ProjectThoth has quit [Ping timeout: 198 seconds]
<Bornholio> a lot of times its not can it restart it is can it restart 99% of the time
<Bornholio> if you can't get very high percentages then there is no reason to include restarting and go with a solution that can
VanD has joined #RO
VanD has quit [Client Quit]
VanDisaster has quit [Ping timeout: 204 seconds]
Hohman has joined #RO
VanDisaster has joined #RO
ProjectThoth has joined #RO
ProjectThoth has quit [Ping timeout: 183 seconds]
ProjectThoth has joined #RO
<ProjectThoth> So I think I'm being suckered into a hybrid rocket project.
<ProjectThoth> Anyone got any good resources for this?
<ProjectThoth> I want to seem like I'm competent.
awang has quit [Read error: Connection reset by peer]
awang has joined #RO
<wb99999999> holy this is some high quality video
<taniwha> yeah, very nice
<taniwha> showed it to my wife (who usually isn't interested in this sort of thing), made her want to watch Apollo 13 again
<wb99999999> the J-2 ignition is very spectacular
<wb99999999> it looks better than even the movie imo
<wb99999999> light blueish plume erupt from the nozzle with a bright flash
qwertyy__ has joined #RO
<soundnfury> ProjectThoth: tell them hybrids are H-hard and if they have any sense they'll try pressure-fed liquids instead?
<wb99999999> lol
<ProjectThoth> Really, all things considered?
<ProjectThoth> I'll believe it.
<wb99999999> actually for ammeter rocketry
<wb99999999> hybrid is not that hard
<wb99999999> it's more like replacing the oxidizer in a solid model motor with some liquid
<Bornholio> hybrid is pretty easy compared to liquid, but still start from solids first
<wb99999999> large hybrid model rocket is popular because it bypasses the explosive regulation in some places
<wb99999999> in fact many places in the U.S.
<wb99999999> if you're making a BIG solid you might run into certification problems
<ProjectThoth> I mean, I could sell them on liquids, maybe.
qwertyy_ has quit [Ping timeout: 383 seconds]
<wb99999999> pure liquid is much harder imo
<soundnfury> ProjectThoth: CUSF have been trying a hybrid for some time and getting nowhere slowly
<wb99999999> I have actually tried to design a liquid engine and the first page of math just blow my head to pieces
<ProjectThoth> Is LOX/alcohol a bad choice?
<wb99999999> yes
<soundnfury> ProjectThoth: I'd recommend avoiding cryogenics unless you already have experience with them
<wb99999999> if you really want to go pure liquid
<ProjectThoth> We do have cryogens on campus.
<soundnfury> when we discussed this at CUSF we planned Ethane/N₂O, nicely self-pressurising
<wb99999999> I'd say diesel fuel, with nitric acid or H2O2 for oxidizer
<wb99999999> those are safe and easy to handle
<soundnfury> ProjectThoth: sure, but does anyone in your group have experience making e.g. cryo valves?
<ProjectThoth> soundnfury: I'll check.
<soundnfury> wb99999999: nitric acid... safe... lol.
<ProjectThoth> "safe"
<wb99999999> well better than liquid oxygen right...
<ProjectThoth> I mean, hydrogen peroxide would be nice, I think it's a criminally underused oxidizer.
<wb99999999> liquid oxygen is just a fire hazard...
<soundnfury> peroxide would be my choice, but the rest of CUSF are scared even of that
<ProjectThoth> Plus, I can make the jetpack nerd happy.
<wb99999999> peroxide is probably the best thogh
<soundnfury> I like peroxide, but the question is always what to burn with it.
<soundnfury> (My suggestion of tetrahydrofuran was not well received ;)
<ProjectThoth> Well, there's the ARCA nutters, they're trying to use RP-1.
