Hello,
I have heard that tube fins create a lot of drag (and thus can be used to keep rockets from going too high). I presume the same is true of a ring tail.
In RockSim, I have a model I wanted to add a decorative ring tail too. It has three fins that extend out beyond the ring tail, so the ring tail in RockSim is setup for no pylons. Simply adding the ring tail (no change to the fins/pylons) causes the altitude projections to drop by more than half! Is this consistent with peoples\' experience using ring tails?
In addition, the ring tails contribution to the stability is not intuitive - as the ring tail gets longer, it reduces the stability as if the weight of the ring tail is moving the CG more than the CP is moving. And even when it gets really short (1/4\"), it shows it as having a significant contribution to the stability. Is there a reference somewhere that describes the aerodynamic effects of a ring tail?
I think I\'m going to do the design in RockSim without the ring tail, but build it with it.
Thanks,
David