What do radiator panels do?

[MrabEzreb]

I am currently taking a ship, flying up to > 250000m, getting science, and coming back down. The issue is that my ship keeps exploding from the heat! I have a heat shield, and I am pointed retrograde, but it isn't enough. What do the radiators do, and how to I maximize their potential?

[Caelib]

Radiators are primarily used to dissipate heat generated by engines such as the nuclear one.

In your situation, is your ENTIRE ship protected by heat shield? If you've got parts hanging out, they will generate heat and transfer it to the other parts it touches and your heat shield will not really help you.

Post a screenshot of your re-entry vehicle.

Edited August 16, 2015 by Caelib

[peachoftree]

It's also good to note that IIRC radiators do absolutely nothing on reentry

[Geschosskopf]

Radiators (should) not be any help during reentry. Quite the opposite. Sounds like your problem is you're coming in too steep for your reentry. Come in shallower, make multiple passes if necessary instead of doing it all at once.

Anyway, as to your question....

Basic heat stuff:

* Heat only moves from hotter things to colder things. "Cold" doesn't move, it is merely the absence of heat, and a magnet for it. When you put hot beer in a cooler and dump ice on it, the heat from the beer goes into the ice and heats up the ice, causing some of it to melt. Because the beer has lost heat, it is now colder.

* The rate at which heat moves from hot to cold things is affected by the surface area - to - mass ratio of the objects involved. Thus, a thin, wide, flat object will gain or lose heat faster than if you had the same mass but wadded up into a cube. Radiators use this principle by being thin, wide, and flat, trying to get as much surface area as possible. But for heat to "radiate" out of a radiator, the radiator still has to be hotter than its surroundings, so the heat moves from the hot radiator to the "cold" surroundings.

* Combining these fundamentals, you see that if a ship is hotter than its surroundings, and has a radiator, then the ship will lose heat through the radiator to its surroundings. And because the radiator is losing heat faster than the rest of the ship, it becomes slightly colder than the rest of the ship, so heat from the rest of the ship gets sucked into the radiator and then lost to the surroundings.

* This is why radiators should be detrimental during reentry. During reentry, the flames surrounding the ship are hotter than the ship, so a radiator would suck heat up from the surroundings and pump it into the rest of the ship.

[problemecium]

I suppose it could be realistic if you only put radiators on the back of the ship or in shielded areas. Then you're simply absorbing heat in the front and blowing it out the back, becoming "transparent" to the heating effect.

Dunno if anyone's actually tried this though.

[Pecan]

There are already a couple of threads about this you might like to read:

http://forum.kerbalspaceprogram.com/threads/129763-How-exactly-do-radiators-work-Can-I-use-them-to-help-with-aerobraking

http://forum.kerbalspaceprogram.com/threads/131295-Heat-Radiators%28-%29

[PB666]

radiate - to convert energy of one form into another, to take vibrational energy in the form of object heat and release in the form of black body radiation as previously described by Max Plank E = hv.

[Laie]

I am currently taking a ship, flying up to > 250000m, getting science, and coming back down. The issue is that my ship keeps exploding from the heat! I have a heat shield, and I am pointed retrograde, but it isn't enough. What do the radiators do, and how to I maximize their potential?

Don't waste your time with radiators. With a lot of try-and-error they can be made to work during reentry (although really they shouldn't, cf. Geschosskopf above), but their effect will be miniscule at best.

I guess you're doing a straight up, straight down kind of mission? Plunging into the atmosphere at a steep angle is quite dangerous from 100km, from 250 it's probably not survivable. Take the time to make a proper orbit, and enter more gently.