[AR] Re: Propellant tank idea
- From: Paul Mueller <paul.mueller.iii@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Tue, 27 May 2014 13:09:28 -0600
Also, Luxfer makes lots of different-sized cylinders (if you need bigger
ones) that you should probably be able to turn on a 10x36 lathe (I think
that's kind of a standard size for floor-mounted lathes). Overwrapping the
barrel section of the tank with composite is also relatively easy for added
strength.
Paul M
On Mon, May 26, 2014 at 8:47 PM, Robert Watzlavick <rocket@xxxxxxxxxxxxxx>wrote:
> As some of you may recall, I've been trying various ideas to fabricate
> propellant tanks for the rocket I'm working on. I think I've come across
> something that should work good enough for my first liquid rocket - an
> E-size aluminum oxygen cylinder with the OD turned down a bit. These
> cylinders have quite a bit of wall thickness since they are rated for 2015
> psi. They are normally hydro tested to 5/3 (3358 psi) and burst tested to
> at least 2.5x (5038 psi). I'm running it at 500 psi so I only need a 0.052
> inch wall for a 2x factor of safety. The only thing is that it isn't
> completely round, about 0.03 out of round. I chucked one up on the lathe
> and took off 0.125 of the wall over part of it, cut out a section, and
> measured a resultant wall thickness of between 0.082 to 0.120 (I didn't
> center it as well as I could have). The original wall was about 0.215
> inches. The original weight is 7.8 lb and I think I can get it down to
> about 4 lb without extraordinary effort (such as re-profiling the neck,
> etc). There is plenty of thickness at the bottom for a 3/8 o-ring boss
> fitting and I already have a design for the top threaded fitting since I
> used one on my original test stand. For my 250 lb LOX/kerosene engine, I
> should be able to get a maximum of 15 seconds of run time, more than enough
> for an unguided rocket (I'm thinking 5-10 sec for the first flight).
>
> I'm going to have to give up on the idea of internal passageways through
> the tanks for now. Since I need to route the upstream tank lines around
> it, this drives my vehicle OD from 5 to 6 inches but for a nominal 8-10
> foot long rocket, it's probably ok.
>
> -Bob
>
>
>
>
Other related posts: