Re: Prop mass and bsfc figures for YASim
Andy Ross <[email protected]>
| Newsgroups | gmane.games.flightgear.flightmodel |
|---|---|
| Message-ID | <[email protected]> |
Gerhard Wesp wrote: > Andy Ross wrote: > > A 2D moment of inertia about a point is a mass times a moment arm. > > In YASim's units, that's a kg-m. > > Are you sure this makes sense? How is it going to be used in the > equation for the rotation speed, then? Uh... sorry. Brain fart. :) Yes, it's a kg-m^2, for exactly the dimentionality reasons you explain. So the simple integral for a "stick prop" MOI becomes: mass * radius^2 / 3 Amusingly, this doesn't actually change the answer much for the planes in question (the equations agree at r == 1.5m, which is just about the size of a P-51 prop). I'll fix the docs. Andy _______________________________________________ Flightgear-flightmodel mailing list [email protected] http://mail.flightgear.org/mailman/listinfo/flightgear-flightmodel 2f585eeea02e2c79d7b1d8c4963bae2d