<Bornholio> getting high enough purity htp is hard, and solids easy, you can even start with candy rockets and still get high enough to need specialized launch venues without silly liquid problems
<soundnfury> Bornholio: only need htp if you want to drive pumps with it
<wb99999999> yep
<soundnfury> otherwise you can make do with something below the critical 70-ish%, which is also less dangerous
<wb99999999> liquid is just so much harder
<ProjectThoth> It's somewhat straightforward to concentrate to near-70%, iirc.
<wb99999999> the amount of math...
<ProjectThoth> Yeah, the competition we're trying to get involved in has three categories: Off-the-shelf solid, in-house solid, and hybrid.
<ProjectThoth> I lean very hard in the direction of "hybrid" because I don't see how we can get a leg up with the other two.
<wb99999999> also I have no idea on how to build an actual liquid rocket even with the engine in place
<wb99999999> solid rocket is just a tube and propellant stuffed in it
<wb99999999> but liquid rocket is some other story...
<ProjectThoth> I currently favor LOX/paraffin, not sure what CUSF was/is using.
<wb99999999> like, you need to have tanks...
<wb99999999> in a fuselage that's aerodynamic but also strong enough...
<wb99999999> just no
<wb99999999> it's too hard...
<ProjectThoth> I mean, in the grand scheme of things, solids have the same problem.
<wb99999999> you don't need tanks, especially not separate ones for a solid
<wb99999999> no worry about feeding
<ProjectThoth> It's a worthy challenge.
<wb99999999> that's why I used the word "fuselage" since it's no longer a simple casing, but a fully fledged container
<soundnfury> finally dug out my paper on "liquids are awesome" http://jttlov.no-ip.org:8080/caseforliquids.pdf
<wb99999999> I have a secret fear of propellant tanks in a makeshift liquid rocket just collapse and went up in a fireball due to stress
<wb99999999> for me personally liquid rocket is just orders of magnitude more complex
<ProjectThoth> soundnfury: So, let me guess, they went with hybrid because they drank the Kool-Aid on how safe they are?
<soundnfury> ProjectThoth: to an extent. Also, they'd already started their hybrid when I first met them
<ProjectThoth> Oh, lame.
<soundnfury> and they thought it would be easy, and they've made no progress in the two years since I wrote that
<ProjectThoth> soundnfury: To be fair, I think the only advantage of a hybrid is that it's something the uni would actually let us do.
<soundnfury> all they've managed to get out of their hybrid is non-choked exhaust full of glowing unburned grains of sugar
<ProjectThoth> Interesting thing about reciprocating pumps. Isn't that what XCOR was planning on using?
<soundnfury> (did I mention they're using sugar/N₂O)
<ProjectThoth> Oh, good god, why?
<wb99999999> ratio?
<soundnfury> they think it's safer
<ProjectThoth> NO NO NO NO NO >__<
<wb99999999> sugar is not safer
<wb99999999> it is not...
<soundnfury> in fairness, they have since switched to some sort of plastic/rubber/thing iirc
<ProjectThoth> I had to argue against N2O pretty hard.
<ProjectThoth> My preferred blend is LOX (or H2O2)/paraffin + iron oxide.
<ProjectThoth> I think that's a decent compromise (and, again, one the uni will actually let us do).
<wb99999999> wow...
<ProjectThoth> But liquid would be nice.
<soundnfury> iron oxide? what/why?
<soundnfury> s/y?/y‽
<Qboid> soundnfury meant to say: y‽iron oxide? what/why?
<soundnfury> damn, regex'd :(
<ProjectThoth> soundnfury: I might be misremembering from the last time I dealt with motors (about three years ago), but isn't that an additive for increasing thrust?
<ProjectThoth> And the moment I say that, I realize how retarded I am.
<ProjectThoth> Aluminum's the fuel, Thoth, not iron oxide.
<soundnfury> it's already oxidised...
<soundnfury> Al makes more sense, yeay
<ProjectThoth> Aluminum burns. >__<
<soundnfury> ProjectThermite
<wb99999999> I think if you can get Aluminum working
<ProjectThoth> But, yeah, additives are something I feel that's worth exploring.
