[AR] Re: Question for the solids guys...

  • From: "rcktman" <dmarc-noreply@xxxxxxxxxxxxx> (Redacted sender "rcktman" for DMARC)
  • To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx>
  • Date: Thu, 03 Dec 2015 16:22:06 -0500

I've seen Marmon clamps and e-beam welds (of dissimilar metals).

bill


Sent from my Commodore 64.



-------- Original Message --------
Subject: [AR] Re: Question for the solids guys...
Local Time: December 1 2015 7:27 pm
UTC Time: December 2 2015 2:27 am
From: wikkit@xxxxxxxxx
To: arocket@xxxxxxxxxxxxx

Related question, anyone have any good references for how a refractory

metal radiative nozzle extension is typically attached to a regen

liquid chamber?



On Tue, Dec 1, 2015 at 9:16 PM, Troy Prideaux <GEORDI@xxxxxxxxxxxxxxxx> wrote:

I’d be surprised if a typical expansion cone (especially most of a high

expansion cone) was constructed of carbon-carbon. Throat – yup, sure, but as

I’ve said previously - a very substantial fraction of a high expansion cone

will see relatively low temperatures and extremely low pressures. No I

haven’t constructed a vacuum optimised solid expansion cone, but if I did,

I’d do it exactly the same way I’ve been making my nozzles for the last 20

years – graphite throat with carbon-fibre/phenolic composite expansion

section and yes I could do it for a reasonable flight weight without too

much fuss. Sure, if the burn time was reasonably long or motor was of

substantial enough impulse, then I might have to implement a carbon-carbon

throat and take extra measure to handle the thermal energy.



To illustrate just how cold the exhaust flow can get for vacuum optimised

expansion – a typical LH2:LOX engine that’s being expanded to something

close to vacuum conditions will form *icicles* on the aft edges of the

expansion cone.







Troy







From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On

Behalf Of Paul Breed

Sent: Wednesday, 2 December 2015 12:31 PM

To: arocket@xxxxxxxxxxxxx

Subject: [AR] Question for the solids guys...







If one was going to build a solid vacuum stage,



has anyone on this list built a flight weight high expansion ratio solid

motor?







Clearly just turning a steel or graphite solid expansion cone is either low

expansion ratio or not flight weight.



If its a simple long tubular solid the expansion cone is going to have to be

bigger than the case diameter....







Looking at professional vacuum stage solids one sees carbon carbon expansion

bells and fuel geometries that aren't the simple tubular solids that typify

the amateur solid...



Like:

http://104.131.251.97/spacerockets/wp-content/uploads/sites/17/2015/08/9166357_orig.jpg

)































Other related posts: