On Mon, 26 Apr 2004 09:54:43 +0200, Mathias wrote in message <[EMAIL PROTECTED]>:
> On Montag, 26. April 2004 00:13, Arnt Karlsen wrote: ..<snip>. > > ..a wee virtual demo on tire side wall flex: Take a parked, say > > Cessna 172, out at the leading edge of the very wing tip, and push > > it straight aft, then release, and repeat. > > > > ..once you get your repeat pushes close to the system resonance > > frequency, you will find wee pushes generates quite a yaw > > oscillation, and that it will swing around a point somewhere near > > the nose wheel. System here, is, tire side wall flexibility (some > > people prefer doing calculus on its inverse, "tire sidewall > > stiffness"), against _parts_ of the wings + tail + nose etc masses. > > What you describe here will most likely not happen with someting only > velocity dependent. ..no? ;-) No velocity, plane is parked. Wee pushes, to exite the resonance. IME, the wee pushes straight aft gets the the plane dancing quite a bit, try it. ;-) > Keep it in your head and try to move your aircraft around its nose ..not around the nose, around the nose wheel, usually around a point somewhere between the nose wheel and the mains. > with that method when we have a better tire model. It you don't get it > turned, we can look if this is doable :-) ..it even works on wet ice in RL. Also for turning the plane around. ;-) ..<snip> > > ..15 feet forward, then back to those marks, will do fine. > > Note how far down the tires crept. Tire creep. ;-) > > This is what I expect to show up with the Pacejka model. Let's see > when this is done ... .. :-) -- ..med vennlig hilsen = with Kind Regards from Arnt... ;-) ...with a number of polar bear hunters in his ancestry... Scenarios always come in sets of three: best case, worst case, and just in case. _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
