Heat Radiators on a ship

[zero]

Heres another topic for hard scifi ship design for the layman :wink:

I have heard alot about Heat Radiators, how they take up waste heat from within the ship (or something) and also how Life Support needs a set to keep people from well, cooking themselves in the ship. Also with my current Cstars ship having 4 dtons of a Fusion Powerplant that is powered by hydrogen, shouldnt this be an important feature to be mentioned?

I dont see any mention for this kind of tech in Traveller, even though I figure that a TL 8 - early TL 9 ship probably has them in some capacity.

To those who understand what I'm on about, what about them and how could I implement them if say, I wanted to draw an exterior view of my completed ship?

 

[barnest2]

Give the ship solar panels, but call them heat radiators. They looks like solar panels anyway.

 

[rust]

As Barnest wrote, but just turn them so their "broadsides" are not poin-
ting towards the sun, you would not want the solar radiation to heat your
heat radiators. In other words, solar panels try to maximize solar radia-
tion input, heat radiators try to minimize it.

 

[Captain Jonah]

Under normal circumstances dealing with waste heat is fairly easy, you can dump it into water or even into the air.

In space it is a much larger problem since you have no conductive medium around the radiators. With high density heat sources like the transit drive or a power plant which run for long periods of time you generate far more heat than the surface area of the item can radiate.

You can use the entire ship’s hull as a radiator which is rather uncomfortable for the crew or you can expand the surface area of the hull around the drive or power plant. A larger surface area radiates more.

The easiest way to do this for deep space vessels not worried about streamlining is to fit radiators, as simple as flat metal plates mounted vertically on the hull over the drive.

Find a picture of thunderbird 3 and look at the radiator section; it’s the black section just before the hull bulges out where the drives are. The surface area here (presumably over the power plant) is much larger than the circumference due to the extra area provided by the fins. The more the heat you need to dump the larger or longer the fins need to be. You could have shorter 0.5 – 1m fins running half the length of the ship or a section of larger wings and fins just over the drive room.

Think of the old 50s space ships with those big fins and wings at the back, flash Gordon style.

 

[zero]

So its actually more of a visual thing when drawing the outside of the ship? Fair enough.

There is some math about how much is needed here;

http://www.projectrho.com/rocket/basicdesign.php

It doesnt state about the power generated by fusion power plants (as in my ship), mainly as we havent reached it as a stable tech yet, I think.

Mainly, I was wondering roughly (who could total an exact amount??) how many square metres of heat radiators would be needed to cover a full A-class Engineering (with Reaction Drive and Fusion Power-plant).

 

[rust]

Mainly, I was wondering roughly (who could total an exact amount??) how many square metres of heat radiators would be needed to cover a full A-class Engineering (with Reaction Drive and Fusion Power-plant).

I am afraid that even an "educated guess" would require the power output
of the power plant in Megawatt.

 

[zero]

Lol, I guess I should forget about it and say the entire surface area of the ship has some kind of liquid radiator on it, huh? :roll:

 

[DFW]

Lol, I guess I should forget about it and say the entire surface area of the ship has some kind of liquid radiator on it, huh? :roll:

No need for liquid. Anyway, in Trav it is just handwaved as in reality, you couldn't dump enough heat from a fusion reactor unless you had HUGE, ginormous radiators.

 

[zero]

Fair enough, but that strikes me as... not very hard scifi for Traveller. Well, something I dont need to worry over, anyway

 

[DFW]

Fair enough, but that strikes me as... not very hard scifi for Traveller.

Neither is the J-drive, Grav M-drive, cryo low berth, etc., etc.

 

[zero]

Correct, they are not, but in using a Cstars ship, I had none of those, instead it has the Transit-Drive, a drive which boosts on a straight course in accel/deccel cycles touching a fraction of the speed of light (meaning a trip from Mercury to the Kuiper Belt takes a few months), a normal A-class Reaction Drive and Grav-couches (which work similar to those in Event Horizon).

 

[DFW]

Correct, they are not, but in using a Cstars ship, I had none of those, instead it has the Transit-Drive, a drive which boosts on a straight course in accel/deccel cycles touching a fraction of the speed of light (meaning a trip from Mercury to the Kuiper Belt takes a few months), a normal A-class Reaction Drive and Grav-couches (which work similar to those in Event Horizon).

And?

 

[zero]

Jeez... :?

Well nothing, except these are a little harder equivalents to what you listed and from that, you can see I'm trying to push a little harder scifi into my games than vanilla Traveller.

Also, ffs, this is a topic about heat radiators, something that Traveller doesnt even have rules for.

That And...

:roll:

It doesnt matter anyway as I'm handwaving that and just continuing with the ship construction as is.

 

[DFW]

Also, ffs, this is a topic about heat radiators, something that Traveller doesnt even have rules for.

Right, as any rules would be meaningless from a hard science viewpoint anyway. And, your ship having a fusion PP, would require so much in radiators that it would probably double your tonnage anyway.

 

[rust]

Well nothing, except these are a little harder equivalents to what you listed and from that, you can see I'm trying to push a little harder scifi into my games than vanilla Traveller.

I think your only chance to escape the heat problem in a (semi-) "hard"
way would be to use the heat generated by the power plant for the drive,
by heating a reaction mass (e.g. water) so that it expands (e.g. steam)
and drives the ship. Otherwise there is only handwaving, since even a
10 MW fusion power plant at improbable 90 % efficiency would create
about 1 MW of heat - simply too much to get rid off with radiators of any
size that would look good on a deckplan.

 

[Captain Jonah]

Put something on the out side that looks good. Doesn't need anything on the inside.

Since we cannot do the science just go for artistic. :lol:

 

[zero]

Lol, again fair enough, I'll just make the ship look like it has a liquid radiator coating for a paintjob

 

[rje]

Ships do indeed produce a lot of heat.

Kim Stanley Robinson's Red Mars trilogy -- a very gritty set of books -- used advanced ceramic coils to store heat generated by stealth vehicles. Something similar could be part of the "life support" system of Traveller craft. That's usually how I think of Traveller heat management. It's still fantastic.

I also think the radiator idea is a good one, but for lower tech than most of Traveller assumes. So maybe for 2300AD or your Cstars setting it would feel more appropriate.

 

[DFW]

One quick tip for realism. When designing radiators for vacuum. Never have them facing each other as they just radiate IR into each other. If adjacent, have them at right angles.

 

[Ishmael]

One quick tip for realism. When designing radiators for vacuum. Never have them facing each other as they just radiate IR into each other. If adjacent, have them at right angles.

as per Lambert's cosine law.
They should not be arranged like a cross, however. That would still allow one radiator to radiate onto another panel.
Arranged like the sides of a box is good. And of course, arranged to prevent them from radiating back onto the ship itself.