I love it, simple, reliable with enough performance to get the job/mission
done. KIS
Bob Truax's axiom.
K
On Mon, Mar 1, 2021 at 4:23 PM Michael Kelly <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
The original French space launch vehicle, the Diamant, used WFNA and
turpentine in the first stage. They avoided hard starts by incorporating a
250 lbm slug of furfuryl alcohol in the fuel feed line.
Isp was less than impressive; sea level Isp was 203 seconds, vacuum was
233. Not very impressive. However, the chamber pressure was only 255
psia, and the area ratio only 3.6. That allowed them to pressure feed the
propellants, resulting in a very short development cycle. The engine
developed almost 70,000 pounds at sea level, and the vehicle GLOW was just
a little over 40,000 pounds. From a system design standpoint, given their
goals (join the USSR and US as a space launch nation, without breaking the
bank), it was a remarkably good solution.
I expect that Peter Beck, who evidently advised them, knows all of this.
On March 1, 2021 at 6:15 PM, Henry Spencer <hspencer@xxxxxxxxxxxxx> wrote:
On Tue, 2 Mar 2021, Troy Prideaux wrote:
[WFNA/turpentine]
Yeah, it�s a strange selection given the handling issues of the oxidizer.
It also has a reputation for hard starts -- yes, it's hypergolic, indeed
one of the first hypergolic combinations discovered, but it has enough
ignition delay to be a bit marginal.
If I were them, I'd worry a bit about whether successful results with one
batch of turpentine today would translate into success with another batch
tomorrow, given that the composition is not really standardized. I would
particularly worry about whether smooth starts today would become hard
starts tomorrow.
Henry