Michael Selig writes: > OK, I think I am just getting confused trying to decipher *all* parts of > what you are doing in those files. It's like a puzzle to me.
The JSBSim files can be overwhelming -- they were far worse for me, with no background in aerodynamics (or even physics, for that matter) -- but the top-level arrangement is very simple and similar to UIUC's. There are six top-level sections: 1. METRICS (= UIUC "geometry" and "mass") 2. UNDERCARRIAGE (= UIUC "gear" ??) 3. PROPULSION (= UIUC "engine") 4. FLIGHT_CONTROL (= UIUC "controlSurface") 5. AERODYNAMICS (= UIUC "CL", "CD", etc.) 6. OUTPUT (= UIUC "record") The AERODYNAMICS section contains six AXIS subsections: LIFT, DRAG, SIDE, ROLL, PITCH, and YAW. Inside each of those subsections are definitions for all the coefficients that act on that axis. JSBSim seems more complicated only because it lets you define new coefficients are runtime, rather than hardcoding them in the C++. For example, where UIUC has simply CL CL_adot 1.7 # [/rad] FG c172_aero.c JSBSim has <COEFFICIENT NAME="CLadot" TYPE="VALUE"> Lift_due_to_alpha_rate FG_QBAR|FG_WINGAREA|FG_ALPHADOT|FG_CI2VEL 1.7 </COEFFICIENT> The JSBSim C++ code doesn't actually know anything about CLadot (we could have called it "CLfoobar" if we had wanted), but the effect is the same -- both examples contain exactly the same aerodynamic information. All the best, David -- David Megginson [EMAIL PROTECTED] _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
