Search the archive:
YaBB - Yet another Bulletin Board
 
   
 
Page Index Toggle Pages: 1
Send Topic Print
Perpeller beanie stuff ..aka Aerodynamics (Read 193 times)
Dec 17th, 2005 at 12:51pm

Grayeagle   Offline
Lieutenant Colonel
Simviation Rocks!
Phoenix, AZ

Gender: male
Posts: 5
*****
 
Hiya Smiley

Like you, I am an airplane nut.
Built tons of models as a kid, built and flew my own designs in U-control and later Radio Control .. then later became a student pilot and now I fly for the fun of it when I can.
Along the way I took Embry-Riddle's perpeller beanie course .. er .. aerodynamics .. and for a time I was paid to build 3d models of aircraft and other bits for video games.

A few things I have learned along the way I thought may be useful to those who like to model these aluminum-fabric-titanium works of art and have them 'fly' fairly well in MSFS.

I am goin to take it for granted that you know the basic terms I use.. if not, just ask Smiley

Most of this applies to the piston engine hot-rods of WW2 ..and most GA types.

CG ..1/4 to 1/3 of total distance from leading edge of the wing. If it's too far forward. . you need massive elevator input to effect a change in pitch.. if its too far back.. elevator is very sensitive and can stall *easy* and often.

Incidence .. planes were designed with 1 degree or more.. up to 5 degrees for the heavy lifters. This is a compensating mechanism ..as speed builds up, lift available increases.. adding to the lift generated by the wing. Planes require nose down trim as speed increases. The benefit is .. if you lose power ..she will trim nose up automatically ..reducing the pilot workload on approach and in some cases compensating a bit for the low-wing flaps trying to pitch the nose down.

Wing twist ..comparing root and tip incidence ..the tip is angled down compared to the root. Planes are designed with 1-3 degrees of it. The benefit is, the wing will stall at the fuselage first, allowing the ailerons to be effective even when most of the wing has stopped flying. Roll control on approach is a good thing.

Something the real spit pilots have to watch for very closely.. due to elliptical wing, the stall wave progresses parrallel to trailing edge ..first indication of a stall in a real spitfire is loss of aileron control.. very bad on approach if you have to add power Sad

Engine thrust .. 1/2 - 1 degree nose down reduces pitch changes when power is applied or cut dramatically. 1/2 a degree to right or left will counter a lot of the P-effect generated by the prop on takeoff roll.

These are some of my favorite things Smiley

-evil grin- ..using these principles ..I modified the Rans RV-8 add-on to emulate a turbo IO-600 (fictional engine) that makes 850 hp ..its an evil little airplane that is a blast to fly, stable as a rock, can hang on the prop ..sort of a poor man's Extra 300 Smiley

-Grayeagle
 
IP Logged
 
Reply #1 - Dec 17th, 2005 at 2:31pm

Felix/FFDS   Offline
Admin
FINALLY an official Granddad!
Orlando, FL

Gender: male
Posts: 1000000627
*****
 
Quote:
Hiya Smiley

Like you, I am an airplane nut.
.....


and for a time I was paid to build 3d models of aircraft and other bits for video games.



There are times when one's two hobbies come together, and this is one of them.

One of the first, if not the first, massively multi-player online WW2 air combat simulations was Äir Warrior.  GE built models and graphics for this game, enjoyed by thousands worldwide.

He was one of the earliest members of the Damned Air Group (founded 1988, and still going strong).  In the finaly years of Air Warrior, when the "airfields" started being assigned names rather then nondescript numbers, "GrayEagle" was one of the much fought after fields...  (sigh, "Felix" was never much more than a lonely jeep/vehicle field from which to spawn vehicles)

Welcome (back) to the madness.....

 

Felix/FFDS...
IP Logged
 
Reply #2 - Dec 17th, 2005 at 4:15pm

Travis   Offline
Colonel
Cannot find REALITY.SYS.
Universe halted.
Dripping Springs, TX

Gender: male
Posts: 4515
*****
 
Welcome to the forums, Grayeagle.  Sounds like you have some amazingly comprehensive knowledge to throw in.  Hope you stick around!  We could certainly use an aerodynamics guru around here . . . (no offense, Felix! Wink)
 

...
IP Logged
 
Reply #3 - Dec 28th, 2005 at 1:39am

napamule   Offline
Colonel
The 'Mechanic'
California

Gender: male
Posts: 10
*****
 
Right on! Grayeagle should hang around as there is a need for 'qualified' (as in real life) aerodynamic mechanics in FS. Ones willing to help, that is. I am sure they're out there, but not redily apparent or accessible sometimes, especially for 'advice'.

I am an aircraft nut (since FS98) too. I tweak cfg and air files since then. But technical specs (the 'why' it works/don't work in FS) is hard to come by. Then there's the 'real' versus the 'FS' version of model and then is when it all goes to pot! But, this is when it also gets interesting. So TWEAK I MUST. Cheers.
Chuck
Edit: So what I am trying to say, is FS need a place to take just released AC's where there is input, then concensus, about what needs changing (ie: tweaking). A place where one can 'take it apart, and put it back together' to where it 'flys' right. Several people (Chicilo, Jones come to mind) are trying to offer 'improvements', but it's their version of how it should fly, (as would be my tweaks too, of course) but not the definitive one. (See 'bouncy-bouncy' post to see just how complicated it all can be). If all of us could put our 'heads together' THEN it would be 'progress'. Otherwise it's just 'jerry rigging' it. Know what I mean?
 
IP Logged
 
Page Index Toggle Pages: 1
Send Topic Print