On Tue, 2002-11-12 at 23:45, Sander Pool wrote: > > When I read that the fins failed I paid closer attention to the fin design > as far as I could see it in 'before' pictures. This made me wonder why such > a conventional, low speed fin was chosen. I'm no rocket specialist but I do > believe in the old school philosophy "if it looks fast it will go fast". If > I was to build a rocket that was going to go close to Mach 1 I would have a > fin that is much more swept backwards. Why was a relatively straight fin > chosen? Does this have low speed advantages? Perhaps fins that are more > swept really are not more resistant to high speed flight for the same > surface area compared to straighter fins?
Actually that shape is used on sounding rocket boosters going supersonic. I think the real problem was the thickness or rather the thinness of the fins. Also the fins were overlarge for the vehicle. More sweep with a longer root and smaller span would have also helped. We actually saw a potential problem with the fins and cancelled a 10 liter flight before we even went out there. (There were other reasons for cancelling that flight as well, but the calculated fin limitations pretty much shut down any further discussion.) Now we need to figure out the difference between the fin flutter model and reality. Dave _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
