On Sun, 25 Apr 2004 17:46:25 -0500, Jon wrote in message <[EMAIL PROTECTED]>:
> > ..ok, time for another of my stupid questions: Mathias, does your > > new model code include tire creep? And tire sidewall flex? > > There are a lot of tire effects that might be modeled. The question > faced in deciding what to model is: given the purpose of this FDM, > what should be included to achieve the desired effect? There are some > great technical papers hosted in the NASA Langley (and perhaps NASA > Dryden) technical report servers. Several years ago when I was doing > some initial R&D for the JSBSim gear model I had some discussions with > Bob Daugherty of NASA Langley about gear modeling (where they do a lot > of very serious gear modeling and analysis), and he also referred me > to some papers. The range of characteristics that might be modeled > include tire slip, tire "wind-up", spin up, and complex strut > interactions, to name only a few of the more difficult ones. These > problems are difficult even for detailed engineering sims, and in the > case of trying to model any generic vehicle, these problems are > compounded. There are some things I'd like for us to model, but JSBSim > also hopes to remain comprehensive and comprehensible at the same > time, so modeling some of the more subtle effects probably is not > worth the effort. In any case, Mathias and I in particular are working > on some sweeping changes for JSBSim that ought to make the gear > modeling much more stable. After that, there are many other > improvements to make - one of which is looking at the gear model to > discern where improvements can (and _should_) be made. In the > meantime, we are discussing some changes that might be made and doing > some limited research into the matter, including reviewing the > approaches used by other simulators such as racing sims. ..good. :-) Also, keep that compresses doughnut of compressed air in mind, as in; spin up a pressurized tire for at least 3 minutes, then stop-it-n-yank-it-off-that-shaft and try carry it around. ;-) -- ..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
