I wonder if any of these issues caused them to abandon what was a fairly
successful launch vehicle.
K
On Wed, Oct 21, 2020 at 8:18 PM Henry Spencer <hspencer@xxxxxxxxxxxxx>
wrote:
On Wed, 21 Oct 2020, Stefan Powell wrote:
So to answer henrys question: it is absolutely necessary to avoid bulk
boiling of peroxide in your regen. Nucleate boiling will occur. If film
boiling is occuring, you had better increase your regen flow velocity.
Also, there is some thermal decomposition as well -- the Andrews paper on
peroxide mentions that differing results from two different methods of
flow measurement reflect the presence of some oxygen gas in the peroxide
coming out of the cooling system. Alas, he doesn't give numbers.
(I'd thought I had some numbers somewhere about peroxide temperatures in
the Black Arrow engines, but no.)
Also, one downside of cooling with peroxide is that hot peroxide is harder
on catalysts than cold peroxide -- in particular, silver-based catalysts
top out at about 85% peroxide if the peroxide comes in hot, but reportedly
will handle 90% if it's cold. (These numbers undoubtedly depend somewhat
on other variables.)
Henry