<Bornholio> FeOx is a good ISP adder for sugar rockets as is FeOx and Al mix
<ProjectThoth> soundnfury: Yup, tried to make that once, too. :P
<wb99999999> why just get some very powerful oxdizer and make a VERY powerful solid?
<ProjectThoth> I only failed because I didn't have a ball mill.
<wb99999999> aluminum as a fuel is quite a punch
<ProjectThoth> I mean, I have to sell this somehow.
<ProjectThoth> I kinda like peroxide/kerosene, if we had the option to do liquids.
<wb99999999> I am worried about clogging with kerosene
<wb99999999> would diesel or gasoline work? I mean I know gasoline is kinda dangerous
<ProjectThoth> If only we could do propane!
<wb99999999> isn't propane technically a cryogen?
<soundnfury> straight CHn is often ill-behaved past the lowest molecular weights. Propane could work, but not octane
<soundnfury> wb99999999: you can cool it for density / lower vapour pressure, but for a ground test you don't have too
<ProjectThoth> Pintle injectors, yes or no?
<soundnfury> hell yes
<wb99999999> wait, so you can keep it liquid without pressurizing it?
<wb99999999> or you just pressurize it anyway?
<soundnfury> wb99999999: needs pressure for liquid at RT
<wb99999999> it seems to me a propane tank isn't going to fly very well...
<ProjectThoth> Is nitrogen a bad pressuring gas? Assuming a heat exchanger.
<soundnfury> wb99999999: sure, not flight-weight
<wb99999999> that's what I mean by "technically cryogen"
<soundnfury> but you can worry about liquefying the fuel once you've got the basics working on ground tests
<soundnfury> well, maybe "very soft cryogen"
<wb99999999> for it to fly you kinda need to cool it down
<soundnfury> it's not gonna cause e.g. liquid air to drip off your pipes
<wb99999999> liquid air sounds very scary for some reason
<wb99999999> maybe it is
<soundnfury> liquid air is a good way to cause accidental kabooms :(
<wb99999999> yep, my fear was rational after all lol
<soundnfury> btw, beware: commercial "Propane" is usually a mixture of alkanes depending on local climate, blended to have a suitable vapour pressure at typical temperatures
<soundnfury> e.g. in warm climates it may be mostly butane
<ProjectThoth> Is helium better?
<ProjectThoth> soundnfury: Noted.
<wb99999999> isn't helium expensive?
<ProjectThoth> Right, which is why I was wondering if nitrogen was an OK option.
<soundnfury> ProjectThoth: I think nitrogen is fine for pressurisation, though it depends what it's in the tank with (i.e. temperature)
<soundnfury> but self-pressurisation is much nicer if you can do it
<ProjectThoth> Pressurizing the peroxide tank.
<wb99999999> so I checked propane
<soundnfury> ProjectThoth: ah, right
<ProjectThoth> Unless it's possible to self-pressurize.
<ProjectThoth> But no HTP, so.
<wb99999999> it supposedly have a lighter molecular weight than kerosene and the like?
<wb99999999> correct me if I got it wrong
<soundnfury> ProjectThoth: nah, the only thing perox could self-pressurise under is the O₂ from decomposition, and that's a hairy proposition
<ProjectThoth> soundnfury: Yeah, that could be hairy.
<soundnfury> wb99999999: yeah, propane is C₃H₈
<ProjectThoth> I'm thinking of a graphite nozzle and using graphite steering vanes.
<wb99999999> so it in theory should have a better Isp...except we don't know our oxidizer yet
<wb99999999> I have a crude idea
<wb99999999> if you're launching your liquid through the atmosphere
<wb99999999> why not make the nozzle air-cooled?
<ProjectThoth> soundnfury: Oh, what'd you consider for ignition? I'm, stupidly, partial to the Russian method.
