Are Those Nozzles "Thrust Augmented"?
In this article at AvLeak, there's discussion of an Aerojet LOX/Kero booster engine project called HC Boost (emphasis mine) :
A similar engine concept I've talked about with a few friends in the propulsion business is if you took the Merlin-1C upgrade that's been hinted at by SpaceX, and applied that extra pump power they're looking at creating to providing higher flow, lower pressure propellants to a TAN section (say by diverting some of that extra high pressure flow into some sort of a jet pump), you'd be able to get away with a much larger expansion ratio nozzle (with good sea-level Isp), while also nearly doubling the thrust. I really like the idea of a Falcon 1f that can put say 5000lb of payload into LEO for little more than the cost of a Falcon 1e....It's a powerful concept, though I would understand if for now a company like SpaceX is focusing on getting Falcon-1 and -9 flying reliably first. First get it working and working reliably, then add the afterburners...
Which reminds me, I need to go back and do a more detailed article on some of the additional concepts and technical information I've found about Thrust Augmented Nozzles at some point.
Now, the RD-180 is a very high performance engine. It's combustion chamber pressures are actually quite a bit higher than the SSME. When you combine this with the statements in this paragraph (my emphasis again):Dubbed HC Boost, the technology development program is aimed at providing an improved, home-grown alternative to the Russian RD-180, the only other viable current-production hydrocarbon rocket engine. Unlike the RD-180, however, the US engine would be designed to be re-usable for up to 100 missions, have up to 15% better performance and would operate for up to 50 missions between engine overhauls.
The last US-designed and produced hydrocarbon engine was the Rocketdyne RS-27, based on 1960s technology and now out of production. The HC Boost engine, on the other hand, is expected to have higher operability, faster turn time, a longer-life thrust chamber, turbopumps and a new design nozzle.It really does seem to suggest that they might be talking about thrust augmented nozzles. By going with nozzle thrust augmentation, you could get that same high lift-off thrust, and good sea-level Isp without requiring anywhere near as high of a chamber pressure. Which would necessarily lead to less demand on the thrust chamber and pumps.
A similar engine concept I've talked about with a few friends in the propulsion business is if you took the Merlin-1C upgrade that's been hinted at by SpaceX, and applied that extra pump power they're looking at creating to providing higher flow, lower pressure propellants to a TAN section (say by diverting some of that extra high pressure flow into some sort of a jet pump), you'd be able to get away with a much larger expansion ratio nozzle (with good sea-level Isp), while also nearly doubling the thrust. I really like the idea of a Falcon 1f that can put say 5000lb of payload into LEO for little more than the cost of a Falcon 1e....It's a powerful concept, though I would understand if for now a company like SpaceX is focusing on getting Falcon-1 and -9 flying reliably first. First get it working and working reliably, then add the afterburners...
Which reminds me, I need to go back and do a more detailed article on some of the additional concepts and technical information I've found about Thrust Augmented Nozzles at some point.
Labels: Space Transportation, Technology, Thrust Augmented Nozzles
