[1.8+] Real Fuels

[J_Davis]

Was trying to think of three options for each engine. Couldn't come up with one for that spot so I put FOOF. It's my default "uh, whatever." and a running joke I have with a friend who insists on actually trying to design RL rockets that use insane fuels/oxidizers like ClF3 and FOOF.

I wasn't going to worry about american/soviet/european for the stockalike, seems less of an important concern.

Thanks for the fuels suggestion, however. I see what you mean about not wanting more than one Hydrazine derivative.

Edit:

Okay, I must be an idiot, but where can I find the ideal mixes for setting up the new fuel's mixture ratios when configuring engines? I can't seem to find out how much LH2 to how much LOX for rich, lean, and balanced mixtures. I figure I can just adjust the 'ideal' mix to get in-space rich and at-ground lean mixes, but I can't for the love of me figure out how to determine the ideal mass mixture ratios.

Edited January 4, 2014 by J_Davis

[AdmiralTigerclaw]

Ah... ClF3.

The chemical that makes even the stereotypical mad scientist go "... Nope. NOPE NOPE NOPE NOPE!"

[J_Davis]

Ah... ClF3.

The chemical that makes even the stereotypical mad scientist go "... Nope. NOPE NOPE NOPE NOPE!"

FOOF's worse.

[NathanKell]

dlrk: (Inhibited) Red Fuming Nitric Acid was an early storable oxidizer. Slightly more stable than dinitrogen tetroxide, but worse performance. Often used with an amine or a mixture of amines (TONKA-250, Aniline, etc.) or with UDMH.

Dragon01, nope, Vostok used *Nitrous Oxide* (or thus has said every source I've seen, and the source's asmi's seen in Russian). For fuel it used TG-02, the Russian name for TONKA-250, a mixture of amines.

Nitric Acid was first an American storable, notably used on the WAC Corporal (Frank Malina's / JPL's early sounding rocket) with Aniline, another amine.

According to everything I've seen MMH actually has slightly worse specific impulse than AZ50, but it's enough denser that on balance you get better performance.

J_Davis: I suggest NTO/UDMH, hydrolox, and either KHP, or HZ as monopropellant, as your three for O.

For optimal mixtures I use this: http://www.thespacerace.com/forum/index.php?topic=2583.0 (check out Bob Braeunig's post midway down).

But note that real engines almost never use the "optimal" mixture rate because it isn't, in practice.

You should also definitely look at this page: http://alternatewars.com/BBOW/Space/Propellants.htm and note how expansion ratio changes optimal mixture ratio.

Other pages to look at (from Bob Braeunig again): http://www.braeunig.us/space/propel.htm and http://www.braeunig.us/space/propuls.htm

[J_Davis]

J_Davis: I suggest NTO/UDMH, hydrolox, and either KHP, or HZ as monopropellant, as your three for O.

For optimal mixtures I use this: http://www.thespacerace.com/forum/index.php?topic=2583.0 (check out Bob Braeunig's post midway down).

But note that real engines almost never use the "optimal" mixture rate because it isn't, in practice.

You should also definitely look at this page: http://alternatewars.com/BBOW/Space/Propellants.htm and note how expansion ratio changes optimal mixture ratio.

Other pages to look at (from Bob Braeunig again): http://www.braeunig.us/space/propel.htm and http://www.braeunig.us/space/propuls.htm

I am going to use HZ as an O monoprop.

As for never using ideal mixes, I was aware of that. I wasn't going to go messing with expansion coefficients though. I was just going to go on a rule of thumb that I'd heard. Low stages lean, upper stages rich, in space, turn the richness to 11. I usually try and remember to put ideal in single quotes to emphasize that.

I was thinking that if the 'ideal' mix were F:O Fuel to Oxidizer, I'd change it to .9*F:O for leaner stages and 1.1*F:O for richer stages, with the O engines possibly running 1.2*F:O

Btw, will the next version of RF allow us to change the mix, like in the S-II?

Edited January 4, 2014 by J_Davis

[Guest]

Dragon01, nope, Vostok used *Nitrous Oxide* (or thus has said every source I've seen, and the source's asmi's seen in Russian). For fuel it used TG-02, the Russian name for TONKA-250, a mixture of amines.

Bah, you're obviously right. It's N2O/amines. Nitric Acid was used with UDMH on Luna Ye-8 landing stage and on some other early spacecraft. I dunno what I've been thinking of when I said nitric acid/amines.

