discuss issues about the job, this is the best place to loiter. You won't be moved on by 'security' and there'll be plenty of experts to answer any questions.

Forward Acting Thrust

Thread Tools
 
Search this Thread
 
Old 31st May 2012, 20:57
  #1 (permalink)  
Thread Starter
 
Join Date: May 2008
Location: Altrincham
Age: 58
Posts: 355
Likes: 0
Received 0 Likes on 0 Posts
Forward Acting Thrust

In How Airliners Fly it shows the workings of a jet engine and states:

"The fan, which is encased in a cowling, forces the compressed air backwards in the form of a jet, much in the form of a domestic electric fan. The engine itself experiences an equal and opposite force and this is the forward acting thrust which propels the aircraft".


If the thrust is coming out forward from the engine, how come the aircraft still flies forwards?
donnlass is offline  
Old 31st May 2012, 21:18
  #2 (permalink)  
 
Join Date: Feb 2002
Location: UK
Age: 58
Posts: 3,500
Received 165 Likes on 89 Posts
Newtons 3rd (I think) law of motion.

For every action there is an equal and opposite reaction.

Propel a mass of air rearwards and the resultant force (thrust) is forward.

Simples.
TURIN is offline  
Old 31st May 2012, 21:53
  #3 (permalink)  
 
Join Date: Feb 2001
Location: The Winchester
Posts: 6,553
Received 5 Likes on 5 Posts
If the thrust is coming out forward from the engine, how come the aircraft still flies forwards?
Read "How Airliners Fly" again. What they are saying is the air expelled from the engine is going backwards, but the thrust (i.e. the force) produced by the engine is acting in a forwards direction, i.e. it's pushing the aircraft forwards.

Last edited by wiggy; 31st May 2012 at 21:53.
wiggy is online now  
Old 31st May 2012, 23:11
  #4 (permalink)  
 
Join Date: Jul 2003
Location: UK
Posts: 461
Likes: 0
Received 0 Likes on 0 Posts
By pushing all that air through the engine rearwards, the engine sucks it way forwards
WASALOADIE is offline  
Old 1st Jun 2012, 09:58
  #5 (permalink)  
Thread Starter
 
Join Date: May 2008
Location: Altrincham
Age: 58
Posts: 355
Likes: 0
Received 0 Likes on 0 Posts
I will do

Thanks all for your patience and replies, I get it now
donnlass is offline  
Old 1st Jun 2012, 10:30
  #6 (permalink)  
 
Join Date: Sep 2010
Location: England
Posts: 1,955
Likes: 0
Received 0 Likes on 0 Posts
Although the action of producing thrust does produce a rearward force in the engine!
Lord Spandex Masher is offline  
Old 1st Jun 2012, 11:29
  #7 (permalink)  
 
Join Date: Apr 2002
Location: Hong Kong
Age: 56
Posts: 1,445
Received 3 Likes on 2 Posts
Isn't there a bloody big vacuum in front of the engine...?
Load Toad is offline  
Old 8th Jun 2012, 16:10
  #8 (permalink)  
 
Join Date: Apr 2009
Location: down south
Age: 77
Posts: 13,226
Likes: 0
Received 1 Like on 1 Post
Although the action of producing thrust does produce a rearward force in the
engine!
Not so I'm afraid.

The compressors and the diffuser section, amongst others, produce forward thrust. The turbine section produces a rearwards force.

Last edited by Lightning Mate; 8th Jun 2012 at 17:30.
Lightning Mate is offline  
Old 8th Jun 2012, 17:29
  #9 (permalink)  
 
Join Date: Apr 2009
Location: down south
Age: 77
Posts: 13,226
Likes: 0
Received 1 Like on 1 Post
This should help your understanding.......

Lightning Mate is offline  
Old 8th Jun 2012, 22:17
  #10 (permalink)  
Thread Starter
 
Join Date: May 2008
Location: Altrincham
Age: 58
Posts: 355
Likes: 0
Received 0 Likes on 0 Posts
Should have a Reply With Quote Button on here but anyway


So the total forward gas load less the rearward gas load produces total forward thrust?

Last edited by donnlass; 8th Jun 2012 at 22:18.
donnlass is offline  
Old 8th Jun 2012, 23:27
  #11 (permalink)  
 
Join Date: Sep 2010
Location: England
Posts: 1,955
Likes: 0
Received 0 Likes on 0 Posts
Although the action of producing thrust does produce a rearward force in the
engine!
Originally Posted by Lightning Mate
Not so I'm afraid.

The compressors and the diffuser section, amongst others, produce forward thrust. The turbine section produces a rearwards force.
So it does then...Unless I missed the bit where my turbine isn't in my engine

Last edited by Lord Spandex Masher; 8th Jun 2012 at 23:28.
Lord Spandex Masher is offline  
Old 10th Jun 2012, 15:18
  #12 (permalink)  
 
Join Date: Apr 2009
Location: down south
Age: 77
Posts: 13,226
Likes: 0
Received 1 Like on 1 Post
So the total forward gas load less the rearward gas load produces total forward
thrust?
Well, if you think I am incorrect, check the Rolls Royce book, upon which my diagram above is based.

If you think it's wrong, then please feel free to put Rolls Royce on the right track!!!!
Lightning Mate is offline  
Old 10th Jun 2012, 18:58
  #13 (permalink)  
Thread Starter
 
Join Date: May 2008
Location: Altrincham
Age: 58
Posts: 355
Likes: 0
Received 0 Likes on 0 Posts
No I dont think you're wrong at all, am not qualified to think that
donnlass is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.