Tech Log The very best in practical technical discussion on the web

Warming Up

Old 27th Jul 2002, 00:24
  #21 (permalink)  
Join Date: Aug 1999
Posts: 5
Likes: 0
Received 0 Likes on 0 Posts
I believed as mentioned here, warm up times have
different meanings for different engines. For the
Trent engines, Rolls is a bit concerned about the
oil system (heat exchangers ect) when the oil is
excessively cold and viscous requiring a 50 deg C
oil temp prior to higher power. Their counterparts at General Electric are not quite so concerned,
-10 deg C for the CFM(if memory serves me right).
But have a look at the oil pressures involved,
normal idle pressure for the Trent is around 70
psi where for the GE (CFM 56, CF6-50, CF6-80)
its' around 20 psi. Viscous oil will have more of
an impact on the Trent when advancing power.

The other reason for warm up more common to all
engines, is to allow the turbine section to
thermally stabilize prior to high power. A good
example at the moment is the CFM56 on the A340,
a great engine but it works hard to get airborne.
For CFM's getting tired, EGT margin becomes
critical and a good warm up period can help
prolong life on wing.

N2 is offline  
Old 29th Jul 2002, 02:35
  #22 (permalink)  
Join Date: Feb 2000
Location: CYZV
Age: 77
Posts: 1,256
Likes: 0
Received 1 Like on 1 Post

Yeah BMEP, particularly if Herman Nelson was on strike. Blow pot time!
pigboat is offline  
Old 29th Mar 2004, 21:34
  #23 (permalink)  
Join Date: Jan 2001
Posts: 154
Likes: 0
Received 0 Likes on 0 Posts
EGT margin, what are the acceptable limits? Are you provided with the data and the OATL?
Johnman 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

Thread Tools
Search this Thread

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.