Jump to content
COMBATSIM Forum

Uneven weight distribution


Mustsafa
 Share

Recommended Posts

As an certified Cesna seat warmer, I noticed that in case of uneven weight distribution on the wings, then banking while keeping the heavier wing bellow should spread air frame stress and improve handling since the center of gravity is still closer to the aircraft.

 

I tried this in F4AF, TAW2 and DCS without feeling difference; am I missing something?

 

I thought of it as two tether balls moving counter-clockwise while the one farther is dismounted, the stress and center of gravity should be closer to the center.

 

 

tether ball.jpg

Link to comment
Share on other sites

Speaking for the F-22: The F-22 flight control system distributes fuel to keep the center of gravity close to the center of the aircraft, especially with regard to payload. This is because curve flight relies little on the control surfaces but heavily on the center of mass differing from the centers of lift and drag.


Speaking for TAW: IIRC, TAW assumes a fixed center of gravity for the F-22. There is a little bit of code to simulate imbalances, but it’s never used and it’s missing recomputation of the moment of inertia.

 

TFXplorer does compute center of gravity and moment of inertia with respect to payload, so that overloading one wing will change flight characteristics. But it’s lacking a weapon selection screen (apart from more substantial things, like gameplay) so that’s of little use. Here’s an overloaded left wing with the plane leaning to the left (got not in-flight footage right now):

2017-09-07%20left%20wing%20overload.png

Link to comment
Share on other sites

I would think of it in terms of fulcrum physics where you have a condition of balanced torque where the load is balanced and lever arm distance is equal on both sides and the Center Of Gravity is therefore established centrally.
At least that is true for TAW which assumes a fixed C.O.G.. When you unbalance the torques (uneven weight distribution) you alter the C.O.G. which could, theoretically, be reestablished closer to the original center by shortening the lever arm on the side of the excess torque and that could be accomplished by a bank (roll), as you suggested. However, in a fixed wing aircraft, a bank would shorten both lever arms and the result would be a counterbalanced effect, although a roll to the side of the heavier weight would also serve to unload that torque to some degree and serve to make the maneouver a bit less than negligible.
All in all, as Krycztij stated, in each of those simulations the resulting response will be solely dependent upon how the C.O.G. is individually computed.

Link to comment
Share on other sites

Ummm, nobody said anything about DCS not modeling this.  All talk has been about TAW.  Falcon simulates a FBW aircraft, so any of this is likely abstracted with the FCS model (not to mention the game is over 20 years old).

 

DCS does model weight imbalance and torque, among other things.  I wasn't a physics major, so I don't intuitively understand the statics and dynamics of which you describe, but I do know that asymmetric loads are modeled, including the CG shift if (for instance) fuel is taken from one tank and not another.  You can try this with the F-5, P-47, and P-51 (or even the TF-51 which comes free with DCS).  As far as handling goes, I would think that adverse yaw (where the high wing in a turn is generating more lift and therefore more induced drag) is a more profound effect for which to compensate.  This is after all why coordinated turns are important.

 

The other flight model that just feels spot-on is the F-14.  Not only are the unique aerodynamic properties modeled (such as the need for rudder rolls at mid-high AoA, high tail buffet at mid-AoA, the Dutch Roll and the first generation SAS that only partially compensates for it), but I would put the flight model next to anything in XP11.  Flying the Tomcat in DCS is one of two near-religious experiences I've had in my 40+ years of flight-simming (the other being a moment in a Falcon 4 campaign that gave me flashbacks of my operational flying days).

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...