Stop nukes from overheating?

[ScottyDoesKnow]

So what's the best way to do this without it looking hideous? I've seen the images with 20 fins sticking off them but that's terrible. I basically have a main 2.5 stack to 4 symmetric 2.5 stacks, and each of those has 3 FL-T400s with nose caps and nukes. I need probably a 5 to 7 minute burn to get to Eve, but end up exploding (the FL-T400s) at about 4 1/2 minutes.

Any way to get around this? If I use multiple small tanks will they take more heat? Some way to disperse it to the 4 2.5 stacks?

Edited May 14, 2015 by ScottyDoesKnow

[Randazzo]

So what's the best way to do this without it looking hideous? I've seen the images with 20 fins sticking off them but that's terrible. I basically have a main 2.5 stack to 4 symmetric 2.5 stacks, and each of those has 3 FL-T400s with nose caps and nukes. I need probably a 5 to 7 minute burn to get to Eve, but end up exploding (the FL-T400s) at about 4 1/2 minutes.

Any way to get around this? If I use multiple small tanks will they take more heat? Some way to disperse it to the 4 2.5 stacks?

If you want to do it stock, you're better off with them attached to larger tanks. Larger tanks have a higher thermal mass and can therefore absorb more heat. Short of adding wings or what-not to act as a heatsink, you could try running the LV-N's at less than 100% throttle.

If you aren't opposed to mods, there's that route too.

[Pax Kerbana]

I had the same problem.

Attach the nukes to the new nosecone adapter (Mk 1 to tiny) and attach these radially to a Mk 3 tank. Can burn at 5/6 throttle until 5k+ dv.

Edit: 6 engines attached this way on the short LF Mk 3 tank. You will need more fuel than this for 5k dv as well as fuel lines.

Edited May 13, 2015 by Pax Kerbana

[n0xiety]

Just use a 5000 size mk3 liquid fuel tank and you should be fine untill your fuel runs out.

[ScottyDoesKnow]

Thanks for all the answers. My problem is that this is an Eve return vehicle so I need to drop them during Eve entry. And currently my 9 X200-32s are both perfect for the Eve transfer (~2700 dV) and needed for the Eve ascent. So I may have to try sticking a bunch of ugly radiator pieces on them.

[ScottyDoesKnow]

Edit: nevermind. See below.

Ended up just throwing some fins on (5 per) and it actually doesn't look too bad. The fuel tanks exploded at exactly 8 minutes of burn (up from ~4:30), which was the goal I was testing to since even the worst transfers should be around 7:30.

Javascript is disabled. View full album

Edited May 14, 2015 by ScottyDoesKnow

[ScottyDoesKnow]

Scratch that. Was just testing temperature so I edited my way into orbit. As soon as I tried launching all the fins pulled the rocket sideways. Back to the drawing board.

[ExavierMacbeth]

Could try using a heat shield as an insulator and running a fuel pipe between it and the engine for fuel flow. Thats what I have been doing to keep mine isolated and from blowing up whatever they are attached to. Even after the Ablator is gone the max thermal on the Heat Shield is something like 3400k (bout 600 higher than the Nerva I think) so by then your already throttling down anyway to keep the Nerva from exploding.

[n0xiety]

Could try using a heat shield as an insulator and running a fuel pipe between it and the engine for fuel flow. Thats what I have been doing to keep mine isolated and from blowing up whatever they are attached to.

If you want to isolate the engine and the rest of the craft use service bay. It won't let the heat to pass.

[ScottyDoesKnow]

Could try using a heat shield as an insulator and running a fuel pipe between it and the engine for fuel flow. Thats what I have been doing to keep mine isolated and from blowing up whatever they are attached to. Even after the Ablator is gone the max thermal on the Heat Shield is something like 3400k (bout 600 higher than the Nerva I think) so by then your already throttling down anyway to keep the Nerva from exploding.

Was excited about this one, pretty easy and looks good. Unfortunately with nowhere for the heat to go the engines blew in under 4 minutes, worse than how long it took the tanks to blow originally.

[Wintersdark]

Yeah, my experience has been that i get the best results with just having oodles of thermal mass to absorb the heat, and Gigantor solar panels mounted close to the engines to help radiate. Not lots, just a couple - they just help.

Ive been running my Nerva's radially as well, attached to small LF tanks which are fed by the large tank they're attached to.

With the radial setup, and 2-4 Nerva's each with a single gigantor solar array, I've not managed to get anywhere close to exploding anything yet.

[ScottyDoesKnow]

Ended up just replacing em with LV-909s. Went from ~2800 dV to ~2500, which still left me with 800 to deorbit with an optimal transfer. Also took the cost down 120,000 (about 10%). Appreciate all the advice though.

[ArmchairGravy]

Yeah, my experience has been that i get the best results with just having oodles of thermal mass to absorb the heat, and Gigantor solar panels mounted close to the engines to help radiate. Not lots, just a couple - they just help.

Ive been running my Nerva's radially as well, attached to small LF tanks which are fed by the large tank they're attached to.

With the radial setup, and 2-4 Nerva's each with a single gigantor solar array, I've not managed to get anywhere close to exploding anything yet.

I've been wondering if gigantors with 1200 max heat are better than multiple 1x6's with 2000 max heat. Anyone know?

[Wintersdark]

I've been wondering if gigantors with 1200 max heat are better than multiple 1x6's with 2000 max heat. Anyone know?

The max heat doesnt matter, its the ability to radiate heat. The little panels are all pretty short, so getting the same surface area would be unwieldly.

The gigantors here though aren't the lynchpin of the operation - thermal mass is. The gigantors just help shed heat while keeping part count down. I've never had one burn up.

[Laie]

I've been wondering if gigantors with 1200 max heat are better than multiple 1x6's with 2000 max heat. Anyone know?

Solar panels don't make the best heat sinks -- while they radiate extremely well, the are slow to pick up the heat (low conductivity). A wing piece radiates just as well, but is more conductive, so it will pick up more heat to radiate.

This means that solar panels can help quite a lot, but shouldn't be the linchpin of your heat management. In which case the 1200 vs 2000 degrees don't matter.

That said, I find that heat generation just plain silly. It may become a good gameplay mechanic, but right now it isn't and I have turned it off.

[Pax Kerbana]

That said, I find that heat generation just plain silly. It may become a good gameplay mechanic, but right now it isn't and I have turned it off.

I agree with this. Haven't turned it off but I do turn off the annoying heat bars. I understand what they're trying to do, and like the concept, but now way are they close to done.

Crazy densities and soup atmospheres are things I can enjoy, toaster rockets I do not.