<wb99999999> don't know if this will work or not
<soundnfury> ProjectThoth: my baseline idea was e-match to light off some Mg under a slow-flow of oxidiser
<ProjectThoth> That is exactly what I was thinking.
<ProjectThoth> (the Russians use a remote-controlled match, basically)
<wb99999999> what if we have an air ram or something and we vent the air through the nozzle to cool it
<ProjectThoth> Well, considering the nitrogen exchanger...
<wb99999999> oh, okay
<wb99999999> then this is redundant
<ProjectThoth> But I prefer graphite and ablative, generally speaking.
<wb99999999> if you can get ablative going that'd be perfect
<wb99999999> it's the preferred method after all
<ProjectThoth> Fortunately, I have a trick up my sleeve that won a science fair...
<ProjectThoth> I think with some adaptation, I could probably get it to handle the temps we're talking about here.
<ProjectThoth> Or, well, wood. :P
<wb99999999> it's the Chinese wooden heat shield all over again \o/
<wb99999999> but yes, I've heard about wood charring and ablating away under heat
<soundnfury> ProjectThoth: umm, did you see the design study at the end of my paper?
<ProjectThoth> It's not the worst of ideas, I would trust my life to an oak heat shield.
<ProjectThoth> soundnfury: Still reading it.
<soundnfury> *cough* wood.
<ProjectThoth> soundnfury: THE POWA OF COPPA
* soundnfury raises an eyebrow
<ProjectThoth> Shitty reference to a stupid joke, I'll get the link.
<soundnfury> power of _cooper_, maybe xD
<ProjectThoth> (nsfw language warning)
<ProjectThoth> 10/10 reply, worth.
<ProjectThoth> Is it okay if I share this with the team? I think they need to see it.
<ProjectThoth> (the paper)
<awang> Is there anything that can cause a part to break when colliding with the ground at a velocity below its staed crash tolerance?
<awang> And it's not even technically touching the ground
<awang> To be more specific
<awang> I have a bunch of science things in an interstage fairing
<awang> Fairing base is sitting on top of a decoupler and proc avionics core
<awang> Package lands on top of the decoupler
<awang> At ~11 m/s
<awang> But the interstage fairing breaks
<awang> And nothing else
<awang> Interstage fairing crash tolerance is supposed to be 12 m/s
<awang> Any idea what's going on?
<soundnfury> ProjectThoth: sure, go ahead
<ProjectThoth> soundnfury: Thanks for the consultation! I hope you're not charging because I might pick your brain some more. :P
<soundnfury> awang: KSP physics is going on :P
<ProjectThoth> (and I am broke, just filled my gas tank)
<soundnfury> ProjectThoth: np, when you consider how little I really know it'd be _fraudulent_ of me to charge xD
<soundnfury> (remember, just because the paper is in LaTeX and therefore looks professional doesn't mean I know what I'm talking about ;)
<ProjectThoth> soundnfury: Hey, you know way more than I do, or at the very least have refined bullshitting to the art form it is.
<ProjectThoth> Either way (bullshitting or facts), I'd be happy to learn.
<ProjectThoth> *am literally a geologist involved in a rocket project
<soundnfury> yeah well I'm a programmer _not_ involved in a rocket project, so...
<soundnfury> if you start building actual hardware, a year from now you'll know more than me ;)
<ProjectThoth> Oh, we're supposed to launch by the end of 2018.
<ProjectThoth> I'll invest in a blast shield, don't worry...
<soundnfury> hehe
<ProjectThoth> I mean, I wanted to lobby our infant rocket division into doing suborbital spaceflight.
<ProjectThoth> (no, not launching babies)
<ProjectThoth> If Copenhagen Suborbitals can do it, then so can a motley crew of engineers and one guy who looks at rocks.
<soundnfury> it's... not rock science?
<ProjectThoth> It's hardly rock science.