[NathanKell]

I wasn't suggesting messing with expansion coefficients per se, just taking note of broad strokes (L->L+/A->U->U+/O) in increasing expansion ratio, and using that to figure optimal mixtures (which you're doing). Although...going by that chart comparing mixture ratio and expansion, looks like at least for hydrolox larger expansion ratios do better with leaner mixtures!

[J_Davis]

Yeah. I am almost done, now it's just figuring out where my mistakes are, some of the output columns are saying #REF and #N/A

[NathanKell]

It only matters if the output column on Engines has errors. The others are expected to sometimes have errors (if you specify <3 mixtures, for example, or if there isn't a valid engine on that line)

[J_Davis]

There were errors on the output column. I dove into the code and found that each engine is trying to read the mixtures of the next engine on the list rather than it's own, causing all kinds of bad references.

[NathanKell]

Ah, yeah. You have to fill down again both there and in EngineOut whenever you insert or remove rows. (That's the first thing the Docs page says, IIRC).

Unless the one I uploaded was already doing that? <blush>

[J_Davis]

Ah, yeah. You have to fill down again both there and in EngineOut whenever you insert or remove rows. (That's the first thing the Docs page says, IIRC).

Unless the one I uploaded was already doing that? <blush>

The one you gave me was doing that. I've not added or removed rows.

Now I'm just scratching my head over the LV-N throwing out a #VALUE error.

[NathanKell]

1. Oops. Also, I thought you were planning to add all the engines from MFS3.3? (And any other engines that should be there...)

2. Ah, I didn't think you were touching the NTRs. Um. Not sure it's quite set up for them. Let me check.

[Chestburster]

May i ask what engines you have already added to the sheet? I started yesterday from scratch adding in all the engines to my sheet that were supported pre .23.

[J_Davis]

I am/was planning on doing them all. Though right now I was focussing on KW and the Stock engines. I have to familiarize with the others.

I fixed the LV-N problem, there was just 1 missing lookup that I added in.

--

Ah, hello Chestburster. I just did KW and Stock. I did it from scratch as well.

Here's what I've got ATM.

-DELETED-

There's some real big mistakes in my SRBs.

--

If that saves you time and you want to take it back over, I'm fine with that Chestburster.

Edited January 4, 2014 by J_Davis
Just noticed the one before.

[Chestburster]

We could join forces if you want (although I won't be at home before Tuesday). Sending you a pm with my file.

[J_Davis]

I'm happy to work with you. Having someone else looking at these numbers would make me more confident in the balance.

[Chestburster]

MFT/RF has always been a crowd sourced project in terms of mod compatibility, so I'm happy too if more ppl are working on it (so i have more time to actually play the game. Only left kerbin system 2 times in the last 4 months xD )

[J_Davis]

MFT/RF has always been a crowd sourced project in terms of mod compatibility, so I'm happy too if more ppl are working on it (so i have more time to actually play the game. Only left kerbin system 2 times in the last 4 months xD )

I rarely even make it to the Mun, as I'm often wrestling with mods. But every time I give up and go back to stock, I miss the challenges.

[NathanKell]

Definitely a crowd-sourced project. Great you're both willing to work on it!

I will my Calcs upload with support for NTR. It will include adding nuclearFuel with a tiny ratio as a propellant, and Starwaster's alternator and generator values and nuclearFuel supply.

[J_Davis]

I will my Calcs upload

Verily, the power of the atom shall be unleashed up on us.

[NathanKell]

Wow, that was a hilarious grammar typo, since it was only weird, not wrong/non-understandable.

Anyway, uploaded. Now fully supports Type N (it will write the alternator, generator, and resources, based on thrust and Starwaster's values).

[NathanKell]

Also, if you do start changing NTRs, delete the cfgs that change them (Squad_modularEngines etc) or you'll hang on load because you're modifying them twice.

[Kalista]

Hey Nathan with the new stockalike engine configs ( released on 1/3) My low tech rocket now is having a near impossible time flying straight. At about 30 km if the pitch goes below 30 it starts to pull to the right and roll left after 70 km the roll stops and it turns about 50 degrees left and sticks there overriding sas completely. I have an output log of when I last played and it happend and i could fraps the rocket behaving like that as well if needed. Also the engine for my second stage seems to not matter each one I've tried has reproduced it.

[NathanKell]

Output_log would be nice. Also, what other mods? Are you using an autopilot? FAR?