NK-33 vac T:W, 138. Merlin 1D, vac T:W 180.
Mind, NK-33 in fact does have a higher chamber pressure, 2150 psi to
1410 psi for Merlin 1D.
Chamber pressure does seem to be a significant factor in engine weight,
yeah.
On 12/29/2015 1:48 PM, David Gregory wrote:
It was stated that GG engines are lighter than alternatives. At a given
chamber pressure, that's not the case.
On Dec 29, 2015, at 12:40 PM, David Weinshenker <daze39@xxxxxxxxxxxxx> wrote:
On 12/29/2015 12:02 PM, David Gregory wrote:
There is nothing magical about the GG cycle that makes it lighter.
No, there's nothing "magic" about gas generator cycles - they're a
simple, effective solution. There's something a bit "demonic" about
staged combustion cycles (from the engine development point of view),
though; it's much harder to develop such an engine incrementally: you
sort of have to get everything working at once in order to test-run
anything.
I heard that a number of SSME prototypes were consumed in the
process of discovering a safe startup sequence... it wouldn't
surprise me if there were similar experiences "over there",
during the initial development of the RD-180.
-dave w