3 ms·
I was under the impression that the Raptor was running a full-flow staged combustion, which by definition is neither Fuel-rich nor oxygen-rich.
by Valgrim 6y ago
I was under the impression that the Raptor was running a full-flow staged combustion, which by definition is neither Fuel-rich nor oxygen-rich.
- bryanlarsen 6y agoFFSC means it has two turbopumps, one which runs fuel rich and the other which runs oxygen rich. It doesn't force the thrust chamber to be perfectly balanced, in fact because you can run the turbopumps independently it gives you the freedom to have the mixture be whatever you want: fuel rich, oxygen rich or at the perfect stoichiometric ratio. The perfect stoichiometric ratio would get the highest exhaust velocity, but thrust is mass x velocity, and ISP is relative to propellant mass. Oxygen is relatively heavy, so optimum ISP is fuel rich.