<ProjectThoth> Anyway, I'm out. \o
ProjectThoth has quit [Quit: +++out of cheese error+++]
<wb99999999> Using a vacuum engine as a sustained is a) reasonable or b) wasteful?
<wb99999999> sustainer*
TM1978m has joined #RO
Wetmelon has quit [Ping timeout: 204 seconds]
riocrokite has joined #RO
<awang> Anyone know what the approximate fuselage diameter of the B-52 is?
<awang> Seeing if I can't make a reasonable approximation for the B-52, and some stats are harder to find than others
Orkeren_ has quit [Remote host closed the connection]
Orkeren_ has joined #RO
<riocrokite> awang: you can try to calculate diameter from dimensions applied to the drawing
<riocrokite> https://i.pinimg.com/originals/ce/2e/a1/ce2ea19c356c7cb9500de49c173f2f2a.gif however this seems to be some kind of prototype
wb99999999 has quit [Ping timeout: 180 seconds]
Maxsimal|Work has joined #RO
Hohman has quit [Quit: ChatZilla 0.9.93 [Firefox 56.0/20170926190823]]
Pap has quit []
Pap has joined #RO
<Pap> Hey Maxsimal|Work I am not around as much as I like to be, school, work and a new baby have whisked me away
<riocrokite> congrats!
<Pap> Thanks!
Senshi has joined #RO
riocrokite has quit [Quit: http://www.mibbit.com ajax IRC Client]
Rokker has quit [Quit: Connection closed for inactivity]
schnobs has joined #RO
<schnobs> o/
<Maxsimal|Work> Pap: Sorry I was afk in a long-ass meeting anyway, glad to hear from you. I feel like we need to get momentum back. Did you get many replies on that form you created for mission costs? I got sick of failing at contracts so I'm gonna look at cost balance a bit this weekend.
xShadowx has quit [Quit: KVIrc 4.9.2 Aria http://www.kvirc.net/]
xShadowx has joined #RO
ferram4 has quit [Ping timeout: 383 seconds]
VanDisaster has quit [Read error: -0x1: UNKNOWN ERROR CODE (0001)]
Orkeren_ has quit [Remote host closed the connection]
ferram4 has joined #RO
VanDisaster has joined #RO
Hypergolic_Skunk has joined #RO
Maxsimal|Work has quit [Quit: Web client closed]
TM1978m has quit [Ping timeout: 383 seconds]
egg|afk|egg is now known as egg
Maxsimal has joined #RO
<Maxsimal> Anyone know which mod(s) might contain a gemini capsule compatible with RP0?
<schnobs> FASA used to have a very fine one. If it's no longer compatile, though....
<schnobs> (I honestly don't know)
wb99999999 has joined #RO
<wb99999999> morning
<awang> !tell riocrokite You're a lifesaver!
<Qboid> awang: I'll redirect this as soon as they are around.
<awang> Does anyone know of any parts that have a "proper" airfoil shape?
<awang> Realized a bit ago that pretty much all the wings I've seen are flat slabs, so all the lift has to come from AoA
<awang> Unless that's where the majority of lift comes from anyways
awang has quit [Read error: Connection reset by peer]
awang has joined #RO
<awang> Did I miss anything?
Wetmelon has joined #RO
<wb99999999> no sir
<wb99999999> no one said anything yet
<Maxsimal> thanks schnobs, I'll check that out.
<Maxsimal> awang: In supersonic flight, afaik, it's all AOA, slim symetrical wing shapes are typical, but I don't know of any good wings for subsonic flight. You could ask Ferram if wing profile shape matters for lift, but I kinda doubt it does.
<ferram4> FAR abstracts away all the wing profile effects. Fundamentally they're not useful except for subsonic flight, which very few people are doing.
<ferram4> The results that FAR uses are approximately equialvent to a NACA 6A-series airfoil with no camber.
