Go Back  PPRuNe Forums > Aircrew Forums > Military Aviation
Reload this Page >

Bell unveils new VTOL concepts

Military Aviation A forum for the professionals who fly military hardware. Also for the backroom boys and girls who support the flying and maintain the equipment, and without whom nothing would ever leave the ground. All armies, navies and air forces of the world equally welcome here.

Bell unveils new VTOL concepts

Old 2nd Aug 2021, 19:14
  #1 (permalink)  
Thread Starter
 
Join Date: Feb 2006
Location: The Alps
Posts: 2,711
Bell unveils new VTOL concepts

https://news.bellflight.com/en-US/20...ry-application



chopper2004 is offline  
Old 2nd Aug 2021, 21:10
  #2 (permalink)  
 
Join Date: May 2011
Location: NEW YORK
Posts: 1,228
An more informative illustration is here: https://www.helis.com/database/news/...-usaf/?noamp=1

If I understand it correctly, the idea is to have a jet propelled tilt rotor with folding blades .
etudiant is offline  
Old 2nd Aug 2021, 22:12
  #3 (permalink)  
 
Join Date: Oct 2013
Location: UK
Age: 40
Posts: 539
I wouldn't like to be the guys doing the fatigue analysis on those rotors when in the folded position. I think the blades could be made better use of in the open position in cruise. Each blade is likely to be separately actuated and therefore could be set to minimum drag and also act as a useful lifting surface. The drag in this arrangement may not outweigh the drag in the folded arrangement.
unmanned_droid is offline  
Old 3rd Aug 2021, 00:52
  #4 (permalink)  
 
Join Date: Oct 2007
Location: A better place.
Posts: 2,130
Translation from stowed high speed flight to rotorborne flight could be interesting.
The Osprey doesn't fold it's rotors - and it transitions from a mid-speed turboprop to a helicopter by trading thrust vector for lift - right?
But this thing would transition from pure jet, through turbo-prop to helicopter.
What speed would you need to decelerate to, to be able to fully deploy (presumably) feathered rotors into the airstream, yet still support the vehicle's weight in wingborne flight?
Actuators would need to be very powerful to deploy long rotors into an airstream that would have to be fast enough to support wingborne flight at vehicle MAUW and the rotors would have to be damn stiff and strong to withstand that airload.
Is it then a gradual transition from turbojet to turboprop mode - increase in pitch - thrust from jet exhaust transitioning to propeller thrust?
Am I missing something here?
Can't quite picture how the transition between modes of propulsion would work... but then I'm no aerospace engineer.

Last edited by tartare; 4th Aug 2021 at 00:32.
tartare 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 - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.