On Friday 17 Jun 2005 18:05, Jon Elson wrote: > [EMAIL PROTECTED] wrote: > >>..to make formation flight realistic, we also need to model > >> downwash and wing tip vortices. Meanwhile, have fun and > >> join in developing it. ;o) > >> > >> > >> > >> > >> > >>Jetwash too. From what I understand, that can really ruin a > >> nice formation. > > > >Oh, you seem to be experts. I can imagine what effect jetwash > > has (fast hot air surrounded by stagnant cold air). But what > > consequence do wing tip vortices have to the aircraft? Does > > it mean to have more aerodynamic resistance at a specific > > amount of speed? > > There's a pretty famous story of some C-130 (I think) pilots > who rode through a 747's > wingtip vortices about 2 miles ahead of them. Their aircraft > was totally destroyed, > did about 5 rolls, and they were barely able to get it on the > ground in one piece. > I think the wing spar partially broke during the landing, and > the wingtips were > just about touching the ground when they stopped. They were > very skillful in > remaining airborne until they punched through the other side > of the vortices without > causing complete failure of the airframe. > > So, the wingtip vortices have been describes as "awesome > horizontal tornadoes"! > There's a picture that was in the Smithsonian/Air & Space > magazine a couple of > years ago, of an Ag Cat with red dye in the sprayers, and it > painted a 3-d picture > of the vortices trailing it. It was totally awesome, the > vortices formed a pair > of counterrotating funnels whose diameter a little behind the > tail were equal to > the length of each wing! > > Here's some related photos : > http://www.dfrc.nasa.gov/Gallery/Photo/B-727/HTML/ECN-3831.htm >l http://www.professionalpilot.ca/aerodynamics/drag/induced.htm > > I'm still looking for that Air&Space photo on the web. > > Jon
I believe that the fatal crash of a DH Venom at the Biggin Hill 2001 display was attributed to the vortices left by the Vixen performing in the same display. Apparently the Venom's flight control surfaces (ailerons) had insufficient effect to counter the Vixen's vortices. LeeE _______________________________________________ Flightgear-users mailing list [email protected] http://mail.flightgear.org/mailman/listinfo/flightgear-users 2f585eeea02e2c79d7b1d8c4963bae2d
