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
)
