2011/6/19 Ron Jensen <w...@jentronics.com>: > On Saturday 18 June 2011 21:00:41 Jon S. Berndt wrote: >> Here's an example from Hal's P-51D Mustang. This is from an old version, so >> it may have changed by now, but it illustrates the approach. In the >> <aerodynamics> section of the config file - but outside of any <axis> >> element - is this definition of qbar due to propwash: >> >> [Note: <v> is shorthand for "value", and <p> is shorthand for "property".] >> >> <function name="aero/thrust-qbar_psf"> >> <product> >> <v> 0.5 </v> >> <p> atmosphere/rho-slugs_ft3 </p> >> <pow> >> <sum> >> <p> velocities/u-aero-fps </p> >> <product> >> <p> propulsion/engine/prop-induced-velocity_fps </p> >> <v> 2.0 </v> >> </product> >> </sum> >> <v> 2.0 </v> >> </pow> >> </product> >> </function> > > I recently added this function to the A6M2 Zero. I placed it on CYdr (rudder > yaw) and dCLdf (flap lift delta) as well as CMde. It makes the plane fly > much, much better during the initial takeoff roll. It probably should be used > with CMdf (pitch due to flaps) as well. > > But why are you multiplying propulsion/engine/prop-induced-velocity_fps by 2? >
The total velocity of the air flow in the far slipstream is V+2*w where V is the velocity of the airplane and w is the induced velocity as computed by the momentum theory. See the following discussion in the JSBSim mailing list : http://sourceforge.net/mailarchive/forum.php?thread_name=201004181833.32417.ghmalau%40gmail.com&forum_name=jsbsim-devel Bertrand. ------------------------------------------------------------------------------ EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
