Andy Ross wrote:
Josh Babcock wrote:

OK, here's the file:
http://home.comcast.net/~jrbabcock/superfort/b29-yasim.xml


Some random notes, before I start running it:

The inbord and outboard engines don't match.  Your inbord ones are
defined to produce 2200 HP at 1000 RPM (which is *monster* engine),
while your outboard ones get 2200 at 2900 RPM (a little over 1/3 the
power of the others).  The inboard ones look typoed to me.

I see that all your propellers have a gear-ratio="0.35" setting.  This
is almost certainly wrong.  The B-29 used big cylinder radials, and as
far as I know no one ever made one of these with with a gearing system
(no point, as pistons that size can't be made to move much faster).
Note also that this doesn't match your (outboard) engine settings.
You have a propeller that wants to sink 1800 HP at 2200 RPM.  But at
that speed the engine would be turning at a shaft-melting 6285 RPM.

The props also have buggy settings for their controller levers.  The
are "power-calibrated" at 2200 RPM, which matches the engine settings
you have.  But the max-rpm value is only 1200, so the governor will
never allow them to turn that fast.

I'll try these changes as soon as I get a chance and see what happens.

Andy


_______________________________________________ Flightgear-devel mailing list [email protected] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d


Yeah, I'm still messing around and I don't really understand what I'm doing. The .35 gear ratio came straight out of the POH, and I think I recall seeing a cutaway photo of this engine with a gearbox behind the propeller. The engine rpms should be 2900, I'm not sure how that 1000 got in there. The weird controller lever setting are me grasping at straws.


Should the prop rpm figures be in prop rpm or engine rpm? I took some of the engine figures and multiplied by .35 whet I set some of those.

Thanks,
Josh

_______________________________________________
Flightgear-devel mailing list
[email protected]
http://mail.flightgear.org/mailman/listinfo/flightgear-devel
2f585eeea02e2c79d7b1d8c4963bae2d

Reply via email to