On Sat, 27 Mar 2004 22:08:46 -0500, David wrote in message <[EMAIL PROTECTED]>:
> Arnt Karlsen wrote: > > > ..these parameters can be set in a config file? Slowest cranking I > > saw start LN-AEB (a 60'ies PA28-140 with the standard 4-banger > > and quite likely a ditto vintage battery) was a blade every 5 > > seconds. It was usually a blade every 2 to 3 seconds. Facinating. > > ;-) > > So Arnt is suggesting a typical cranking speed of 10-15 rpm, ..typical for an _a_typical plane. ;-) > vs. my ...not too... ;-) > wild guess of 30 rpm. Neither one is blindingly fast. His worst case > example was 6 rpm. ..say 5 thru 300 rpm, for all piston engines. I have _once_ seen an engine unable to fire below 300, my Quadra|JoBu 361, with a pointless chain saw ignition, which served me a tennis elbow after an hour or so of pointless hand propping, it was too heavy for my 24V Sullivan and ripping off the cowling and yanking a string off the flywheel ofcourse had it purring on the first try. The damn thing refused to fire below 3000 rpm, for pointless chain saw safety! > I'll mention again that once the engine fires, the jump to normal RPM > is pretty-much instantaneous -- there's no gradual spin-up over a few > of seconds. ..correct., its over the next few firing cylinder charges, to take them from crank to idle speeds. > > ..do we model the compression's effect on crank speed fluctuation? > > We're a long way from anything like that. Right now, it's basically > just a fancy animation. If we wanted to model engine starts properly, > we'd have to model each cylinder individually. That would also allow > the engine to (possibly) run rough when leaned, based on different > air/fuel distribution to different cylinders, etc. (at least until we > installed virtual GAMIjectors on the fuel-injected engines). We could > also model fouled plugs -- that would encourage fgfs users to do a > proper runup before every flight. .. ;-) -- ..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
