You've been busy this weekend, it's always nice to see the range of aircraft increasing. I'm still on my way to making the CVS work (I'm very busy here), when I do it'll be great to have a go with all these aircraft. If I'm lucky I might get something done on the spitfire model today...
Chris On Sun, 2002-11-10 at 04:42, Michael Selig wrote: > > I have just added a Sopwith Camel to the CVS. Not only does it > include the flight dynamics model, but also there's an external model > from A.F. Scrub! He has granted permission for us to use and release > these with FlightGear under the GNU GPL. > > There's a readme file on the external model from A.F. Scrub in: > ~/fgfsbase/Aircraft/sopwithCamel/Models/uiuc/sopwithCamel/ > > The flight model readme from ~/fgfsbase/Aircraft/UIUC/ is included below. > I've included a blurb about the initial motivation for this model as it > relates some work for the Discovery Channel. > > Regards, > Michael > > ====================================================== > = Sopwith Camel F.1 = > = WWI Fighter = > = for FlightGear with LaRCsim and the UIUC Aeromodel = > = = > = Flight model by: = > = Michael Selig, et al. ([EMAIL PROTECTED]) = > = http://www.aae.uiuc.edu/m-selig/apasim.html = > = = > = External model by: = > = A.F.Scrub "Scrubby PC" ([EMAIL PROTECTED]) = > ====================================================== > > To run, try: > > fgfs --aircraft=sopwithCamel-v1-nl-uiuc > > Files and directory structure required in $FG_ROOT/Aircraft/ to fly the > model: > > sopwithCamel-v1-nl-uiuc-set.xml > sopwithCamel/Models/uiuc/sopwithCamel/cambelg0.bmp > sopwithCamel/Models/uiuc/sopwithCamel/cambelg1.bmp > sopwithCamel/Models/uiuc/sopwithCamel/cambelg2.bmp > sopwithCamel/Models/uiuc/sopwithCamel/cambelg3.bmp > sopwithCamel/Models/uiuc/sopwithCamel/cambelg4.bmp > sopwithCamel/Models/uiuc/sopwithCamel/cambelg5.bmp > sopwithCamel/Models/uiuc/sopwithCamel/cambelg6.bmp > sopwithCamel/Models/uiuc/sopwithCamel/cambelg7.bmp > sopwithCamel/Models/uiuc/sopwithCamel/cambelg8.bmp > sopwithCamel/Models/uiuc/sopwithCamel/cambelg9.bmp > sopwithCamel/Models/uiuc/sopwithCamel/Sop-panel.bmp > sopwithCamel/Models/uiuc/sopwithCamel/camel.txt > sopwithCamel/Models/uiuc/sopwithCamel/cambelg.mdl > sopwithCamel/Models/uiuc/sopwithCamel/sopwithCamel-model.xml > sopwithCamel/Sounds/uiuc/sopwithCamel-sound.xml > UIUC/sopwithCamel-v1-nl/aircraft.dat > UIUC/sopwithCamel-v1-nl/CDfa-06.dat > UIUC/sopwithCamel-v1-nl/CLfa-06.dat > UIUC/sopwithCamel-v1-nl/Cmfa-06.dat > UIUC/sopwithCamel-v1-nl/Cmfade-03.dat > UIUC/sopwithCamel-v1-nl/README.sopwithCamel.html > > These files above come with the FlightGear base package. > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Model description and updates: > > 11/9/2002 - First release: v1-nl > > * Motivation: FGFS and the UIUC aero model were used to develop the > flight model of both the Sopwith Camel and Fokker Dr.1 Triplane. > These models were then used in another simulation with a > collaborator, Brian Fuesz. In that simulation, guns, terrain, > villages, multiple planes, etc were added to simulate the last > flight of the Red Baron. This work was filmed for the Discovery > Channel show "Unsolved History: The Death of the Red Baron" > scheduled to first air Dec 18, 2002. > > * A.F. Scrub ([EMAIL PROTECTED]) has granted FlightGear > permission to use and release the external model files with FlightGear > under the GNU GPL. > > * A weights and balance was performed to arrive at an allowable > c.g. location and from that data, mass moments of inertia were > calculated. > > * Lift, drag and pitching moment data is modeled from -180 to +180 > deg. In general, the aerodynamics are modeled using various > sources. > > * Apparent mass effects are modeled. > > * Gyroscopic forces caused by engine rotation and aircraft rotations > are modeled. For an animation of how a WWI-type rotary engine works, > go here: http://www.keveney.com/gnome.html > An example of gyroscopic forces, are those forces produced when one > tries to rotate by hand a spinning bicycle wheel. > > * Spin aerodynamics are not yet modeled. > > * The simulation starts on the ground. Throttle up to take off or > alternatively, use Ctrl-U to jump up in 1000-ft increments. > > * Interesting flight characteristics to note: > > - The Sopwith Camel was considered a "beast" to fly. It killed 385 > pilots while they were in training (non-combat). In combat, 415 > of the surviving pilots were killed while flying the Sopwith > Camel. Approximately 5000 Sopwith Camels were built, and it is > believed that collectively 1294 enemy aircraft were destroyed. > > - In large part, the challenges to flying the Sopwith Camel involve > the large gyroscopic forces from the rotating engine. Pulling > nose up causes the aircraft to yaw to the right, yaw right and it > noses down, nose down and it yaws left, yaw left and it noses up. > Thus whatever the direction the nose goes, the airplane slews to > the right of that path. This was particularly dangerous for > right-hand turns if not properly managed. The initial roll to the > right takes place without any surprise. But after having banked, > pulling up elevator to turn causes the nose to "slew" to the right > of the intended direction. In this case, it leads to the nose > pointing down, which in turn leads to a tail skid. This skid > could then easily precipitate into a spin. Should that happen, > the gyroscopic forces continue to do their work. If control is > recovered, during the pull out it is very easy to fly on the back > side of the power curve. If that happens, the pullout is very > slow, and it is easy to auger-in. > > - As mentioned in the current sim, spin aerodynamics are not > modeled, so the scenario just described will not happen. However, > the skidding is most apparent. And it is quite easy to fly into > the backside of the power curve from any flight attitude (there is > ample "elevator power"). Keeping the speed up in general is one > way to avoid this regime. > > - Rudder authority on the Sopwith Camel was inadequate, and it only > increased the chances of spinning in. Surely, the designers were > aware of this fact, but a larger rudder would have led to more > weight aft not only because of the shear mass of the tail, but > also because of the larger structure required to support the > larger airloads. This solution surely countered the design > philosophy of trying to put as much weight as possible between the > pilot and engine, all in an attempted to increase maneuverability > by keeping the moments of inertia as small as possible. > > - On takeoff, when the tail raises (nose down rotation) note the > strong yaw to the left attributable to the gyroscopic forces. > > - In general, to stay coordinated in turns requires generous use of > the rudder. > > > > > ************************************************** > Prof. Michael S. Selig > Dept. of Aero/Astro Engineering > University of Illinois at Urbana-Champaign > 306 Talbot Laboratory > 104 South Wright Street > Urbana, IL 61801-2935 > (217) 244-5757 (o), (509) 691-1373 (fax) > mailto:m-selig@;uiuc.edu > http://www.uiuc.edu/ph/www/m-selig > http://www.uiuc.edu/ph/www/m-selig/faq.html (FAQ) > ************************************************** > > > _______________________________________________ > Flightgear-devel mailing list > [EMAIL PROTECTED] > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
