Config cleanup and some more improvements #2892
Conversation
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Nice work!! |
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No, not really. I assumed it was a relatively modular design like the H-1, where chamber pressure was increased without making any changes to the injector. |
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If you're increasing chamber pressure wouldn't you also increase the nozzle AR? LR87-AJ-5 -> LR87-AJ-9 style. |
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That's a can of worms I didn't really want to open, and besides, the H-1 and F-1 didn't |
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Under the (speculative) world where the E-1 remains in regular use, I would expect it to get upgrades like the in-regular-use LR87, rather than the one-and-done H-1 and F-1. |
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(one-and-done is slightly unfair to H-1, but the work on them broadly stopped in the early-mid 60s, right? Except for that 250klbf study. The "in regular use" H-1s were remanufactured into RS-27 rather than actually being new engines.) |
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I mean, that was the entire point of the modular design applied to the E-1, F-1, H-1, etc. That it could be upgraded to different roles without significant design changes, unlike first generation engines. And it does get the O/F leaned out in the later versions to help increase performance. |
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Also fwiw, the two datapoints we have on the E-1, the test stand model and the Dynasoar booster proposal, show very similar ISP despite a significant (380 to 468 klbf) increase in thrust |
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Well, IMO it sucks for gameplay reasons to have basically no choice as US but to use LR87s if you want a specific impulse above 290 (discounting F-1), but I take your point. |
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Also if you're renaming configs, you should use the upgrade tool provided (add entries to UpgradeData.cfg ) |
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@Capkirk123 More E-1 partisanship: since it unlocks later than the H-1, would we expect its in-service Isp to be comparable (or higher) to H-1? Or would there be too many losses from the gas generator? Because it has a higher chamber pressure and a higher AR nozzle, and yet a worse vacuum Isp. So I'm confused. And does the UpgradeData.cfg file make sense? |
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Well, the one reliable source, dated May 1960, states an expected performance of 256/291. Throwing it into RPA, that seems to suggest a combustion efficiency similar to the F-1. The Rocketdyne baffled injectors that they used to deal with combustion stability at that scale really hurt efficiency. The F-1 just ran at higher pressure and had the film-cooled nozzle extension. Although such a nozzle extension could also be fitted to the E-1, since it runs at lower pressure, this also hurts sea level ISP. That opens the can of worms as to what the E-1 would be used for. In a Titan-like role, with an airlit core, that tradeoff makes sense. In a more Kolyma's Shadow role, with a monolithic E-1 core (also suggested by the USAF study), this would likely not be performed. I'm not sure using the upgrade cfg is a great idea. The old configs are still there, just deprecated, and the new configs are relatively dissimilar. |
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Obviously, with 1.5 reliable sources, this leaves a lot of latitude for creative config work. I chose the conservative approach, simply mirroring the upgrades applied to the H-1. |
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Sorry, somehow I missed the notifications on these. Yeah, all that makes sense. Likely (as OTL for F-1 and H-1) E-1 upgrades would focus on thrust for a larger LV, rather than squeezing out extra performance. It's possible something like RS-27A might be done, as you surmise (either groundlit with a few UA1207s and a long-burning core, or airlit with many, many UA1207s). Ok, at any rate I'm satisfied with the E-1. Thanks for humoring me. :) Consider this PR reviewed on my account, merge when ready! |
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Unless any further objections exist, I would like to merge this so I can get on with RD-0106/0107/0108 changes without fear of conflicts |
Continue to work on cleaning up engine configs, adding sources, etc.
Also make improvements to a few of the more neglected configs. Changes include:
Although many changes are made, this should not be save-breaking. Many changes were made, but most were minor. The only significant performance reductions were to the NK-15, NK-15V, RS-88, and LAE.