<Maxsimal> I shouldn't have even answered, just should have made ferram's name highlight :P
<wb99999999> when FERRAM tells you about how FAR works
<awang> That's quite enlightening
<awang> Thanks!
<awang> Didn't know profile wasn't important for supersonic flight, either
<ferram4> Well, at least for lift.
<ferram4> It'll affect drag, certainly.
<ferram4> But really, the ideal wing profiles for supersonic flight are sections of 2 ciruclar arcs (top and bottom of the airfoil), a diamond, or a squashed hexagon.
<ferram4> They all suck donkey balls for subsonic flight, which is where the engineering comes in: how to make a wing that isn't draggy as fuck for supersonic flight but actually lets the plane take off without needing F-104 amounts of speed on the runway
<awang> So what wing profiles actually end up being used?
<ferram4> NACA 6A-series, or similar shapes.
<ferram4> They weren't designed for it originally, but they're a decent compromise.
<ferram4> Not the least draggy at supersonic speeds, but to make them less draggy would make them stall at lower AoAs.
<wb99999999> but also the design of the plane as whole helps too right?
<wb99999999> LERX, body-lift etc.?
<ferram4> Yes, but that gets much more complicated.
<awang> Any advice for proper area ruling when designing a plane in KSP? Seems like it'd be pretty hard to get the kinds of subtle variation in fuselage diameter that real-life aircraft have
Wetmelon has quit [Ping timeout: 204 seconds]
Theysen has joined #RO
Wetmelon has joined #RO
schnobs has quit [Ping timeout: 186 seconds]
lamont has quit [Ping timeout: 198 seconds]
lamont has joined #RO
Theysen has quit [Quit: Leaving]
aradapilot has quit [Remote host closed the connection]
aradapilot has joined #RO
qwertyy_ has joined #RO
qwertyy__ has quit [Ping timeout: 204 seconds]
lamont_ has joined #RO
lamont has quit [Ping timeout: 183 seconds]
lamont_ is now known as lamont
Rokker has joined #RO
Senshi has quit [Read error: Connection reset by peer]
<awang> What tank utilization should be used for B9 proc wings?
Hypergolic_Skunk has quit [Quit: Connection closed for inactivity]
wb99999999 has quit [Ping timeout: 180 seconds]
<awang> Uh
<awang> Apparently the B-52 wing root is 2 meters thick?
Probus has joined #RO
<awang> Seems... big
<awang> B-9 proc wings only go up to 1 meter thick
<awang> So much for a realistic-ish recreation
<awang> Wait no
<awang> I'm dumb
<awang> Never mind
<awang> ferram4: If FAR abstracts away wing profile effects, does that mean that the size/shape of the leading/trailing edges for wings doesn't matter much?
<ferram4> It does not matter, but you may want to make it not look stupid for aesthetic reasons.
Wetmelon has quit [Ping timeout: 204 seconds]
<awang> I guess a better question might be what *does* matter when messing with B9 proc wings?
<awang> Besides the things that fall into the "base" category in the GUI
<awang> i.e. length, width, offset, thickness?
<ferram4> Increasing the length of the edges does affect the aero, just the same as if you increased the equivalent base parameters.
<ferram4> Thickness tends to be more sueful in handling area ruling
<awang> Makes sense
<awang> Is there a way to tell how "good"/"bad" your area ruling is in the editor?
<awang> Some kind of qualitative thing that indicates whether you should spend the time optimizing that
<awang> Like I know about the yellow area curve thing
<awang> But I'm not sure whether to interpret a particular curve as "eh, it's good enough" or "oh crap that's going to be causing a lot of issues later on"
<awang> Does distance from the plane axis give a hint?
ProjectThoth has joined #RO
egg is now known as egg|zzz|egg
Maxsimal has quit [Quit: Web client closed]
TM1978m has joined #RO
<Probus> I asked this before, but I was having connection problems. Does anyone know of a good mod(s) that go with ion type propulsion?
<Probus> For really long burns.