Go Back  RCU Forums > RC Airplanes > RC Jets
Reload this Page >

Viper Question

Community
Search
Notices
RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

Viper Question

Thread Tools
 
Search this Thread
 
Old 07-10-2002, 02:20 PM
  #1  
jiminy
Junior Member
Thread Starter
My Feedback: (3)
 
Join Date: Jan 2002
Location: North, ON, CANADA
Posts: 19
Likes: 0
Received 0 Likes on 0 Posts
Default Viper Question

Hi All!

Does anyone know whether BVM Viper wings have a "sawtooth" notch in the leading edge.. I have a set that are already covered and was wondering if they were custom made or came like that from BVM at any time..

To elaborate.. the chord of the wing goes down from root to tip but jumps up a bit (like some fighter jets) at a point approximately midspan of each wing panel.

What effect does this have on the flying characteristics..


thanks, Jim
Old 07-10-2002, 03:06 PM
  #2  
Veritech
 
Veritech's Avatar
 
Join Date: Jan 2002
Location: Waterford, MI
Posts: 253
Likes: 0
Received 0 Likes on 0 Posts
Default Viper Question

jiminy,
I have a BVM viper that is very old. It does not have a "sawtooth" notch in the leading edge. However, as I recall the newer versions of the viper did in fact have the the sawtooth notch in the leading edge of the wing.

Mine is the very old version that does not have a hatch in the nose. I think that the newer ones also had a hatch up there as well.

As far as flight characteristics, I remember hearing a long time ago that these new wings help low speed performance but it's been a while and I might not be remembering it correctly.

Hope this helps,
Randy
Old 07-10-2002, 03:49 PM
  #3  
Modelman
Senior Member
My Feedback: (7)
 
Modelman's Avatar
 
Join Date: Dec 2001
Location: Fisher, IL
Posts: 415
Likes: 0
Received 0 Likes on 0 Posts
Default Viper Question

If I remember correctly, didn't BV offer a set of optional "Droops" that could be added to the wing? Maybe the sawtooth you have is a set of the leading edge droops??

Craig
Old 07-10-2002, 04:24 PM
  #4  
aparchment
 
Join Date: Dec 2001
Location: Beautiful Coastal Scarborough, ME
Posts: 820
Likes: 0
Received 0 Likes on 0 Posts
Default sawtooth

Hi Jim:

My Ultra Viper has no such change in the leading edge line. As Craig pointed out BVM used to offer an attachment for the leading edge called "droops" that were supposed to enhance the stall characteristics of the wing.

Presumably on the Viper they caused the outer portion of the wing to have a steeper angle of attach than the inner portion. That way the outer portion of the wing would stall and stop producing lift while the inner portion would continue to produce lift and retain control authority. Just thinking out loud for a second, it's hard to believe that the Viper would benefit from these devices since the AOA with flaperons in the landing configuration must be steeper than the outer wing even with the droops, but I don't know for sure and would certainly defer to an aerodynamic engineer for the last word. As I think through the alternative, it may make more sense for the outer portion of the wing to "keep flying" while the root alternates between stall and producing lift. This would allow the flaperons to continue to function for roll control.

Anyhow, that's my long winded way of saying that the droops were intended to improve stall characteristics.

Antony
Old 07-10-2002, 05:49 PM
  #5  
Modelman
Senior Member
My Feedback: (7)
 
Modelman's Avatar
 
Join Date: Dec 2001
Location: Fisher, IL
Posts: 415
Likes: 0
Received 0 Likes on 0 Posts
Default Viper Question

Anthony,

Adding area to the leading edge of a wing, as with the droops, does increase the stability during slow speed operations. The droops actually do three things... one, they add area to the tip of the wing. Two, they induce an aerodynamic washout to the tip. Especially if the leading edge of the droop is forward and below the leading edge of the wing. Three, again if they're forward and below the leading edge, they create an undercambered cross section at the tip. All of these benefits aid in allowing the tip to continue producing lift at high AOA's, even as the root has reached and passed it's stall angle. Take a peek at an airliners leading edge during take-off and landing. The entire wing morphs into a huge undercambered high lift structure.

Craig

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



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.