Since we're discussing in the context of the Raptor engine I'll use
estimates for methane engines. I'll use a rocket engine analysis program to
estimate the possible vacuum Isp with methane fuel:
http://www.propulsion-analysis.com/index.htm
The specs of the Raptor in its latest incarnation are given he
https://www.freelists.org/archives/a...Xl97QZZkJ3.jpg
If you use the cited combustion chamber pressure of 250 bar of the Raptor,
but give it an expansion area ratio of 300, possible with altitude
compensation, then the vacuum Isp can be in the range of 390 s according to
the rocket engine analysis program.
That image of the Raptor on freelists.org site is not available. It's
available he
http://spaceflight101.com/spx/wp-con...17-Musk-19.jpg
Bob Clark
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Carbon nanotubes can revolutionize 21st-century technology IF they can be
made arbitrarily long while maintaining their strength.
Some proposals to accomplish that he
From Nanoscale to Macroscale: Applications of Nanotechnology to Production
of Bulk Ultra-Strong Materials.
American Journal of Nanomaterials.
Vol. 4, No. 2, 2016, pp 39-43. doi: 10.12691/ajn-4-2-2 | Research Article.
http://pubs.sciepub.com/ajn/4/2/2/
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