Cooling the LV-Ns

[jarmund]

I am currently working on my standardized interplanetary tug, and I need to figure out which design allows me to burn a pair of LV-Ns the longest without any parts blowing up.

What I'm basing this around is a set of MK2 parts with fuel lines feeding into a pair of radially attached MK1 Liquid Fuel Fuselage. These fuselages have the LV-Ns on the tail, and those slanted nosecones on the front. When in the shadow of kerbin, 1000km orbit, this allows me to burn for exactly 5 minutes before the MK1 tanks explode (they have less heat tolerance than the engines themselves).

I've tried attaching a bunch of OX-4L 1x6 to the tanks, hoping they mould function as IR radiator (I thought I heard something about this for solar panels), but the result is the same.

Have anyone else experimented with efficient cooling/heat absorbtion? What were your findings for heat-tolerant assemblies?

Edited May 5, 2015 by jarmund

[Gaarst]

Solar panels are really bad radiating heat.

Best thing to do is put the engines as close as possible to the tanks to absorb the heat; and to radiate it, wing parts are the best: best ratio radiating area to mass.

Another thing you can do is anticipate your burn and just pause during it to let parts cool down for manoeuvres that do not require much time precision.

[Randazzo]

I am currently working on my standardized interplanetary tug, and I need to figure out which design allows me to burn a pair of LV-Ns the longest without any parts blowing up.

What I'm basing this around is a set of MK2 parts with fuel lines feeding into a pair of radially attached MK1 Liquid Fuel Fuselage. These fuselages have the LV-Ns on the tail, and those slanted nosecones on the front. When in the shadow of kerbin, 1000km orbit, this allows me to burn for exactly 5 minutes before the MK1 tanks explode (they have less heat tolerance than the engines themselves).

I've tried attaching a bunch of OX-4L 1x6 to the tanks, hoping they mould function as IR radiator (I thought I heard something about this for solar panels), but the result is the same.

Have anyone else experimented with efficient cooling/heat absorbtion? What were your findings for heat-tolerant assemblies?

Apparently wing parts make the best stock heatsinks, you can find a good example here: http://forum.kerbalspaceprogram.com/threads/116993-Helpful-1-0-observations?p=1870791#post1870791

If you aren't opposed to mods, I have a link in my sig that you may be interested in.

[juanml82]

Run them at 90% (hey, look for a copy of 0.90, run the nukes at 100% and tell me how much they last) and use an MK3 tank if possible as the center stage as they soak more heat

[Geschosskopf]

Best solution: Make yourself a ModuleManager cfg file that totally nerfs the heating of the LV-N. I consider this totally legit as the heat mechanics in KSP are demonstratively broken, so it's pointless to be bothered by them.

[THX1138]

OX-4L 1x6 are the wrong solar panels. You need to use the ones that come in a white casing or the gigantic ones.

[jarmund]

OX-4L 1x6 are the wrong solar panels. You need to use the ones that come in a white casing or the gigantic ones.

They work as IR radiators?

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Apparently wing parts make the best stock heatsinks, you can find a good example here: http://forum.kerbalspaceprogram.com/threads/116993-Helpful-1-0-observations?p=1870791#post1870791

If you aren't opposed to mods, I have a link in my sig that you may be interested in.

I just tested, three wings on each MK1 tank, and it lasted 30 seconds longer. So now I'm totalling 5m30s at 100% throttle, which should suffice in most burns.

[THX1138]

The gigantor (I think they're called) and the panels in white casing have radiators on the reverse, according to their descriptions. The OX-4L 1x6 do not have radiators.

[Laie]

And the descriptions are right for once. Just ran a quick test: of the two 1x6 panels, the one with casing radiated twice as much heat. The Gigantor, 12-15 times as much as the cased 1x6 (better when hot, that is, it works best when you need it the most). The 275kg swept wing was better still, like twenty of the small panels.

By weight, the wing wins. It seems that the wing is much better at picking up the heat; running hotter, it can then radiate more. Still, sustained operation will require like 1000kg worth of wing for every engine. Mount them as close to the engine as possible.

[Aerindel]

This ship can run 6 nukes for 30+ minutes until it runs out of fuel. The only part that will overheat and explode are ironically, the gigantor panels mounted up front. The fins in the back are not for heat purposes but to help stabilize the craft during aero-braking.

[THX1138]

The wings might be a bit more effective at radiating heat but that's all they do. The solar panels have two purposes while the wings just have one.

[Aerindel]

Except the solar panels don't really do anything. The most effective way to control heat is to mount the engines on a big tank of cold fuel. Trying to control heat with solar panels only buys you insignificant gains. There is a reason that real heat radiators are not part of solar panels, they are oriented 90º wrong for heat radiation.

Edited May 6, 2015 by Aerindel