On Fri, 2010-02-19 at 10:20 +0100, andrea...@gmx.net wrote: > Hi everyone! > > I think I found a little bug in a couple of JSBSim-aircraft: > The property > /fdm/jsbsim/aero/coefficient/CDde (Drag_due_to_Elevator_Deflection) > > takes negative values when the elevator moves up, so the elevator face > is accelerating the plane. > The wrong code is found in the <model>.xml file: > > <product> > <property>aero/qbar-psf</property> > <property>metrics/Sw-sqft</property> > <property>fcs/elevator-pos-norm</property> > <value>0.059</value> > </product> > > "fcs/elevator-pos-norm" should be turned to an absolute value by > <abs> .. </abs>
Yes, you are correct. There is a property fcs/mag-elevator-pos-rad that gives the absolute value of the elevator position in radians. I prefer using radian or degrees for surface positions since they can be adjusted and used in a more meaningful way. > A list of the compromised models: Thanks. > ------------------- > > Am I right? Yes, drag is a force parallel to the relative wind (direction of travel). Having it negative would imply the relative wind is somehow pulling the aircraft opposite its flow instead of trying to push the aircraft in the direction of its flow. In mathematical terms arctan(lift/drag) is always less than +/- 90 degrees. Ron ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
