Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
SHP Vs Lbs Thrust  
User currently offlineParapente From United Kingdom, joined Mar 2006, 1557 posts, RR: 10
Posted (6 years 7 months 1 day 17 hours ago) and read 10229 times:

Prop engines are measured in Shaft horse power. Fan engines are measured in Lbs of thrust. The 2 are different. How does one compare the relative thrusts of 2 engines. Is there a formula?

3 replies: All unread, jump to last
 
User currently offlineJetMech From Australia, joined Mar 2006, 2687 posts, RR: 53
Reply 1, posted (6 years 7 months 1 day 15 hours ago) and read 10217 times:



Quoting Parapente (Thread starter):

Check out this thread and see if your answer is there  Smile .

Engine Power (by LH748i Nov 6 2007 in Tech Ops)

Regards, JetMech



JetMech split the back of his pants. He can feel the wind in his hair.
User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2546 posts, RR: 24
Reply 2, posted (6 years 7 months 1 day 14 hours ago) and read 10207 times:

Strictly speaking it is engines which develop shaft power which are measured in SHP. Aircraft jet engines don't so are measured in thrust units.

It is easy enough to convert power to thrust, or vice versa, but you need to know propeller efficiency as well. You could fit a more efficient propeller onto an engine and get more thrust from it, but the power output of the engine would be the same.



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineBuzz From United States of America, joined Nov 1999, 697 posts, RR: 21
Reply 3, posted (6 years 7 months 16 hours ago) and read 10111 times:

Hi Parapente, Buzz here. There are conversion formulas, we used to grind through them when I was going to college. I haven't used them in years... So for an accurate answer, see what JetMech, and Jetlagged have posted.

For a very rough approximation, 60% of the horsepower is more or less the pounds of thrust. Of course, it makes a difference if you're at cruise speed (and altitude), or waiting at the end of a runway and hoping you have enough power to take off. (grin) Propellers are more effective at low speed - move a larger mass of air more efficiently.
Those little Bede BD-5's with the tiny jet engine worried me - can it get up to flying speed before the end of the runway?

g'day


Top Of Page
Forum Index

Reply To This Topic SHP Vs Lbs Thrust
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
How Is Lbs/thrust Computed? posted Mon Mar 18 2002 20:10:13 by Norseman
Thrust VS. Horsepower? posted Thu Nov 29 2007 09:55:27 by BR715-A1-30
Engine Thrust: Rating Vs. Real Differences posted Sun Sep 24 2006 20:49:42 by A342
GEnx Demonstrates 358 Kn/80500 Lbs Of T/O Thrust posted Tue Mar 21 2006 22:21:16 by A342
Why Have Thrust Reversers At All? posted Sat Jan 12 2008 02:08:02 by Faro
Compression Ratio Vs Turbine Temp posted Sat Dec 29 2007 02:29:11 by Faro
Aborted Landing: 747 Vs A380 posted Tue Dec 25 2007 17:52:08 by Qslinger
Winglets Vs Blended Wings posted Tue Dec 25 2007 11:01:47 by Kamboi
Acmi Vs. Wet Lease posted Tue Dec 18 2007 14:51:54 by Bok269
Thrust Settings For Most Modern Airliners posted Sun Dec 16 2007 10:50:02 by ZSOFN

Sponsor Message:
Printer friendly format