Yep, I'll be here! 7:00 in the conference room in FAB 84.
-Nathan On Thu, Oct 23, 2014 at 10:15 AM, Erin Schmidt <[email protected]> wrote: > Hey guys, > I'm having some rather painful migraines which are leaving me doubtful that > I'll attend tonight's propulsion meeting. AFAIK Nathan is still going, so > tonight would be a good time to actually compare designs in open rocket. > > Keep in mind that changing the fin dimensions or adding ballast to the nose > cone is fair game if your design isn't stable in flight (recall that > stability is a function of the positions of the center of mass and the > center of pressure, both of which are changing dynamically with time, > velocity, angle of attack, altitude, and also with reynolds number and mach > number among other things). It's okay if its not totally stable for the > first half second or so right off the launch rail (assuming that it doesn't > ruin your simulation). If somebody is able to get a legit design to 100 km, > take the burn time and rocket dry mass to get the mass ratio, and plug that > back into the rocket equation to compare with our super simple 1.4 km/s dV > estimate. My bet is it will be 1.5X-2X as high. > > I'm guessing the 100 km rocket with steel tanks isn't doable for us in a > single stage. But I'm curious if we can pull it off with aluminum. We also > assumed a pressure fed rather than pump driven propellant feed system, which > is good because if anything this means our current numbers will be > pessimistic (because we are using a design calling for heavier, high > pressure tanks). I'm hoping this whole exercise will give you an intuitive > appreciation for how ridiculously parameter sensitive rocket design is. > > Ad astra, > Erin Schmidt > > _______________________________________________ > psas-airframe mailing list > [email protected] > http://lists.psas.pdx.edu/mailman/listinfo/psas-airframe > _______________________________________________ psas-airframe mailing list [email protected] http://lists.psas.pdx.edu/mailman/listinfo/psas-airframe
